The Yard List(s), Part 21

Uh-oh, eleven days since my last update on leafminers and sawflies in my yard… Let’s see what’s happened since then.

I’ve collected Phytomyza origani mines from the oregano patch by the front door on several different occasions, to ensure that I have sufficient reared adults to properly document the presence of this species in North America. In all of the mines I’ve found, the puparia have been formed inside the leaf, with one exception. A puparium appeared at the bottom the rearing vial with leaves I’d collected on June 26, and on July 11 this fly emerged from it:


This is a Calycomyza rather than a Phytomyza. As I mentioned when I first found the mines, no North American leafminer is known to feed on oregano. My guess is that this is C. menthae, which I have mining beebalm (Monarda) in my yard and has also been reared from other mint genera (Lycopus, Mentha), but unfortunately identification of females like this one is hopeless, so this will have to remain an educated guess for the time being.

On July 13 an adult Parornix emerged from a paper birch leaf I’d collected on June 26 (a second attempt after the first mine I collected produced a braconid wasp instead of a moth). In theory this should mean I now know which of the five birch-feeding Parornix species I’ve got, but they all look pretty similar. It might be P. vicinella, but I’m not entirely convinced.


On June 17 I had collected a number of Caloptilia leaf rolls on pin cherry, and some braconid wasps emerged, and then a couple of non-leafmining caterpillars appeared, which I moved to other containers. Then on June 14, this adult Parornix appeared—apparently having emerged either from a mine that I mistakenly associated with the Caloptilia rolls, or from a mine that wasn’t there yet when I collected the leaves, which are too deteriorated now to determine its source.


Although this is mighty similar to the birch Parornix above, Dietz’s (1907) key takes it somewhere entirely different because the cilia at the apex of the wing are not black-tipped. If it’s a species that has been reported from cherry before, it would seem to be P. crataegifoliella, but I’m not confident about this one either.

Also on July 14, I discovered that two adults (a male and a female) had emerged from the soil into which five aspen-feeding “slug” sawflies (Caliroa) had burrowed on or before June 27. Caliroa species are supposed two have just one generation per year, with adults emerging in spring, but no Caliroa species are known to feed on aspen so I guess we shouldn’t expect this species to conform to what is known…


On the same day I discovered that a couple of Acordulecera larvae I’d collected from butternut leaves on June 17 (burrowed by June 22) had emerged as adults. Another genus that isn’t supposed to do that… but it seems like this wasn’t a fluke, because I think I’ve now seen three successive groups of Acordulecera larvae feeding on that same butternut sapling this season.


On a walk around the yard I found two giant silkmoth caterpillars (Saturniidae) on one of our two little tuliptree saplings.


At first I thought they might be larvae of the tuliptree silkmoth (Callosamia angulifera), a tuliptree specialist that I’ve never encountered, but after a little investigation I determined that they’re promethea moths (C. promethea), which include tuliptree in their diverse assortment of host plants. Tuliptree silkmoth caterpillars (and adults) typically hang out well above ground level and are unlikely to be found on a little sapling like this one.

Three days later they had both molted (one not yet totally free of its previous skin and head capsule) and were resting together on the underside of a leaf.


Back on the evening of the 14th I found a couple of Agromyza mines on some sunflowers (Asteraceae: Helianthus annuus) in our vegetable garden.


The only Agromyza known to feed on Helianthus is A. ambrosivora, but this is based on a single rearing from mines Julia and I found in Colorado five years ago, so it’s certainly possible that it isn’t the only species using this host. I collected this mine just in time; right after I picked the leaf, I noticed that one of the larvae was already poking out of it:


Here’s its puparium the next morning:


Leafminer #129: Agromyza ambrosivora (Agromyzidae).  It will be a while before I confirm the identity of the sunflower miner in the garden, but in the meantime I’ve found definite A. ambrosivora mines on ragweed (Ambrosia artemisiifolia) around the yard.


The sawfly larvae I found on the shadbush by the garage on July 11 (which are probably an Arge species) have voracious appetites, and I’ve had to collect new leaves for them every day or two. On July 15 I found one of them molting:


Leafminer #130: Stigmella intermedia (Nepticulidae).  I’d been watching for mines of this tiny moth on the sumac around the yard for a while without seeing anything, and then suddenly on the 17th there were several old, brown ones on a branch overhanging the driveway, which I walk past every day. Not paying enough attention I guess!


On Monday (the 20th) I decided I’d better do a focused leafminer search around the yard to see what else I’d been missing.

Leaf (stem) miner #131: The first thing I found was this mine on a Canada goldenrod (Asteraceae: Solidago canadensis) stem right by the chicken run.


As far as I know no one has ever reported finding a stem mine on goldenrod before. The agromyzid fly Phytoliriomyza arctica is known to mine stems of other Asteraceae genera in Europe, and adults have been caught on goldenrod in Canada. Possibly this is that species, but it could also be some unknown Ophiomyia (I did rear Ophiomyia adults from stems of silverrod, Solidago bicolor, last year). The larva is still feeding away toward the tip of the stem, so maybe I’ll get to find out what it is.


Sawfly #37.  I spotted this striking larva resting on the underside of a smooth goldenrod (Solidago gigantea) leaf in the “lower nut orchard.”


It had a freshly-molted look, and I found its previous skin on the underside of another leaf a few inches above it.


Notice how, unlike the promethea moth, the sawfly larva’s head capsule stayed attached to the rest of its exuviae. This is a consistent difference between lepidopteran and sawfly larvae and applies to leafminers as well. This larva was totally unlike the ones I previously found feeding on goldenrod leaves around the yard, and I can’t be sure what its actual host plant was. The only tree it could have fallen from was a sugar maple; if it wandered onto the goldenrod from a neighboring plant, the most likely suspects would be blackberry and jewelweed. It looked prepupal to me and was acting restless, so I dropped it in a jar of soil and it immediately burrowed down. What emerges (in a few weeks? Next year?) may not be a sawfly, because it had a yellow egg of a tryphonine ichneumon wasp right behind its head. Spencer Monckton suggested this larva is probably a Tenthredo, and a Google image search for that genus did turn up some similarly patterned European species.


Leafminer #132: Phytomyza astotinensis (Agromyzidae), on Canada goldenrod.  This looks just like the mine of P. solidaginophaga, which was active back in May, but it was found on a leaf that didn’t exist yet when the last P. solidaginophaga larva dropped to the ground.


I found this mine of a Cerodontha species (Agromyzidae) on a bract of nodding sedge (Cyperaceae: Carex gynandra). I suspect it was made by C. (Dizygomyza) morosa, but I couldn’t swear it’s not C. (Butomomyza) angulata, which I’ve already listed for the yard (found on deertongue grass), so I won’t count it as a separate species for now. There is a puparium in the mine, so I may end up with an adult fly. There are no records of any leafminer from this particular sedge species.


The promethea caterpillars were still on the tuliptree sapling—one munching away on a leaf with a Phyllocnistis liriodendronella mine.


Leafminer #133: Bucculatrix sp. (Bucculatricidae), on red oak (Fagaceae: Quercus rubra). A few weeks ago I found mines of an undetermined Bucculatrix on this same young red oak, but was unable to find larvae to collect and rear. Now there are cocoons of two different species on the leaves. This stocky one, from which the adult moth has already emerged, reminds me of B. trifasciella but I wouldn’t swear it’s that species…


…and then there’s this pure white, more finely ribbed, and more elongate one, from which an adult might still emerge:


Leafminer #134: Neurobathra strigifinitella (Gracillariidae), on Chinese chestnut.  The larva of this moth mines largely in the midrib, sometimes (as in this example) expanding the mine into a blotch toward the tip of the leaf blade.


Now in the “upper nut orchard,” I saw this rosy maple moth (Saturniidae: Dryocampa rubicunda) caterpillar on the underside of a red maple leaf.


Leafminer #135: Coptodisca splendoriferella (Heliozelidae), on black cherry (Rosaceae:  Prunus serotina).  The leaf in the photo below has mines of five different larvae, two of which survived to maturity, at which point they cut out little oval leaf pieces to form their pupal cases.


Leafminer #136: Stigmella slingerlandella (Nepticulidae), on choke cherry (Rosaceae:  Prunus virginiana).  The larva of this species is much paler than the green larva of S. prunifoliella, and its mine gets substantially wider, often forming a distinct blotch. Also, the mine of S. prunifoliella always begins at the midrib, whereas this mine started above the top of the photo and then crossed the midrib. I don’t think it caused that brown, necrotic area, but it clearly passed through it while the tissue was still green.


The larva popped out of the leaf the next day…


…and by yesterday it had spun its tiny cocoon in the moist wad of toilet paper at the bottom of the rearing vial.


Leafminer #137: Stigmella corylifoliella (Nepticulidae), on one of our cultivated hazelnuts (Betulaceae: Corylus ‘medium long’).


I’m happy to say that plant actually has made some nuts this year, though I assume rodents or blue jays will swipe them all right when we’re starting to think about harvesting them.


Leafminer #138: Calycomyza flavinotum (Agromyzidae). There was a lone larva mining in the spotted Joe-pye weed (Asteraceae: Eutrochium maculatum) we planted in the front yard last fall.


The burdock at the edge of the yard is currently much more popular with C. flavinotum.


The eminently furry Bombus perplexus was enjoying our blooming oregano. I don’t remember seeing this species in our yard before. Although I don’t pay nearly as much attention to flower visitors as to herbivores, this is the fourth species of bumble bee I’ve photographed in the yard.


Also a lovely little orange mint moth (Crambidae: Pyrausta orphisalis), whose larvae also feed on mints, but apparently only on Mentha species and not oregano.


Leafminer #139: “Antispila oinophylla (Heliozelidae), on summer grape (Vitaceae: Vitis aestivalis). The genus of this moth will likely have changed by the next time you hear from me.


I’ve been troubled by these agromyzid mines on our apple mint (Lamiaceae: Mentha suaveolens) ever since I saw one floating in Julia’s water glass a few weeks ago. I’ve been checking the plants ever since and have been unable to find another until now. They don’t really match any of the known mint miners, but they may just be weird mines of Calycomyza menthae.


Leafminer #140: Stigmella villosella (Nepticulidae), on a blackberry growing under the solar panel. A good day for Stigmella mines!


Leafminer #141: Aristotelia isopelta (Gelechiidae), on evening primrose (Onagraceae:  Oenothera biennis). This one was just getting started and I doubt I would have noticed it if I hadn’t been specifically looking for it. I wrote about my initial discovery of this mine here, and this moth is featured in my “Native Plants as Insect Habitat” slideshow that you can now watch here.


The same evening primrose plant had a larva of Waldheimia carbonaria, another sawfly with multiple generations per year.


I saw a number of case-bearing leaf beetle larvae (Chrysomelidae: Neochlamisus eubati) wandering about on blackberry leaves and nibbling them from the cover of their portable poop thimbles.


Also on the 20th, this adult Parornix emerged from a hawthorn leaf I’d collected by the mailbox on July 7. This one I do feel comfortable calling P. crataegifoliella.


Leafminer #142: Agromyza rudbeckiana (Agromyzidae), on the Heliopsis along the driveway. I noticed a brown leaf tip on Monday but couldn’t convince myself it was actually a mine until I checked again on Tuesday evening, at which point it had grown considerably (and had a chalcid wasp investigating it, which I didn’t notice when I took this photo). This is the other likely suspect for the mines on Helianthus in the vegetable garden.


This dazzling caterpillar of the brown hooded owlet moth (Noctuidae: Cucullia convexipennis) was on a little clump of Canada goldenrod by the driveway yesterday morning.


No new leafminers yesterday, but Julia spotted this pair of “bad-wing” moths (Geometridae: Dyspteris abortivaria) resting on a striped maple leaf in the lower nut orchard. Caterpillars of this species eat grape (and Virginia creeper), which is abundant in the immediate vicinity.


We only saw one plump promethea caterpillar on the nearby tuliptree sapling, which, with its few remaining leaves, probably doesn’t mind if the other one was eaten or wandered off to try out another host plant.


This morning a spicebush swallowtail caterpillar was peeking out of one of the folded leaves on the spicebushes we planted next to the garage:


And one more leafminer from this morning, which I found when I went out to cut back the staghorn sumac by the mailbox at the mail lady’s request (it was preventing her from seeing whether our little red flag was up until she’s already zooming past):

Leafminer #143: Caloptilia rhoifoliella (Gracillariidae). The larvae start out making these epidermal linear-blotch mines on the lower leaf surface, and will later live in lopsided rolls at the tips of the leaflets.


And as usual, a few more edible plants to log:

88. Mulberry (Moraceae: Morus ‘Illinois everbearing’) – fruit
89. Dewberry (Rosaceae: Rubus flagellaris) – fruit
90. Self-heal (Lamiaceae: Prunella vulgaris) – leaves & flowers (tea)
91. Zucchini (Cucurbitaceae: Cucurbita pepo) – fruit
92. Potato (Solanaceae: Solanum tuberosum) – tubers
93. Blackberry (Rosaceae: Rubus allegheniensis) – fruit

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Charismatic Megafauna

I interrupt this survey of obscure insects in my yard to bring you… a porcupine chomping on apples.


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The Yard List(s), Part 20

Before I get to the latest additions, I’ve got a few updates on some previous finds. Two exciting (albeit nondescript) flies emerged on Tuesday. One was from the leaf mines on oregano I found by the front stoop on June 20:


He emerged from a moldy leaf, and some of the mold rubbed off on his head and thorax, but unkempt appearance aside, he is the first known North American specimen of Phytomyza origani. Or at least, that’s my assumption; I will be very surprised if Owen Lonsdale reaches a different conclusion when he examines the specimens (another three have emerged over the past few days).

The other exciting fly on Tuesday was this male Ophiomyia from one of the hawkweed stem mines I found on the other side of the front stoop on July 1.


In this genus, males can be recognized from their little Salvador Dalí mustaches as well as by looking at the tip of the abdomen. This fly is either another previously undocumented immigrant from Europe, or an undescribed species, or a named species that has not been reared from hawkweed before. We’ll see what Owen says…

Sawfly #32: On Wednesday I found a larva on a wild red raspberry that was clearly different from #30 on the same host, which had distinct black markings on its head in addition to being much darker overall.


Also on Wednesday, this entedonine eulophid (Chrysocharis, maybe) emerged from the Bohemannia pulverosella leaf mine I collected from the old apple tree on June 21.


Speaking of which, this skinny-waisted entedonine emerged from one of the oregano leaf mines on July 4:


So there are at least two different wasp species parasitizing Phytomyza origani in the little patch of oregano by my front door (I’ve also reared two female eulophines that are likely Pnigalio).

And while we’re on the topic of entedonine eulophids, here’s another one that emerged from a puparium of the hawkweed stem miner on Thursday:


This is why you don’t just collect a single example of a mine and assume what emerges will be the insect that made it! Sometimes there only is one mine though, as with the underside tentiform mine I found on our medlar on June 27, from which this eulophid emerged on Friday:


The host is probably the same as leafminer #115, the Parornix on the hawthorn by the mailbox, whose mines have a similar speckling on the lower surface.  Here’s the one on medlar from which the wasp emerged:


Leafminer #119 & sawfly #33: Schizocerella pilicornis (Argidae).  I saw several mines of this species on purslane while I was picking greens for breakfast in the vegetable garden on Thursday morning.  Adult males of S. pilicornis have fancy antler-like antennae, and one is pictured on the cover of my leafminer book.


Leafminer #120: Bucculatrix pomifoliella (Bucculatricidae).  On Thursday evening I found a single tiny mine of this moth on a black cherry leaf.  As with most Bucculatrix species, after making this mine the larva spends the rest of its life feeding in little patches on the leaf surface.


I also found a single mine of Bucculatrix pomifoliella yesterday on the hawthorn by the mailbox.

Leafminer #121: Coptotriche castaneaeella (Tischeriidae). There were little mines of this moth just getting started on a sapling in the “nut orchard” that is basically a red oak (Quercus rubra) but seemingly with a little black oak (Q. velutina) mixed in.


Earlier on Thursday I had noticed a completed mine of this species along the road by my incessantly ATV-joyriding new neighbor’s house. For whatever reason, Coptotriche castaneaeella decorates the ceiling of its mine with little brown crescents. The contracting silk of its pupal chamber causes the upper epidermis to tear all around it.


Leaf (stem) miner #122: On Friday I found another noteworthy fly mine right by my front door, this time on daisy fleabane (Asteraceae: Erigeron annuus). It was a stem mine made by an agromyzid fly, probably in the genus Ophiomyia, but there isn’t an Ophiomyia recorded from Erigeron. Last year on the other side of the house I found a stem mine on horseweed (Erigeron canadensis, formerly Conyza canadensis) with an empty Ophiomyia puparium in it; this new mine didn’t seem to have a puparium yet, but I’ll keep watching it.


Leafminer #123: Coptotriche citrinipennella (Tischeriidae). Another look at that same blackish red oak sapling revealed several mines of this moth. These mines are always formed along the leaf margin, and silk spun by the larva inside causes the leaf to curl over and conceal much of the mine.


Here’s an adult Coptotriche citrinipennella that just emerged from a similar mine on scarlet oak (Q. coccinea) we collected on July 2 while conducting a leafminer survey in Rhode Island:


I hadn’t really focused my attention on this blackish red oak sapling before, maybe because it’s so close to the ATV tempest that keeps erupting nextdoor lately, but in this moment of calm I looked up and saw an impressive density of leaf cuts made by leaf-rolling weevils.


There is one leaf roll still attached near the middle of the photo.

Sawfly #34: Diprion similis (Diprionidae).  This introduced European species feeds on needles of white pine (Pinaceae: Pinus strobus), and I had found larvae in the woods behind our house a few weeks ago but I’m keeping this list strictly to what I can find in the yard. There are hardly any pine needles near ground level around our yard, but there are some pine trees along the boundary between the “lower nut orchard” and our neighbor, and a larva dropped down from one of these to spin its cocoon on a twig of the blackish red oak sapling.


The other day I showed an example of a “grass sheathminer fly” (Agromyzidae:  Cerodontha dorsalis) mine that was entirely in the sheath of a corn leaf.  I mentioned that on smaller grasses the mine begins as a long track in the leaf blade before entering the sheath; here’s an example on reed canary grass (Poaceae: Phalaris arundinacea), which used to be a dominant feature in the “nut orchard” before we let it become overgrown with shrubs, vines, and small trees.


The “nut orchard” is a little strip of land that was sold to the previous owner of our house by the previous owner of the house nextdoor.  Before that acquisition, I’m guessing the previous owner of our house got a package of assorted tree seedlings from the Arbor Day Foundation or something like that and planted them all together—way too close together—along what was the property boundary at the time.  So there is now a dense clump of trees that don’t naturally grow in this type of soil, and in some cases aren’t native to New England: there is a big nonnative poplar that I haven’t been able to identify; a silver maple; a pin oak; a red pine; a pitch pine (now deceased due to overcrowding); a European larch; and several nonnative spruces (a couple of which we cut down, along with some white pines that may or may not have been planted, to let some more light into our yard).  Most of the silver maple foliage is well out of reach, but looking up at it on Friday I noticed a few characteristic leaf rolls ten feet or so above me:


Leafminer #124: Caloptilia sp. (Gracillariidae).  The rolls were made by one of several maple-feeding species in this genus, which need to be reared to adults to be identified. The larvae form inconspicuous leaf mines and then exit them to feed in lopsided leaf rolls like the ones shown above (below the big one is a smaller one that the same larva made at the tip of another leaf lobe). The little dark smudge below and to the right of the big roll may or may not be the larva’s initial mine.

Leafminer #125: Phyllonorycter trinotella (Gracillariidae).  I did find one leaf mine that was within reach, on a young sprout from the base of the silver maple.  Although there are three eastern Phyllonorycter species that make underside tentiform mines on maples (all of which have been reared from silver maple), this one should be P. trinotella based on its small size.  Naturally, it already has an exit hole made by an emerging parasitoid wasp, so I can’t rear an adult to verify.


Yesterday morning, as I was passing the shadbush we planted next to the garage—on which I found the leaf-rolling sawfly a month ago—I noticed this caterpillar sitting atop some webbing spun over the upper surface of a leaf.


It seemed like an odd thing to do; usually the point of spinning webbing is to hide under it, or to create a leaf shelter to hide in. It’s still sitting there this morning, with denser webbing but no further curling of the leaf.

Anyway, when I stopped for a closer look at the caterpillar, I noticed a bunch of sawfly larvae working on defoliating part of the bush. And looking around the bush a bit more, I found two other species, for a total of four different sawfly species found feeding on this one little bush this season.

Sawfly #35.  Not sure how long these have been there, but they’re certainly making their presence known now.


Nice of them to leave the fruits, at least.


Sawfly #36.  Once I was in a sawfly frame of mind, I noticed a few leaves near the ground with brown patches on them and wondered if they were made by Caliroa larvae feeding on the lower surface.


They sure were!


Although they look much like the ones I found on the aspen sapling in the front yard, I assume they are a different species based on the unrelated host plant.


I also found a single tiny larva of a third species on the underside of one of the leaves at the top of the plant.


At this point I’m not sure whether or not this is different from sawfly #14 (see the bottom of this post), which I found on the little Amelanchier laevis we planted on the other side of the house.  I’ll have to watch and see how it develops.

I spent a good chunk of yesterday afternoon gathering several quarts of black and red raspberries from around the yard, pausing occasionally to collect of photograph another new leaf mine or sawfly larva. This one on blackberry is probably the same as #32 on red raspberry:


After I photographed that one, I noticed that #32 had molted to a prepupa; I dropped it in a jar of soil and it immediately disappeared into it.


While I was at it I got a quick shot of #30, the original red raspberry sawfly, who curls up at the slightest provocation.


Over the next hour I found two larvae on black raspberry:


I put them in the same rearing jar together, but I’m wondering now if I should separate them in case those prominent dark spots on the first one’s prolegs and abdomen are significant. I imagine at least the second one is the same species as the similar ones on blackberry and red raspberry… I sure hope I can rear them to adults so I can get this all sorted out.

While picking berries near a red oak sapling along the south edge of the yard, I found another lovely Coptotriche castaneaeella mine like the one along the road, though a predator apparently tore the larva out of this one before it started making its pupal chamber:


Leafminer #126: Phyllonorycter sp. (Gracillariidae).  There was a single underside mine on that same red oak sapling.


There are many oak-feeding Phyllonorycter species, but based on the way the frass is scattered rather than consolidated into a neat pile at one end, I suspect it is one of the species that gathers up its frass when it’s done feeding and incorporates it into its cocoon. I’m guessing P. basistrigella; hopefully I’ll be able to confirm that later. I don’t remember ever seeing Phyllonorycter mines on oak in my yard before.

Leafminer #127: Calycomyza promissa (Agromyzidae).  There are now numerous mines of this fly on the calico asters (Asteraceae: Symphyotrichum lateriflorum) along the west side of our house.  Here is a nice pair that shows how the mine develops: it starts as a green line leading to a digitate blotch that is centered over the leaf midrib; this blotch expands and becomes puffy and whitish, often obliterating the initial linear portion.  The puparium of this species is formed within the mine, atop a long, narrow pedestal of frass.


I wasn’t the only one who spent the day gathering raspberries. These were on the chipmunk’s favorite perch at the end of a garden wall.


I wished I had a zoom lens handy when I spotted her hanging out with a rabbit on the other side of the vegetable garden.  Look at those cheeks!


Leafminer #128: Agromyza pseudoreptans (Agromyzidae).  I mentioned the other day, when I found the blackish mine of A. reptans on stinging nettle, that the greenish-brown mines of A. pseudoreptans are much more common in my yard.  I’ve been watching some mines on a nettle plant right by the chicken run for a few days; I was pretty sure they were paler than A. reptans, but now they’re far enough along to be sure:


(Stinging nettle plant at left.)

A few more edible plants to log:

83. Basil (Lamiaceae: Ocimum basilicum) – leaves
84. Lowbush blueberry (Ericaceae: Vaccinium pallidum) – fruit
85. American black currant (Grossulariaceae: Ribes americanum) – fruit
86. Gooseberry (Grossulariaceae: some other Ribes species) – fruit
87. Chamomile (Asteraceae: Matricaria chamomilla) – flowers (tea)


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The Yard List(s), Part 19

First, another announcement: This coming Friday morning I’ll be presenting another free webinar; this one is titled “Native Plants as Insect Habitat.” I’ll go through a number of common native New England plants and discuss some of the host-specific bugs that depend on them. I’ve found most of them in my yard, and yes, some of them are leafminers. You can register here.

And speaking of leafminers in my yard, you didn’t think I’d stop counting at 100, did you?

Leafminer #101: Cerodontha dorsalis (Agromyzidae).  Julia spotted this mine on the leaf sheath of a corn stalk (Poaceae: Zea mays) in our garden on Sunday.  I usually stay away from common names for leafminers, but this one has a name I can get behind: the “grass sheathminer.” It feeds on a wide variety of grasses, making long, narrow leaf mines that almost invariably end up in the sheath, where the puparium is formed.  I’ve never seen a mine of this species on corn before, but in this case the entire mine was in the sheath.  (The photo below is rotated so that the ground is to the right.)


Having already found 100 species in my yard when summer had just barely started, I was beginning to wonder if I’d been misremembering in thinking of spring as a relatively slow time for leafminers.  But then I found another 17 species today.  Things seem to be picking up!

Leafminer #102: Cameraria guttifinitella (Gracillariidae), on poison ivy (Anacardiaceae:  Toxicodendron radicans).


Leafminer #103: Ophiomyia kwansonis (Agromyzidae), on daylily (Asphodelaceae:  Hemerocallis fulva).


Leafminer #104: Cerodontha angulata (Agromyzidae), on deertongue grass (Poaceae: Dichanthelium clandestinum).


Leafminer #105: Fenusella nana (Tenthredinidae), on paper birch (Betulaceae: Betula papyrifera).  This is also the 31st type of sawfly larva I’ve found in the yard this year, and if I’m remembering correctly, it’s the sixth type of sawfly larva I’ve found on this individual birch sapling.


Leafminer #106: Phylloporia bistrigella (Incurvariidae), on the same paper birch.  I’ve never seen this species in my yard before (or in Massachusetts, for that matter), nor have I ever found a mine with a larva inside before, so I’ve never reared this species and don’t have a photo of an adult.  I’ll have to watch the birches more closely next spring and early summer.


This species starts by making a long, narrow, linear mine, then forms a blotch, which is the brown, curled portion of the leaf in the above photo.  The large hole to the right of that was cut by the mature larva and the resulting circular leaf piece became its pupal case.  Most leafminers that do this are in the family Heliozelidae, and Annette Braun incorrectly associated these mines with Antispila argentifera when she described that species.

Leafminer #107: one of the several dogwood-feeding Caloptilia species (Gracillariidae), on alternate-leaved dogwood (Cornaceae: Cornus alternifolia).  Alas, the one mine I found had parasitoid exit holes in it, so there’s no hope of rearing it to find out exactly which species it is.  The large holes in the leaf to either side of the mine were made by some other insect.


Leafminer #108: Antispila freemani (Heliozelidae), on alternate-leaved dogwood…


…and on gray-stemmed dogwood (C. racemosa).  As with Phylloporia bistrigella, the larva cuts out an oval pupal case when finished feeding.


Leafminer #109: Coptotriche aenea (Tischeriidae), on black raspberry (Rosaceae: Rubus occidentalis).  I also found mines on red raspberry (R. idaeus) and blackberry (R. allegheniensis).


At this point in my exploration I encountered a very large and handsome toad in the patch of haircap moss (Polytrichum) that grows in the shade of the birch saplings (just by chance, the paper birch sapling is growing right next to a gray birch sapling and a black birch sapling, allowing for easy comparison of host preference among birch-feeding insects).


Leafminer #110: Parornix peregrinaella (Gracillariidae), on sweetfern (Myricaceae:  Comptonia peregrina).  In Darlington’s original description of this species, it’s evident that he mistook the older larva’s feeding shelter (made by using silk to tie down several lobes at the tip of the leaf, in the same way that most other Parornix species make leaf flaps) for its mine, which is a small, underside tentiform blotch.  In the example below, a short initial epidermal linear portion is visible on the lower surface, heading toward the tentiform blotch which is at the base of the leaf.


There seem to be more tiger swallowtails than usual in the yard this year.  Here’s one enjoying some milkweed flowers.


In my leafminer book I mention the existence of possible Phytomyza (Agromyzidae) mines on grass-leaved goldenrod (Asteraceae: Euthamia graminifolia), and this is one of them:


I’m not counting it in my tally because there’s an outside chance that these mines are made by Liriomyza eupatorii, which I’ve already included in the list. I haven’t yet found one with a larva inside, and there are no literature records of Phytomyza from Euthamia—but that doesn’t mean much, since there are no literature records of any other agromyzids from Euthamia other than my own, which document at least five different species using this host.

In the “lower nut orchard” I found a nice example of one of the mysterious “clothesline” egg sacs that are made by an unknown species of Tetragnatha.  I was able to get a DNA barcode from a spiderling from one of these egg sacs, but the species it matched didn’t make sense… more on that some other time, maybe.


Leafminer #111: Coptotriche malifoliella (Tischeriidae), on the old apple tree.


Leafminer #112: Chirosia filicis (Anthomyiidae), on interrupted fern (Osmundaceae:  Osmunda claytoniana).


Leafminer #113: Cameraria ulmella (Gracillariidae), on American elm (Ulmaceae: Ulmus americana).


Leafminer #114: Stigmella scintillans (Nepticulidae), on the hawthorn (Rosaceae:  Crataegus sp.) by the mailbox.  This is one of four Stigmella species recorded from hawthorn in North America, and I had to look this one up in my book.  It’s not a species I’ve found before, so now I have some photos to add to the second edition.


Leafminer #115: Parornix sp. (Gracillariidae), on the same hawthorn.  This is the fourth Parornix on the list, and although I’m not sure exactly what species most of them are, the only other Rosaceae-feeding species I’ve found (on shadbush) is evidently different because it goes straight from leafmining to spinning a cocoon, whereas this one continues feeding in a leaf flap after exiting the mine.  Here’s the underside tentiform mine…


…and here’s the leaf flap.


Leafminer #116: Cycloplasis panicifoliella, a moth of uncertain superfamily placement, on deertongue grass.  I’ve now found two moths, two flies, and two beetles mining leaves of this one grass species in my yard.  Cycloplasis panicifoliella makes a circular cut-out from its finished mine, but unlike Phylloporia and Heliozelidae it uses only the upper epidermis, which it folds in half to make a semicircular pupal case.


Leafminer #117: Phytomyza prava (Agromyzidae), on Canada anemone (Ranunculaceae:  Anemone canadensis).


As with Nemorimyza posticata, the mine of this species appears to be a plain brown blotch, but it turns out to have a fancy herringbone pattern of “toothmarks” if you look at it right.


There were also several of these beautiful Thyris maculata moths (Thyrididae) hanging out on the anemone patch.


I reared this species four years ago from a leaf roll on Clematis virginiana, and I had thought it was a Clematis specialist but evidently it feeds on Anemone too (both plants are in the buttercup family).

Leafminer #118: Pegomya wygodzinskyi (Anthomyiidae), on amaranth (Amaranthaceae: Amaranthus sp.).


And for the last bug of the day, how about this snazzy moth that was resting on the outside of the upstairs bathroom window?  I cranked the window so that I had a clear view of the side of the moth and then took this picture through the screen.  I now wish I had taken out the screen for a sharper image.


I guess it’s a spiny oak-slug (Limacodidae: Euclea delphinii), which has a highly variable wing pattern and an equally dazzling caterpillar:


A few more additions to the list of plants I’ve eaten from my yard this year:

78. Galinsoga (Asteraceae: Galinsoga parviflora) – leaves
79. Shadbush (Rosaceae: Amelanchier sp.) – fruit
80. Highbush blueberry (Ericaceae: Vaccinium corymbosum) – fruit
81. Tomato (Solanaceae: Solanum lycopersicum) – fruit
82. Sweetfern (Myricaceae: Comptonia peregrina) – fruit

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The Yard List(s), Part 18

Seems like every time I lay out a long litany of the latest leafminers from my yard, one gets left out as I’m scanning through my recent photos. Here’s one more from June 28:

Leafminer #94: Agromyza reptans (Agromyzidae), on stinging nettle (Urticaceae: Urtica dioica).  Mines of this fly turn black even as the larva is still feeding, in contrast with the greenish-brown mines of A. pseudoreptans, which are much more common in my yard but haven’t yet made an appearance this year.


Here’s an adult that emerged in the spring of 2018 from a leaf mine I collected the previous October.


On June 27 I found a mine of the weevil Orchestes pallicornis on one of our peach trees (I had first noticed an adult of this species nibbling a black cherry leaf back on May 23 and later photographed one laying eggs).  Peach is not a previously documented host, so I collected the mine to try and rear an adult, but instead I got this male eulophid (probably a Pnigalio) on June 30.


I noticed another four leafminer species for the first time on July 1.

Leafminer #95: Baliosus nervosus (Chrysomelidae). This beetle is known as the “basswood leafminer,” but it feeds on a number of other woody plants, including some of our fruit trees. There are a few mines just getting started on our medlar (Rosaceae: Mespilus germanica—or Crataegus germanica, depending on who you ask).


The holes at the edge of the mine are characteristic and were chewed by the female at the spot where she deposited the egg.  This beetle has never been reared from medlar, nor reported from it other than on this one tree in my yard.  I have collected the mines several times but they have always been parasitized.  I reared this one last August from a hawthorn leaf collected on the other side of the yard:


Leafminer #96: Cremastobombycia solidaginis (Gracillariidae).  A single leaf on a rough-stemmed goldenrod (Asteraceae: Solidago rugosa) by the chicken run had two underside tentiform mines of this moth.


As with Phyllonorycter species, which make similar mines on woody plants, Cremastobombycia larvae pupate within their mines.  Unlike Phyllonorycter, they spin a distinctive spindle-shaped cocoon that is suspended within the mine like a hammock.  The pupa is thrust through one end of the cocoon and through the lower epidermis when the adult emerges.


Leafminer #97: Ophiomya sp. (Agromyzidae).  Well, a stem miner in this case.  I noticed this mine on a yellow hawkweed (Asteraceae: Hieracium praealtum) right by my front door when I was heading out to get some food for some of the sawfly larvae that live on my desk.


This was a surprise, because no North American agromyzid fly is known to mine in hawkweed stems. Well, except for the as yet undetermined species that I’ve reared from native hawkweeds, but this is the first mine I’ve seen on an introduced hawkweed. And maybe more significantly, whereas the mines I’ve found on hawkweed before had a black puparium forming just a slight bump beneath the stem epidermis, in this one (and the others I found over the next 15 minutes of searching my yard) the puparium was concealed beneath a raised “scab” composed of dried latex from the plant.


This is reminiscent of the “scab” formed by an Ophiomyia species that feeds on wild lettuces (Lactuca spp.), first noticed by John van der Linden in Iowa. Once he posted photos on BugGuide and the rest of us knew to look for them, they were soon found by Mike Palmer in Oklahoma, Tracy Feldman in North Carolina, and myself in Maine and Massachusetts (including in my yard). It will be interesting to see if the hawkweed stem miner is the same species.

Leafminer #98: Leucospilapteryx venustella (Gracillariidae).  A little white snakeroot (Asteraceae: Ageratina altissima) that we planted near the chicken house last fall now has numerous underside tentiform mines of this moth.


The mines of this species are much larger than those of Cremastobombycia species on other Asteraceae, and instead of pupating inside them the larvae turn bright red, chew their way out of the mines, and wander off to spin their cocoons somewhere else.


Also on July 1, I found out what those red eggs were that I collected along with the sawfly larvae on the little paper birch sapling next to the house on May 31—the eggs and a young caterpillar are shown near the top of this post.  That caterpillar pupated in a tightly folded leaf margin a while ago, and on July 1 it emerged as an adult “arched hooktip” (Drepanidae: Drepana arcuata):


Here’s the leaf fold pried open to show its pupal skin:


Another emergence on July 1 was this male Liromyza (Agromyzidae):


I collected it as a larva mining a leaf of one of the Jerusalem artichokes (Asteraceae: Helianthus tuberosus) growing along the south side of our house.  I didn’t mention it at the time (June 16) because I suspect it is Liriomyza arctii, which I had already found mining leaves of Heliopsis and Arctium earlier this spring. Liriomyza arctii has never been reared from Helianthus before, though, so now I’ll get to find out if my suspicion is correct.

Yet another adult that emerged on July 1 was this eulophid from a mine of Phytomyza origani on oregano. It’s probably a female Pnigalio; this is the most common parasitoid genus I rear from leafminers.


On July 2, the yellow-spotted paper birch sawfly larva (#23) I collected on June 18 emerged as an adult. It has surpassed Nematus appalachia as the greenest sawfly I have ever seen:


And so this post would have ended, had I not bumped into a few more things this evening right before dinner. When I was picking red raspberries from one of the wild plants I’ve been mowing around right by the clothesline, this sawfly larva fell into my hand—the 30th species for the year (whatever species it may be):


And then while picking greens for dinner in the lower vegetable garden, I found two more leafminers:

Leafminer #99: Pegomya sp. (Anthomyiidae), on lambsquarters (Amaranthaceae: Chenopodium album).  I’ve found two other Pegomya species in the yard so far this year; one on curly dock (Rumex crispus) that is probably P. solennis, and one on spinach that is almost certainly P. hyoscyami.  Although the latter has been reported to mine leaves of lambsquarters, this is clearly a different species because its eggs are completely smooth. It is likely P. atlanis, the species I’ve reared from lambsquarters in my yard in the past; unlike most Pegomya species, it has a single generation per year, and the larvae feeding now won’t emerge as adults until next spring. (There is a tiny mine of Chrysoesthia sexguttella just getting started at far left in the first photo below.)


Leafminer #100: Liriomyza brassicae (Agromyzidae), on nasturtium (Tropaeolaceae: Tropaeolum majus).  In the leaf shown below, the larva switched back and forth between the upper and lower surfaces a couple of times.


And finally, I’ve sampled a few more edible plants from the yard over the past few days:

74. Black raspberry (Rosaceae: Rubus occidentalis) – fruit
75. Sweet goldenrod (Asteraceae: Solidago odora) – leaves
76. Onion (Amaryllidaceae: Allium cepa) – bulb
77. Daylily (Asphodelaceae: Hemerocallis fulva) – flowerbuds, flowers




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The Yard List(s), Part 17

I held off on writing another “yard list” post until I’d met my self-imposed deadline of June 30 for updating the fly chapter of my leafminer book. Now that that’s out of the way, I’ve got some catching up to do… but before I get to that, if you missed my leafminer webinar last week, you can check out the recording here. Also, I’ll be doing a more general presentation on plant-feeding insects (but of course with leafminers sprinkled throughout) on July 10; you can sign up for that here. Okay, here goes…

Back on June 20, I stepped out my front door with a camera or two, planning to contribute a little to a statewide bioblitz that was happening that weekend. The first insect I saw was an agromyzid fly that appeared to be ovipositing on the white vervain (Verbenaceae: Verbena uticifolia) that is growing right against the doorstep. I assumed it would be Calycomyza verbenae, another leafminer for this year’s list, but when I looked more closely I saw that it was a Melanagromyza:


Melanagromyza species are stem borers and seed feeders rather than leafminers, but this was still interesting because the only previous records of Melanagromyza from Verbena in North America are 1) a single male of an apparently undescribed species extracted from a stem of V. scabra in Florida about 50 years ago, and 2) a few specimens John van der Linden reared from V. stricta in Iowa three years ago, which are being described as a new species in a paper that is currently in review. That species feeds in both the stem and in the rachis of the inflorescence.

So if Melanagromyza species aren’t leafminers, why was this one ovipositing in a leaf? She wasn’t. She was “host-feeding”: using her piercing ovipositor to create tiny wounds in the leaves and then drink the juices that oozed from them.


Female agromyzids are pretty well useless taxonomically, so I let her go about her business while I turned my attention to other bugs on and around the stoop. She kept at it for at least another 15 minutes; I usually can’t be bothered with stem-boring insects, but I’ll have to see if I can rear anything from that vervain plant now that I’ve seen a mysterious insect take such a keen interest in it.

There was a fancy iridescent darkling beetle (Tenebrionidae: Tarpela micans) sitting in an otherwise empty bucket on the stoop…


…and a bush katydid nymph (Tettigoniidae: Scudderia), long-legged fly (Dolichopodidae: Condylostylus), and parasitoid wasp resting on jewelweed leaves overhanging the stoop…


…and a paper wasp (Vespidae: Polistes fuscatus) and four-lined plant bug (Miridae: Poecilocapsus lineatus) hiding among the leaves of a mullein plant growing right next to the stoop…


…and then I noticed a brown patch at the edge of a leaf in the big patch of oregano growing next to the stoop.


A leaf mine? Backlighting it confirmed that it was—note the puparium at far left:


I checked my book to see which of the mint-feeding agromyzids this would be. No mention of oregano (Origanum) whatsoever in the Lamiales chapter. So I checked the European leafminer website and found a match: Phytomyza origani. My one hesitation in identifying this mine as such was that the examples on the website all showed a narrow initial linear portion. Hunting around a bit more, I found some like that in my oregano patch:


So not only the 81st leafminer species for the yard list, but a new species for North America! It’s surprising that a “pest” of a common cultivated plant would have gone unnoticed, but I found just a few mines after checking our several large oregano patches, so it seems that this fly has been flying under the radar by existing at very low densities, and by forming mines that often just look like random brown patches at the edges of leaves. Its “damage” to the plants in my yard is certainly negligible; the feeding sign of the four-lined plant bugs is much more conspicuous (but still has no impact on our ability to use the oregano, as far as I’m concerned).

Finally exploring the yard beyond the front stoop, I noticed some Eulophus adults emerging from the “tombstone pupae” I’d found back on the 13th.


I saw several adults of Argyresthia thuiella on the arborvitae hedge, so I can stop feeling guilty about having included this species on the list even though every mine I found with a larva inside turned out to be Coleotechnites thujaella.


You may recall that back on May 28, I found two cocoons on the arborvitae that I believed to belong to Argyresthia aureoargentella.


I collected them with the hope of rearing an adult, but my chances of succeeding were cut in half when this microgastrine braconid emerged from one of them on June 6:


On the evening of June 20, I was surprised to see a large amount of frass in the vial that contained the remaining cocoon. The source turned out to be this sawfly larva:


I’m either extremely lucky that the little piece of arborvitae I collected with that cocoon happened to have a sawfly egg in it, or these larvae are extremely abundant and I’m just very bad at seeing them, because I’ve been scouring the hedge for them ever since I saw this Monoctenus female ovipositing back on May 18, and I have yet to find one.


Whatever the explanation, I’ll count this as the 24th type of sawfly larva found in my yard this year. By June 25, it had developed some longitudinal stripes:


Even though I offered it a fresh sprig of arborvitae, it continued to eat the month-old sprig with the cocoon on it. Here it is with the cocoon the next day:


I discovered yesterday that it had eaten the cocoon. So much for that.

You also may recall that on June 6 I had collected an underside tentiform mine on a paper birch leaf, and the next day the larva had revealed itself to be a Parornix when it emerged from the mine and began using silk to create a marginal leaf fold in which it continued to feed.


Well, we’ll never know which species of Parornix this was, because on June 20 a microgastine braconid emerged from that too. I’m pretty sure the wasp is a Pholetesor species based on its characteristic cocoon that was suspended within the moth larva’s leaf fold.


Leafminer #82: Chirosia flavipennis (Anthomyiidae). On June 21 I noticed this little mine on a bracken fern (Dennstaedtiaceae: Pteridium aquilinum) in the front yard. The white egg  on the underside identifies its maker as a fly in the genus Chirosia, and of the species known to feed on bracken it is most likely to be C. flavipennis. Impressive that its mother managed to find one of the two bracken fronds in our whole yard, which are a byproduct of our having a few years ago transplanted some lowbush blueberry and huckleberry plants from a conservation area in town just before they would have been destroyed to make way for a wheelchair-accessible trail.


Leafminer #83: Phyllonorycter blancardella (Gracillariidae). On the old apple tree by the chicken coop I found a few underside tentiform mines of this moth:


An adult emerged from one of them two days later:


Leafminer #84: Bohemannia pulverosella (Nepticulidae). The apple tree also had a single mine (that I noticed) of this tiny moth, which was only recently discovered in North America. As with Phytomyza origani, I suspect that it has been around for a while and just hasn’t been causing anyone any problems.


Sawfly #25: This one was on a white avens leaf (Rosaceae: Geum canadense) right under the old apple tree. No idea yet who it might be.


Sawfly #26: Caliroa sp. (Tenthredinidae). About a decade ago at the Montague Plains in western Massachusetts, George Leoniak asked me about some larvae that were window-feeding on the underside of a leaf of quaking aspen (Salicaceae: Populus tremuloides). I recognized them as Caliroa “slug” sawflies, but no Caliroa is known to feed on Populus. I’ve been regretting ever since that I didn’t collect those larvae and try to rear them; I’ve checked a lot of aspen leaves and have never found any further evidence of their existence… until ten days ago, when I noticed patches like this on the little quaking aspen sapling in our “lower nut orchard.”


Flipping the leaves over, I found Caliroa exuviae on the lower surface, but alas, there were no actual larvae remaining.


Nearby I spotted a well-concealed red-eyed vireo nest in a grapevine. I’m honored that this bird flew all the way from the Amazon to weave this little work of art in my yard.


Sawfly #27: These larvae were feasting on a leaf of one of our cultivated hazelnuts. They are tenthredinids rather than the big Arge species that shows up on our hazelnuts every year, but I’m not sure exactly what they are.


These larvae have now all finished feeding and spun cocoons. There was one straggler left on June 29:


Still in the “lower nut orchard,” I found a couple of these snazzy sawfly larvae on late goldenrod (Asteraceae: Solidago gigantea):


I won’t count these as a new type, because the tiny, plain larva I found on Canada goldenrod two weeks ago (shown at the end of this post) now looks exactly like this.

Leafminer #85: Bucculatrix angustata (Bucculatricidae). These little blotches on a leaf of calico aster (Asteraceae: Symphyotrichum lateriflorum) were made by a larva of this moth after exiting its initial linear mine.


On June 22, I was somewhat disappointed to see that an ichneumon wasp had emerged from a sumac twig into which one of the black-headed lady fern sawfly larvae had bored a week or so earlier. Then I was excited to realize that it was actually a sawfly that just looked like an ichneumonid:


It appears to be Thrinax albidopicta, which has been associated with sensitive fern (Onoclea sensibilis) but not lady fern (Athyrium angustum) as far as I know. Five adults of the pussy willow sawflies emerged on the same day; I’m still not sure exactly what they are.


When I checked on June 26, I found larvae of the second generation feeding away on the same pussy willow:


On June 23, I checked the wee bigtooth aspen sapling in the front yard, from which I had collected five nematine sawfly larvae on May 31, and this time I found five Caliroa “slugs” on it—presumably the same species that had already come and gone on the quaking aspen sapling.


Feeding on the undersides of leaves was a good strategy for these larvae, given that the sapling was in full sun in the middle of a string of 90°F days when I found them. While I was photographing them, a tree swallow was relentlessly dive-bombing me, as he had taken to doing once there were nestlings in his box.

I got some more photos of these larvae indoors a few days later. At the right angle, you can see that there are little faces and legs hidden under those slimy bodies:


Leafminer #86: Mantura floridana (Chrysomelidae).  I found a few vacated mines of this beetle in a clump of yellow wood-sorrel (Oxalidaceae: Oxalis stricta) along the road. The “normal” hosts of M. floridana are plants in the buckwheat family (Polygonaceae), which like wood-sorrel have a sour flavor due to the presence of oxalic acid. This is the first time I’ve seen them using Oxalis in New England.


Also on June 23, this ichneumonid (Gelis, or so) emerged from the Coleophora pruniella case I had found on a grape leaf on June 9.


On June 26 I found two sawfly larvae eating leaves of our cultivated strawberries. I suspect they’re the same species that I found on white avens, since at least one of those two had a head pattern like this at one point.


On the other hand, I won’t be surprised to learn that they are two different species, because there was a definite behavioral difference. Whereas both of the avens larvae just sat there dopily while I photographed and collected them, both of the strawberry larvae quickly curled up and dropped to the ground as soon as I bent down to look at them.

A visit to our largest red oak sapling (the one that had all the Acordulecera larvae back at the end of May) added two new leaf-mining moths to the list.

Leafminer #87: Stigmella quercipulchella (Nepticulidae).  This particular larva was dead for unknown reasons, but I saw several healthy yellow larvae feeding away during a walk in the woods yesterday.


Leafminer #88: Bucculatrix sp. (Bucculatricidae).  No telling which of the many oak-feeding species made these tiny mines, but clearly something other than the two aster-feeding species I’ve listed so far this year.


There were numerous Bucculatrix mines and I spent a little while unsuccessfully looking for older larvae feeding exposed on the undersides of the leaves. I did see some of their feeding sign and empty molting cocoons though.


A little black cherry sapling added another two moth species.

Leafminer #89: Stigmella prunifoliella (Nepticulidae).  The larva that made this mine was extracted by an ant or some other predator when it was nearly mature.


Leafminer #90: ?Phyllonorycter crataegella (Gracillariidae).  The much smaller size distinguishes this underside tentiform mine from that of P. propinquinella, the other possibility on black cherry—unless it turns out to be a Parornix.


Leafminer #91: Phyllocnistis vitegenella (Gracillariidae).  When I waded into the little wild area between the front yard and the “upper nut orchard” to pull up a bittersweet vine, I spotted the first “snail trail” mine of this species on a riverbank grape leaf.


Sawfly #28: Pristiphora appendiculata (Tenthredinidae).  I had listed this as sawfly #15 back on June 15, but I corrected that a few days later when I realized the hatchlings I collected were developing into Nematus ribesii.  On June 26, I found an actual P. appendiculata larva on the same red currant bush.


There happened to be a Nematus ribesii larva munching on the other side of the same leaf.


Two days later I noticed the little buggers defoliating our gooseberry bush.


On June 14 I wrote about the paper birch sawfly larva that appeared in a rearing jar at the same time that 29 adults were emerging from the leaves collected on May 31. It didn’t have a pink butt like all the larvae I’d originally collected, but then later it did have a pink butt but also had longitudinal stripes and was much larger than the original larvae. Well, that larva emerged as an adult on June 26.


It looks an awful lot like all the others, but as with the larva it is much larger. I look forward to hearing what Dave Smith has to say when he examines the specimens.

Also on June 26, a microgastrine braconid appeared in the jar of pin cherry leaves I’d collected on June 17 with the hope of confirming that the mines and rolls on them were the work of Caloptilia invariabilis.


Sawfly #29: Waldheimia carbonaria (Tenthredinidae).  On June 27 I noticed some tattered leaves on an evening primrose (Onagraceae: Oenothera biennis) growing along the front of the house, and found these larvae to be the cause:


I first noticed larvae of this species in my yard in September 2016, and had adults emerge the following spring:


Leafminer #92: Liriomyza asclepiadis (Agromyzidae).  These beloved milkweed specialists finally made their appearance in my yard on June 28.


On June 29 one of the plain-headed lady fern larvae emerged as an adult. It turns out to be Aneugmenus flavipes, a species previously associated with bracken fern.


The same day, this Parornix emerged from one of the smooth shadbush (Amelanchier laevis) leaves I’d collected with sawfly larvae on June 12.


A look at Dietz’s (1907) key to this genus reveals that… yup, it’s a Parornix.  Maybe quadripunctella?  That species does feed on shadbush; depending on how I interpret the key, I could also land on strobivorella or vicinella, but the former is supposed to feed on mountain-ash (Sorbus) and the latter on birch (Betula).

Leafminer #93: Phyllocnistis liriodendronella (Gracillariidae).  The much needed rain over the past several days has kept me from looking for new leafminers, but I noticed the initial spirals of this species on the magnolia by the front stoop yesterday morning.


Y’all can keep calling this Phyllocnistis magnoliella for now if you want, but Don Davis and I have decided to synonymize that name under P. liriodendronella (the tuliptree miner), for reasons I won’t go into here.

Also, yesterday the adult Marmara fraxinicola emerged from the white ash bark mine I collected back on May 22:


And finally, the latest additions to the list of plants I’ve eaten in the yard this year. The drought has deprived us of some of the tree fruits we were looking forward to harvesting later in the season, but the shrubs have held onto their fruits just fine.

68. Wild strawberry (Rosaceae: Fragaria virginiana) – fruit
69. Purslane (Portulacaceae: Portulaca oleracea) – leaves & stems
70. Red currant (Grossulariaceae: Ribes rubrum) – fruit
71. White mulberry (Moraceae: Morus alba) – fruit
72. Goumi (Elaeagnaceae: Elaeagnus multiflora) – fruit
73. Red raspberry (Rosaceae: Rubus idaeus) – fruit

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Free leafminer webinar at 7PM EST!

In case you don’t follow me on Twitter or Facebook, and don’t get the occasional emails Noah Charney and I send out from our “Northern Naturalists” account, and haven’t subscribed to my leafminer bookand haven’t heard enough about leafminers from me through this blog: Five hours from now I’ll be presenting a free hour-long webinar about leafminers, hosted by my local land trust but open to all, wherever you may be. The link to register for it is here.

My apologies if this is the first you’re hearing about it; I don’t usually make announcements like this on my blog, but I realize it’s only been on my calendar for a few days so even people who check there regularly may have missed it.



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The Yard List(s), Part 16

Before I launch into listing the latest leafminers to appear in my yard, I have a request related to these mines I found on a grape leaf back on June 10:


Linear mines on grape leaves are made by larvae of moths in the genus Phyllocnistis. The short version is, I’m hoping folks in the western US will keep an eye out for these and send me some. If you find any, please email me (

The longer version is, when I was working with Don Davis on the Gracillariidae section of the Annotated taxonomic checklist of the Lepidoptera of North America, North of Mexico that will be published later this year, I learned that Don was planning on synonymizing Phyllocnistis vitifoliella with P. vitegenella because the adults of these two grape-feeding species don’t seem to be distinguishable. However, I am convinced not only that they are two distinct species, but also that there is a third, undescribed species in the western US. I won’t go into all the evidence right now, but the hypothesized species are easy to distinguish by their leaf mines. Phyllocnistis vitifoliella makes distinct mines that are nearly filled with frass, as in the photo above. I believe it only occurs in eastern North America (and has been introduced in Europe, where it is being referred to as P. vitegenella).

Phyllocnistis vitegenella makes an indistinct, entirely epidermal mine resembling a snail trail, with no visible frass. It occurs throughout North America.


The alleged third species forms a distinct mine with a narrow, central frass line. Mines have been found in California, Arizona, Utah, and Colorado, but no adults have been reared from them as far as I know. Both this species and P. vitifoliella are occasionally found on Virginia creeper (Parthenocissus).


So I’m hoping for western material of grape and Virginia creeper Phyllocnistis mines, especially those of the third type (but others could be useful too, and I’d be interested to know if anyone finds mines of the first type in the West). I have an opportunity to do some DNA analysis on these, and I don’t necessarily need reared adults for that (although those would be a nice bonus). Larvae or pupae would do just fine, even dead, dry ones.

The leaf in my first photo shows three mines, and I preserved one of the larvae for DNA analysis. It will be interesting to see whether the DNA obtained from that larva belongs to Phyllocnistis or something else, because I suspect all three of the larvae were being slowly devoured from within. When I collected the leaf on June 11, none of the larvae had moved since the previous day. This is the one I preserved:


The remaining two larvae still hadn’t mined any further as of yesterday, and I finally got around to taking a closer look. This backlit view of the end of a mine shows a parasitoid larva (left of center) and hardly any trace of the Phyllocnistis larva.


The Phyllocnistis larva has likewise been obliterated in the end of the other mine, and in this case the parasitoid larva has pupated.


The dots along either side of the pupa are meconial pillars. Eulophid wasp larvae save up all of their poop until they’re ready to pupate. Some then deposit it all in a single pile, as with the Eulophus pupae shown in this post. Some of the ones that specialize in parasitizing leafminers, however, cleverly arrange it in little pillars attached to the floor and ceiling of the mine, which protects them from possible collapsing of the mine as the affected portion of the leaf dries and crumples.

With that out of the way, it’s time to see where my leafminer tally for the yard stands as spring comes to a close.

Leafminer #74: Liriomyza ptarmicae (Agromyzidae). I found this mine on Wednesday (June 17) right next to the Ophiomyia maura mine on goldenrod, but for whatever reason I forgot to include it in my previous post. It was on mugwort/wormwood (Asteraceae: Artemisia ?vulgaris).


This is the fly shown on the cover of Leafminers of North Americaa female ovipositing in Artemisia ludoviciana ‘Silver King’ in my mother’s garden:


After spending a considerable amount of time scouring the yard for new leaf mines on Wednesday, I don’t know what to make of the fact that I found four more yesterday evening in the space of five minutes, on my way to pick some lettuce for dinner.

Leafminer #75: Agromyza parca (Agromyzidae).  There were a few young mines of this species on deertongue grass (Poaceae: Dichanthelium clandestinum) in the front yard.  Agromyza mines on grasses often begin with a cluster of punctures made by the female’s ovipositor.  Eggs are laid in some of these, but most are made for “host-feeding” (when the female drinks the fluid that bubbles out of the puncture in the leaf).


Although four species of Agromyza are now known to feed on Dichanthelium spp., A. parca is the one I’ve reared in my yard.


Leafminer #76: Ophiomyia parda (Agromyzidae), on heart-leaved aster (Asteraceae: Symphyotrichum cordifolium).


This is another species whose type specimen came from my front yard. Its name (from the Latin name for leopard) refers to the distinctive widely spaced spots of frass along the length of the mine.


Leafminer #77: Amauromyza flavifrons (Agromyzidae), on mouse-ear chickweed (Caryophyllaceae: Cerastium fontanum).


This fly uses a number of different hosts in the pink family. It is known to feed on mouse-ear chickweed in Europe, but I think this is the first record of it on Cerastium in North America.


Leafminer #78: Liriomyza taraxaci (Agromyzidae).  This one was on the lettuce itself!


I don’t remember ever seeing a leaf mine on cultivated lettuce (Lactuca sativa) before. In the past I’ve reared Liriomyza taraxaci from leaves of dandelion (Taraxacum officinale) and tall blue lettuce (Lactuca biennis) in my yard. Or at least what we’re calling L. taraxaci for now; Owen Lonsdale says this is a species complex that he hasn’t been able to sort out yet. The mines on dandelion and tall blue lettuce are pretty different; not surprisingly, this one on cultivated lettuce is similar to the ones on tall blue lettuce.

Leafminer #79: Cerodontha incisa (Agromyzidae).  I spotted this one this morning on timothy grass (Poaceae: Phleum pratense) while mowing the narrow strip of lawn between our house and the untamed meadow / orchard / vegetable garden that is our front yard.


This species has a fancy metallic puparium, which is formed inside the mine. There are often several larvae feeding together.


Leafminer #80: Plutella xylostella (Plutellidae).  This diamondback moth cocoon was on the underside of a kale leaf that was picked for today’s lunch:


As illustrated in this post from three years ago, larvae of the diamondback moth are briefly leafminers before switching to feeding externally. As also shown in that post, the above cocoon has a cocoon of an ichneumon wasp inside it.

I think of spring as not a very productive time for leafminers, so I’m pleasantly surprised to have found 80 species in my yard this season. How many more will summer bring?

One more update on a previous post: back on May 29, I showed a stem mine of Marmara elotella (Gracillariidae) on our “Dave’s Delight” apple tree. Today the adult emerged, and since my usual white background wouldn’t do for a predominantly white moth, it was kind enough to pose on an apple leaf. It sat perfectly still for many minutes, except for its antennae, which were twirling constantly.


This may be the first time this species has been photographed alive, unless there are some photos out there that have been determined only to genus. Given that there are dozens of undescribed Marmara species, it’s not a good idea to try to put names on adults found at lights or otherwise not associated with a host plant.

And before I sign off, let’s see where the list of plants I’ve eaten from my yard stands at the end of spring:

62. Sugar snap peas (Fabaceae: Pisum sativum) – fruits
63. Amaranth (Amaranthaceae: Amaranthus sp.) – leaves
64. Mallow (Malvaceae: Malva sp.) – leaves
65. Yellow salsify (Asteraceae: Tragopogon dubius) – leaves
66. Nasturtium (Tropaeolaceae: Tropaeolum majus) – leaves
67. Chard (Amaranthaceae: Beta vulgaris) – leaves

We’ve had very little rain over the past few weeks, and I’m constantly amazed that all these plants that are feeding me and Julia, the bugs, the rabbits and voles and chipmunks, and everyone else in my yard are made of nothing but sunlight, air, the powdery, bone-dry soil, and whatever water they can glean from it.

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The Yard List(s), Part 15

Lots of new things to report, as usual… First, I forgot to mention this leaf mine I found on Saturday (June 13) on the old apple tree by the chicken coop:


This is so far an entirely epidermal mine: the larva is slashing open epidermal cells and drinking the fluid contents, without consuming any tissue. The “sap-feeding” early instars of gracillariid moth larvae have entirely different mouthparts from the older instars, and you can sort of see them in this backlit view:


According to the key I wrote for apple leaf mines, this should be Callisto denticulella, but I’ve never been able to rear this species to confirm. I’ll do my best this year. In any case, it’s leafminer #64 for this spring’s yard list.

Remember those pink-tipped sawfly larvae I found on a little paper birch sapling right next to my house, back in Part 10?


I mentioned that they had started to spin cocoons by June 4. Well, on Sunday morning (June 14), the adults were already starting to emerge:


As of today, 29 adults have emerged. I didn’t think I had collected quite that many! Also, a few other things that I hadn’t noticed before appeared in that jar on Sunday. One was this sawfly larva, which was quietly munching away on one of the remaining leaf fragments at the bottom of the jar:


It doesn’t have a pink-tipped abdomen, and it has a central stripe on the top of its head, so it’s a different species from the larvae I had knowingly collected back on May 31. It must been an unnoticed egg at the time I collected the leaves—and one that somehow escaped being devoured by the 29+ larvae I collected.

It also seems to be a different species from this one I found on the paper birch sapling at the southeast corner of my yard on June 5, with the distinct stripe behind its eye:


So we’ll call it sawfly #17 for the yard list.

Just to confuse things, as of yesterday it did have a pink butt, but I still think it’s a different species due to the dorsal stripes and head markings. I also think it’s quite a bit larger than the original pink-butt larvae ever got.


The other things that appeared in the jar on Sunday did not come as a surprise—several small caterpillars like this one:


When I was collecting those pink-tipped sawfly larvae back on May 31, I had noticed this group of three eggs on one of the leaves they were eating:


I was curious what kind of moth they belonged to, but not quite curious enough to put them in their own vial, so I just put them in with all the sawfly larvae. I know for certain that the caterpillars came from these eggs, because I later found an identical group of three eggs on a black birch sapling elsewhere in my yard, which I did put in an isolated vial, and identical caterpillars hatched from those.

I moved this new birch sawfly larva and these caterpillars to their own jars, and I went to get fresh paper birch leaves to feed them—from that same sapling where I collected the eye-stripe larva on June 5, and where I found the leaf-mining sawflies (Fenusa pumila) a few days ago. When I reached that sapling, I was greeted by sawfly #18—and the fifth type of sawfly larva I’ve found on paper birch this spring:


I came back with a different lens the next day to get this close-up:


And here’s how they look today:


I think these are larvae of the dusky birch sawfly, which most people still call Craesus latitarsus (Tenthredinidae) although Nematus latitarsus is technically the correct name at the moment. I haven’t reared that species but the adult looks like this:


I wasn’t the only one who showed up to check on them today.


These were the best I could do with the wind and with essentially no depth of field. It’s an ichneumon wasp looking to parasitize some sawfly larvae; I ran these photos by Gavin Broad and he says it belongs to the tribe Exenterini of subfamily Tryphoninae. I have some photos of a sawfly larva with a tryphonine egg on it here.

Leafminer #65: Pegomya hyoscyami (Anthomyiidae).  Sunday evening while we were picking greens for dinner, Julia noticed mines of this species just getting started on a spinach leaf.


As with other Anthomyiidae, the mines begin with white eggs attached to the lower leaf surface…


…which are best appreciated under high magnification:


These were some unhatched eggs on a neighboring leaf. When we find eggs or young larvae, we just make sure to eat the leaves soon; once the larvae get bigger and are making a mess of the leaves, they go to the chickens. Both Pegomya betae and P. hyoscyami mine leaves of spinach and I don’t know of a way to distinguish their mines, but I’m assuming we have the latter since that’s the species I’ve reared from our spinach in the past.


When I got the macro lens for those eggs, I couldn’t resist getting a portrait of this pygmy grasshopper that was hanging out under the spinach:


Leafminer #66: Scaptomyza flava (Drosophilidae).  A single leaf on one of the sugar snap peas had larvae of this fly mining it:


This species mostly feeds on mustards (Brassicaceae), but it occasionally dabbles in other herbaceous plants. Here’s an adult I reared from tower mustard (Turritis glabra) growing right next to the vegetable garden six years ago:


I found several more S. flava mines on kale leaves this evening:


Sawfly #19: On Monday morning while pulling up a multiflora rose stem that had popped up among the jewelweed at the edge of the leach field, I noticed some nibbling on the branches of some field horsetails (Equisetaceae: Equisetum arvense). After staring for a couple of minutes I found the well-camouflaged sawfly larvae that were responsible. They presumably belong to a species of Dolerus.


Leafminer #67: Liriomyza equiseti (Agromyzidae). There was also a single mine of this fly on one of the horsetails.


This species is known to occur throughout Canada and in Europe, but the only US state where it has been documented is California. I have a puparium from a similar mine I found in the ditch across the road the other day, so maybe I’ll be able to rear an adult and add Massachusetts to its confirmed distribution.

Earlier this spring we were given a carload of leftover native plants from a local nursery, and we planted some of the wetland species in spots in the seepy woods behind our house that we had recently disturbed by pulling up multiflora rose, Japanese barberry, Asiatic bittersweet, etc.  One of these plants was a swamp milkweed, which on Monday I noticed had many mines of Liriomyza asclepiadis on it.  On Monday evening I checked some of the common milkweed in our yard to see if I could add that species to the yard list, but no sign of it there yet.  I did, however, find another milkweed associate that I’d failed to include in my list of non-monarch insects that depend on milkweed:


Aphids. It turns out there are multiple aphid species associated with milkweed, besides the well-known bright yellow oleander aphids (Aphis nerii) that are introduced from the Mediterranean. Looks like these might be Aphis asclepiadis.

Aphids get a bad rap. I think they’re kind of charming.


Some ants were attending to the aphids on an adjacent leaf.


These pink leafhoppers (Cicadellidae: Graphocephala gothica) were on several of the milkweed plants. I see them on milkweed regularly, so I’m convinced they feed on it, but I haven’t found any information about what its host plants are supposed to be.


In my previous post I said the sawfly larvae on the red currant bush were Pristiphora appendiculata, because that’s the species I’ve found in past years. But on Monday when I checked the bush again, I found some older larvae and realized they are in fact the imported currantworm, Nematus ribesii. Some photos here show that that species inserts eggs along the veins just like the ones I found in association with the young larvae a few days ago.


The original larvae I collected have now developed distinct dark spots; here are two that have reached an impasse:


Leafminer #68, and sawfly #20: Fenella nigrita (Tenthredinidae).  Julia and I first met this species in September 2012 in the Black Hills of South Dakota, and I think the only other time I’ve found it was at the Berkshire BioBlitz in September 2018.  So I was excited to see these mines on common cinquefoil (Rosaceae: Potentilla simplex) along the south side of the house yesterday morning while we were planting our latest acquisitions there. Admittedly they’re not much to look at:


A backlit view confirmed the presence of characteristic sawfly fecal pellets, and that the larvae had already exited the mines.


Here’s one of the adults from South Dakota:


The problem with offering sawfly larvae sumac stems rather than wine corks to bore into to pupate is that I’m not 100% sure whether this wasp that emerged yesterday was a parasitoid of that first lady fern sawfly larva I collected on June 6, or emerged from some other insect that was already in the other sumac stem I had placed in the jar. Eventually I’ll cut open both stems and hopefully sort that out.


Another of yesterday’s emergences was this Cosmopterix gemmiferella from the deertongue grass mine I collected in the backyard on May 29:


Today’s slow stroll around the yard added a few more species to the list.

Leafminer #69, and sawfly #21: Metallus capitalis (Tenthredinidae).  I found a single larva of this species mining a leaf of red raspberry (Rosaceae: Rubus idaeus) in the nut orchard.


This species (like Fenella nigrita) has two generations per year; I collected mines in my yard on September 30, 2015, and this adult emerged the following spring:


Leafminer #70: Caloptilia invariabilis (Gracillariidae).  I found leaf rolls associated with small, underside tentiform mines on a pin cherry (Rosaceae: Prunus pensylvanica) right next to that raspberry, and I believe they are the work of this species rather than C. serotinella, which I found on a black cherry sapling in my yard earlier this spring.


I reared this adult from similar mines and rolls I found just outside the classroom at the Eagle Hill Institute where I taught my leafminer seminar last summer:


Sawfly #22: Acordulecera sp. (Pergidae).  I found these larvae munching on butternut leaves (Juglandaceae: Juglans cinerea) right next to the red oak where I found Acordulecera larvae on May 29. They look pretty similar, but I suspect they are a different species based on the different timing, different host, and much paler legs.


Sawfly #23: When I went to check on those gregarious larvae on the paper birch sapling today, I found yet another sawfly species—the sixth for paper birch and the fourth for that individual sapling. The yellow spots along the back make this one obviously distinct from all the others.


Leafminer #71: Phytomyza erigeronis (Agromyzidae).  This one completes the expected trio of daisy fleabane (Asteraceae: Erigeron annuus) leafminers for the yard.


It’s the first species to turn up this spring whose type locality is my yard. Here’s one of the paratypes:


Leafminer #72: Ophiomyia maura (Agromyzidae).  Yet another goldenrod leafminer. This species makes a very long, narrow mine, forming its puparium within the leaf but hidden on the lower surface.


Leafminer #73: Phytomyza plantaginis (Agromyzidae).  This one was on narrow-leaved plantain (Plantaginaceae: Plantago lanceolata).


This mine was mostly on the lower surface of a leaf that had curled so that the lower surface was on top. When almost done mining, the larva switched to the upper (= lower) surface, forming its puparium at the end of the mine.


The very narrow, white mine is distinctly different from the irregular, brownish mines of the plantain flea beetle (Chrysomelidae: Dibolia borealis) that are now abundant on broad-leaved plantain (P. major) in my yard.


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The Yard List(s), Part 14

A couple of weeks ago, I ended a post by mentioning that I’d just cooked up some milkweed shoots, adding:

…don’t worry, there is plenty left for the monarchs, and the milkweed tussock moths, and the large and small milkweed bugs, and the milkweed long-horned beetles, and the milkweed weevils, and the milkweed leaf-mining flies—all of which are equally deserving of our affection and it drives me nuts when people want to kill or remove any non-monarch organism they find on their milkweed plants. If you simply refrain from mowing your lawn, you will soon have more than enough milkweed to suit everybody’s needs. We got enough from weeding a few strawberry and asparagus patches yesterday to provide the main vegetable for last night’s stir fry and this morning’s omelet, and new shoots keep popping up faster than we can pick them.

I don’t know that anyone read that far besides the two people who commented, which is fine; who has time to read blogs these days? I sure don’t. Anyway, not long after that, I was excited to see one of these lovely creatures in my yard:

IMG_5448 (2)

A swamp milkweed leaf beetle (Chrysomelidae: Labidomera clivicollis). I encounter these infrequently enough that I forgot to include them in the above list of insects that depend on milkweed.

I bring this up now because last night I was sent two photos of one of these beetles, accompanied by the following note:

Hi, Charley these were on my swamp milkweed mating last week. They are larger than ladybugs. I left them there but a few days later, I noticed the tips of some of the swamp milkweed stems looked stressed and not good. When I unfurled the contracted leaf, I found one of these inside. They were not around last year. I’m thinking they are not beneficial. Do you know these bugs?

I would love it if we could all stop using the word “beneficial” to describe other organisms—the implication being that anything that we do not deem to be “beneficial” is “detrimental” and must be destroyed. We really need to stop thinking that way, and recognize that we are all part of a complex ecosystem, and we need to start acting accordingly. Sure, there are a few insects that compete directly with us for food, and then there are the 99.99% that do not. If the former are causing us problems, it is a sign that we need to diversify our diets and modify our agricultural practices. But this exchange was not about an agricultural pest, so I won’t elaborate on that just now. Here is how I replied:

This is, believe it or not, called a swamp milkweed leaf beetle. Not sure what you mean by “beneficial”; they are less damaging to milkweed than monarchs are, and aren’t related to the stressed stems you observed.

She hadn’t mentioned monarchs, but I knew from past experience that that’s what this was about. (In case our anonymous correspondent is reading this, this is not directed at you personally; I encounter this constantly, which is why I previously wrote the paragraph that I’ve copied and pasted at the top of this post. Our exchange simply suggested to me that I need to lay out my thoughts on this subject more clearly, rather than alluding to them at the bottom of a long post… or in terse, passive-aggressive replies to innocent email inquiries.)

Her response this morning:

Thank you- I think of ladybugs as beneficial because they eat aphids and non desireable bugs. I will look up the swamp milkweed leaf beatle and decide whether to drown , Again this morning it is within the damaged stalk and no other parts of the plant look stressed at all.I just took a photo and will send. Thanks for prompt ID!

My reply:

These beetles don’t do anything but nibble leaves of milkweed. There is certainly no reason to drown them.

And hers:

After reading comments on this beetle in Dave’s Garden, I am calling it a non-beneficial pest which would desecrate my plant and deprive the monarchs from the plant I provided for them. Last year I had as many as 12 monarch caterpillars at one time! I eradicated the oleander aphids when I first saw them last year and now will attempt the same with these beetles, treating them the same treatment I give japanese beetles-drowning in soapy water. Thank you again, ______

With this reply, she sent the photo, and I concede that the beetle may well have caused the wilting by nibbling the stem in a way that girdled it. And some of the accounts at Dave’s Garden do sound pretty damning. But it’s hard to judge without seeing the plants in context—I would bet that these tales of woe involve trying to grow small numbers of plants in habitat that is suboptimal for them, making them less resilient than they would be in their natural habitat. I have spent many years surveying wetlands where swamp milkweed occurs naturally, and I’ve never witnessed these beetles causing anything like the devastation these people are describing.

And in any case, it’s a swamp milkweed leaf beetle; doesn’t it have a right to do whatever it needs to do to a swamp milkweed plant? How is it that with the thousands of insect-hostplant relationships out there, so many people care only about milkweed and just one of the insects that depend on it? I love monarchs, don’t get me wrong, but the fixation on this one species at the expense of so many others is causing real harm—including to monarchs. (A couple of years ago I bought a sheet of “Protect Pollinators” postage stamps, and when I looked at them I discovered that the five images they depicted comprised three different photos of monarchs and two of European honey bees. Way to showcase the diversity of our native pollinators, guys.)

How about instead of asking “is it a good bug or a bad bug?” every time we encounter an unfamiliar species, we try asking ourselves: “Am I beneficial?” Of course, this is just as silly a question as asking whether an insect is beneficial (if you click on the above link you’ll see how a much maligned insect creates a valuable resource for numerous other species… and by the way, that magnolia bush is still flourishing). Every action we take will benefit some beings (human and nonhuman) at the expense of others. So we should carefully consider our actions. How is it beneficial to attempt to annihilate every creature that happens to feed on the same plant as this one species of butterfly? Or to entirely ignore the needs of the tens of thousands of other insect species with which we share this continent?

I have put zero effort into attending to the well-being of my local monarchs. I simply let the milkweed do its thing, and eat the shoots that pop up where I’m trying to grow something else. Here’s one patch of the former lawn right next to my driveway, as it looks today:


I saw the first monarch come fluttering through this patch a few days ago. I was happy to see it, and yet somehow the thought of destroying other living things to make way for its offspring never crossed my mind. I did, however, fill a colander with clusters of flower buds to cook up for lunch shortly before taking this photo. Plenty of milkweed for everyone.

Now then, before I was compelled to go on this rant, I was in the process of cataloging all the leafminers and sawfly larvae I’m finding in my yard this season. Two groups of insects that, like monarchs, are fascinating and highly host-specific. Unlike monarchs, these are insects that hardly anyone knows anything about, which is why I’m going to the trouble to share what I’m finding with you all.

Leafminer #56: Calycomyza solidaginis (Agromyzidae). This fly is a specialist on goldenrods (Asteraceae: Solidago), as its name implies.


At first glance, the mine is similar to that of Nemorimyza posticata (see yesterday’s post), but it lacks the herringbone pattern of “toothmarks” and has a relatively clean, whitish appearance due to the larva saving up most of its frass until it’s ready to pupate. And the puparium is formed inside the mine (instead of outside, as in N. posticata), glued to the floor by a big lump of frass.


I wrote about this species once before, and showed a close-up of the curved exit slit in the upper surface of the mine. As you’ll see in the last paragraph there, I didn’t realize at the time that the larva makes that exit slit before pupating, so that the adult will have a way to get out.


Leafminer #57: Phytomyza agromyzina (Agromyzidae). This fly forms entirely linear mines in dogwoods; in this case, gray-stemmed / red-panicled dogwood (Cornaceae: Cornus racemosa). I found a single example yesterday on a small plant that recently sprung up in the area we optimistically refer to as the “nut orchard,” although to date it has yielded us a total of one hazelnut.


In the meantime, in the wild spaces between the young hazelnut, chestnut, butternut, and walnut trees and shrubs we’ve planted, the birds have been doing their own planting, so while we wait for our first big nut harvest, there are pokeweed shoots, tender sumac branchlets (which we used as a sushi ingredient yesterday), wild strawberries, red currants, elderberries, raspberries, and blackberries for us to eat, and dogwood leaves for Phytomyza agromyzina to eat.


Speaking of hazelnuts, I noticed yesterday that a leaf-rolling weevil (Attelabidae) had done its thing on one of the hazelnut leaves:


A week or so ago I found one of these on one of the Chinese chestnuts. I had never seen weevil rolls on either plant before; I most often see them on oaks, and I wrote about sumac and alder leaf-rolling weevils here. I suspect the species responsible in this case is Attelabus bipustulatus, which is the one I’ve seen on oak before and the one I saw working on cutting an alder leaf to roll when I visited the local beaver pond the day before yesterday:


And speaking of blackberries (Rosaceae: Rubus allegheniensis), I noticed yesterday that one of the old dead canes is currently serving as a nest site for a small carpenter bee (Apidae: Ceratina)—you can just barely see its shiny butt in the photo below.


If you want to help pollinators, don’t buy a fancy bee hotel; just stop tidying up your yard! Small carpenter bees will nest in any old, broken, pithy stem, and when they’re done, all sorts of other things will move into their abandoned tunnels, like this adorable yellow-faced bee (Colletidae: Hylaeus) I saw peeking out of one of our cultivated raspberry canes last fall:


And speaking of wild strawberry (Rosaceae: Fragaria virginiana), yet another leaf-mining fly was just getting started on this leaf yesterday:


Leafminer #58: Agromyza idaeiana (Agromyzidae).  At least I think it’s this one, as opposed to one of the other two Agromyza species that have been reported from strawberry in North America, neither of which I have ever reared. This was the very first leafminer I ever found in our yard: I collected a few mines just like this one on cinquefoil (Rosaceae: Potentilla simplex) on May 22, 2013, the day Julia and I first visited the house. We bought the house in July, and four adults emerged between September 10 and 23, after we had moved in.


Leafminer #59: Coleophora cornella (Coleophoridae).  When I checked the main patch of gray-stemmed dogwood along the border between the “nut orchard” and our neighbor’s yard, I didn’t find any more Phytomyza agromyzina mines, but I did see this:


The larva was still mining away from its portable case on the underside of the leaf:


And on a neighboring leaf I found where it had abandoned its previous, smaller case and excised its current case from a narrow mine formed along the leaf margin:


I haven’t yet reared an adult of this moth. Maybe this will be the year…

Leafminer #60: Agromyza vockerothi (Agromyzidae).  This mine was on another blackberry in the nut orchard. This species was described in 1969 from adults collected in four different Canadian provinces, but it wasn’t until I reared adults from blackberry in Massachusetts (including right near my house) 45 years later, and Owen Lonsdale identified them, that anything was known about its natural history.


Leafminer #61: Microrhopala excavata (Chrysomelidae).  And right next to that blackberry, I found this beetle nibbling on a goldenrod leaf:


Nothing has been published about the habits of this species (except, of course, in my leafminer book), but over a few years of observation and rearing I’ve determined that it always lays its eggs singly, at the margin of a leaf and on the lower surface, carefully coating them with excrement. The larva’s leaf mine has a distinctive dark brown spot in the center where the frass is concentrated.


Leafminer #62: Microrhopala vittata (Chrysomelidae).  In contrast, the leaf mines I found on a goldenrod just 20 feet away had evenly distributed frass, with eggs laid in masses (still covered with poop) deposited away from the leaf margins:


These characteristics identify the maker of the mine as M. vittata—which goes to show that it’s not a good idea to assume that adult leaf-mining insects found in association with mines are necessarily the species responsible for those mines. Microrhopala vittata has been given the common name “Goldenrod Leaf Miner,” a good example of how uninformative and misleading common names can be, given that this is the fifth species of leafminer I’ve found on goldenrod in my yard in the space of a week.


Leafminer #63: Calycomyza novascotiensis (Agromyzidae).  Right next to the M. vittata mines were a couple of mines of this fly on hawkweed (Asteraceae: Hieracium praealtum).


As with Agromyza vockerothi, this species was described from Canada in 1969 and nothing was known of its habits until very recently. The first reared specimen came from a mine on H. praealtum that Julia found while weeding a strawberry bed (within 50 feet of the mines shown above) on the exceptionally early date of March 24, 2016. This adult emerged exactly a month later:


That was the last new leafminer I found yesterday, but on my way out of the nut orchard I paused to look at a red currant bush (Grossulariaceae: Ribes rubrum), and discovered that sawfly #15 had just hatched out:


In the photo above, there is a series of about a dozen oviposition scars in one of the major leaf veins, and three recently hatched larvae can be seen munching away. The eggs are inserted in those scars, so I don’t entirely understand how the egg remains come to be on the surface of the vein—I guess the larvae sort of drag them out as they hatch. But that doesn’t totally explain it, because on the right side of the photo below, there is a larva still curled up in its eggshell and resting on the surface of the vein.


This is a species I see every year: Pristiphora appendiculata. The larvae eat a lot of the leaves; I eat a lot of the berries; the plants are perfectly fine; everybody’s happy. It’s almost as if plants evolved to withstand herbivory and don’t need us meddling in their affairs as much as we think.


At the end of a long day—during which I actually did a lot of yardwork in between documenting all those leafminers—I lay down in the patch of milkweed shown at the beginning of this post and Julia joined me. She spotted this gorgeous moth:


I have no idea what it is beyond being in the family Tortricidae, which are known as the “leafroller moths,” but that doesn’t necessarily mean the larva of this species is a leafroller. And then I spotted something I never would have seen had I not been lying on the ground, looking up at the underside of a goldenrod leaf: sawfly #16.


That little cutie in the upper right corner is responsible for those two little holes nibbled in the leaf, which is interesting because very few North American sawflies have been associated with the aster family. As with all the unknown sawfly larvae I’m finding, I’ll do my best to rear it to an adult so we can find out what it is.



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