The Yard List(s), Part 30

Things are starting to wind down here in central New England, plant-wise, but I’ve managed to add a couple more leafminers and one sawfly larva to the yard list since the beginning of October. Also several parasitoids have emerged, unfortunately from mystery miners I was hoping to rear to adults.

For instance, on October 1 or 2, this eulophid (a Chrysocharis, I’m pretty sure) emerged from one of my few puparia of the unknown Liriomyza on amaranth (leafminer #181).

And at the same time, this opiine braconid emerged from one of the few intact puparia I found of the unknown stem-mining Ophiomyia on Queen Anne’s lace (#179):

Leafminer #204: Aulagromyza luteoscutellata (Agromyzidae), on Morrow’s honeysuckle (Caprifoliaceae: Lonicera morrowii). On October 7 Julia and I were pulling up some unwanted plants along the boundary with the ATV neighbor and I found one mine that can be attributed to this species with reasonable confidence—it certainly isn’t A. cornigera, the only other honeysuckle miner I’ve found in the yard this year (#9). An ant or some other predator had chewed the larva out of the leaf before it could finish mining.

On October 10 I found this perplexing pair of mines on a red oak sapling behind the chicken house:

So far the mines were entirely linear, suggesting a Stigmella rather than an Ectoedemia, but the known oak-feeding Stigmella species have larvae that are either distinctly yellow or distinctly green. The only one I know of that has a larva with a central row of ventral dots like these is S. altella, which (in addition to having a yellow larva) forms a strictly lower-surface mine, whereas these mines were on the upper surface. (Stigmella altella does appear only October, though, and it’s one of the species I was hoping to find in my yard this month.)

On October 13, I found one of the larvae flailing about on the paper towel in the bottom of the jar, now mottled with pink and orange…

…and the other had spun a white cocoon on the side of the jar—further evidence that these weren’t Stigmella altella mining the wrong side of the leaf; that species has a brown cocoon.

Here are the completed mines:

The way the frass is scattered along the full width of the mine is reminiscent of Stigmella nigriverticella, which has a bright green larva. This prompted me to take another look at my photos of Leafminer #148, which I’d asserted was S. nigriverticella but has been bugging me all summer because the frass is much more densely packed in mines of that species. Also, now that I actually look at this confirmed S. nigriverticella mine from Nantucket, I’m reminded that that species has a much narrower and much more evenly widening mine:

I have little doubt now that Leafminer #148, whose mines I found already empty at the end of July, is the same mystery species I just collected by the chicken house. Here are the July mines for comparison:


All four of these mines share a feature that I don’t remember seeing in any other nepticulid mine: a short, dense, narrow central line of frass right before the frass starts to be scattered broadly across the width of the mine. All four of the mines also begin with an egg laid next to a major vein on the upper leaf surface and end with an exit hole in the lower surface. Is this a previously unknown species of Stigmella or Ectoedemia? One of those, I guess. We’ll see if I luck out and get an adult (or salvageable DNA) from one of these larvae. Whatever this turns out to be, it looks like I’ll have to add a 138th couplet to my key to North American oak leaf mines.

Also on October 10, I found the 49th distinct type of sawfly larva for this year’s yard list: a dazzling, solitary one on one of our cultivated hazelnuts (Corylus ‘Medium Long’), unlike any I’ve seen before on that plant.

On October 13, it molted to a prepupa and I transferred it to a jar of soil. When I checked yesterday it had burrowed down to overwinter and pupate.

On October 11, I finally collected the mysterious Leafminer #153, which forms a short mine in a leaf blade of garden phlox before disappearing into the midrib and, I surmised, completing its development as a stem borer without leaving any further external evidence.


I split open a couple of stems that had mines like this, and sure enough, something had been tunneling in the pith:

Since the mine isn’t really visible in the leaf midrib and since the midrib and stem are difficult to dissect cleanly, I wasn’t able to see the mine actually transitioning from the leaf to the pith of the stem, but I confirmed that there was no tunneling in the stem immediately above a mined leaf but there was a tunnel right at the node with the mined leaf. I didn’t want to break apart too many stems for fear of damaging the larvae or pupae that I hope are still inside, but it seems that the tunneling continues all the way to the ground. Hopefully I got enough of the root to capture the mystery bug, and will be able to see who comes out in the spring.

This next one isn’t from my yard, but worth mentioning: On October 12 I awoke to discover that a fly had emerged from one of the jars of soil I keep on the dresser next to the bed—the first sign of life there in several months. It turned out to be a Chirosia (Anthomyiidae) from a leaf mine on silvery spleenwort (Deparia acrostichoides) that Julia and I had collected in Vermont while on a field trip with the New England Botanical Club—on June 16, 2019! Usually there’s no point in keeping a jar of soil around for more than a year, and this one had completely dried out, but I’d been reluctant to give up on it because the single larva that had burrowed into it held the answer to a long-standing mystery that I haven’t had many opportunities to pursue.

So what species of Chirosia is it? I dunno, they all look like this. We’ll find out whenever Brad Sinclair gets to go back to work at the Canadian National Collection and I can send it to him.

Between October 10 and 12 (I haven’t been checking the rearing vials everyday lately because things have really slowed down), a braconid emerged from the Phyllonorycter kearfottella mine on Chinese chestnut that I’d collected on September 27 (#195). I think it’s a miracine:

Multiple times over the past few weeks, I’ve checked the black birch saplings in the “lower nut orchard” for leaf mines of Ectoedemia occultella (Nepticulidae). I’ve only found this species three times in the past decade, and never in my yard, but I’ve just felt like it should be here. And at least as often as I’ve been checking those birches, I’ve been checking our driveway (at the opposite end of our yard) to see if a leaf with one of the “green island” Ectoedemia species has blown in from the quaking aspen across the road. Yesterday, as Julia and I returned from a walk up the Crag, we stopped by the mailbox to look for the latter, and Julia spotted a leaf with a hint of a green island on it—but rather than blowing from the aspen across the road, it had fallen from the paper birch (Betulaceae: Betula papyrifera) at the edge of our own yard. The little bit of green on the otherwise yellow leaf marked the edges of an Ectoedemia occultella mine! So that’s Leafminer #205:

As you can see, this species makes a small blotch mine without any initial linear portion, bounded by two adjacent lateral veins, with a characteristic dark circle in the middle, on the underside of which the tiny, shining eggshell can be found.

It’s been a little while since I updated the list of plants I’ve eaten from the yard this year. Julia says I get to count potted plants on our deck and in the house, since the house is in our yard, so:

118. Ginger (Zingiberaceae: Zingiber officinale) – rhizome
119. Fig (Moraceae: Ficus carica) – fruit
120. Asian pear (Rosaceae: Pyrus pyrifolia) – fruit
121. Butternut squash (Cucurbitaceae: Cucurbita moschata) – fruit/seeds
122. Some sort of melon (Cucurbitaceae: Cucumis melo) – fruit

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The Yard List(s), Part 29

In my previous post, I mentioned having found a couple of leaf mines that needed a little more investigation to decide whether they’re something new for this year’s yard list. Well, I investigated, and they are!

Leafminer #197: Stigmella sp. (Nepticulidae), on paper birch (Betulaceae: Betula papyrifera). On September 27 I plucked a leaf with three narrow linear mines on it from the paper birch sapling at the southeast corner of the yard. I’ll show each of them in top, bottom, and backlit views. Here’s the first one:

The egg was laid next to a prominent vein on the underside of the leaf (lower left corner of the third photo above), but the mine is initially confined to the upper surface, following the vein (first photo above); later it becomes full-depth, visible on both leaf surfaces. The second mine follows the exact same pattern (note the eggshell in the upper left corner of the third photo below):

The third one starts out the same way (note how it starts out following a vein from the right edge of the first photo below, originating from an egg visible at the left edge of the third photo), but then it becomes a mostly lower-surface mine, with a few little full-depth patches.

The little dots of external “window feeding” on the underside of the leaf next to the third mine initially led me to think these were Bucculatrix mines (both birch-feeding Bucculatrix species form short linear mines that they exit to window-feed on the leaf surface), until I saw that all three larvae were still in their mines and realized this feeding sign was from some other insect. The round eggshells and the appearance of the larvae identify these miners as moths in the family Nepticulidae. Consulting the key I wrote to the known North American birch leafminers, I see that a linear mine like this could be the work of one of seven species, but I can rule out the three species of the Stigmella betulicola group because they have distinctly yellow larvae. This leaves two species in the S. lapponica group that are also known from Europe, plus an undescribed Stigmella in the lemniscella group and Ectoedemia quadrinotata, both of which I’ve already found in my yard this year (on black birch and hazelnut, respectively). All four of these have pale larvae like the ones in this leaf. Stigmella lapponica can clearly be ruled out because its mines are initially filled with green frass, whereas these mines have a black central frass line in the early portion.

Two days after I collected the leaf, all three larvae had exited their mines to spin cocoons. Here are backlit views of the completed mines:

Each of these mines is only about 0.5 mm wide at the end—probably the narrowest completed nepticulid mines I’ve seen on any host plant—and in each case the larva exited through a slit on the lower leaf surface. These mines are far too small and narrow for Ectoedemia quadrinotata, which I was already inclined to rule out because the larva of that species has a dark central spot on each segment that should have been visible in my photos. They are also too narrow, and the frass pattern is all wrong, for the undescribed species in the Stigmella lemniscella group. This leaves S. confusella, which is only known from Manitoba outside of Europe. Although that species likewise lays its eggs next to veins on the lower leaf surface, it is said to form “a very long and slender mine, with frass in a continuous, very narrow, central line. The mine follows veins over long distances, giving it an angular appearance.” These mines are certainly slender, but they are by no means “very long”; the frass tends to fill the later portion of the mine; and each only follows a vein at the beginning. They bear little resemblance to the examples shown on the European leafminer website. This is why, when using a key, it’s important not to just accept whatever identification you land on at the end. You should always read the accompanying description and consult whatever illustrations are available to make sure everything fits.

So what species have I got here? I dunno. Some other Stigmella, I guess. Another undescribed species? A European species not previously documented in North America? I look forward to hearing what Erik van Nieukerken has to say about these.

Leafminer #198: Ophiomyia carolinensis (Agromyzidae), on smooth aster (Asteraceae: Symphyotrichum laeve). Weeks ago I had noticed a mine of Acrocercops astericola (Gracillariidae) on this aster growing by the mailbox, and I for a while overlooked the O. carolinensis mine a few leaves up the stem from it because it was superficially similar. I had a nagging feeling about it and finally got around to taking a closer look yesterday. The way the mine alternates between leaf surfaces is characteristic.

Leafminer #199: Phytomyza crassiseta (Agromyzidae), on speedwell (Plantaginaceae: Veronica sp.). Julia and I noticed a few of these mines yesterday when we peeked under the ostrich ferns growing along the side of the garage to look for one of the little leatherwood shrubs we’d planted last year (it turned out a vole or rabbit had recently cut the stem off at the base for no discernible reason).

A backlit view shows the two puparia hidden on the lower surface, each with a longitudinal stripe on its belly:

Last night there were strong winds that woke us up in the middle of the night and made us wonder for a little while if we should go seek shelter in the basement. This afternoon I spent some time picking up branches that had blown all over the front yard, mostly from the big poplar tree at the south edge of the yard.

As I’ve been tallying the leafminers and sawflies in the yard throughout the year, I’ve been looking on this tree with a bit of scorn because it never seems to have any bugs feeding on it. It’s a weird tree that I’d never gotten around to trying to identify before today; it clearly was planted by the previous owners at the same time as a bunch of other oddball trees that are all smooshed together there at the edge of the yard: a silver maple, a pin oak, a pitch pine (which finally died in the past year due to competition with its neighbors), a European larch, and several nonnative spruces (a few of which we cut down several years ago to let some more light into the yard). After checking two botanical manuals, it seems to be Populus × canadensis, a hybrid between the native eastern cottonwood (P. deltoides) and the European/Asian/African black poplar (P. nigra). Today this tree finally started pulling its weight.

Leafminer #200: Aulagromyza ?populicola (Agromyzidae). Just after throwing a big branch on the brush pile, I noticed this mine on the underside of one of the leaves.

A close look at the backlit view below reveals the tiny puncture where the egg was inserted in the leaf; the scattered, fine specks of frass; and the two rows of meconial pillars arranged by a eulophid wasp larva after devouring the fly larva from within. The emerging adult wasp chewed a round exit hole in the lower epidermis between the two rows of pillars, which served to protect the wasp’s pupa from potential collapsing of the mined leaf tissue as it dried.

Aulagromyza populicola is a European species that has been found in Ontario and Oklahoma; this mine was either made by that species or something unknown but presumably closely related (A. populicola is not known to make lower-surface mines, which I’ve found before on cottonwood and bigtooth aspen in South Dakota, Kansas, and Massachusetts).

Leafminer #201: Stigmella populetorum (Nepticulidae)… or another, closely related species in the S. salicis group. I spotted this mine on the lower surface of a leaf on a twig that had blown all the way across the yard and onto the driveway.

Although at first glance this looks like another irregular whitish mine similar to the Aulagromyza one, the egg in this case is deposited on the leaf surface instead of inserted; the mine is initially narrowly linear; and the frass is in a continuous dark line (as in the Stigmella on birch).

Leafminer #202: Phyllocnistis populiella (Gracillariidae)—yet another lower-surface mine, this one on a big branch that landed on the hugelkultur bed. This superficial mine is formed just in the epidermal cells, and it appears silvery or nearly invisible depending on the angle of the light.

Leaf (stem) miner #203: Marmara fasciella (Gracillariidae), on the white pine (Pinaceae: Pinus strobus) sapling at the edge of the leach field. I’m pretty sure I checked this sapling back in the spring when I was on a roll with finding Marmara mines in the yard, but somehow I missed this mine, which clearly has been there all along.

I don’t expect to add too many miners to the yard list in the remaining three months of the year, but you never know…

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The Yard List(s), Part 28

An auspicious beginning for the fall leafminer season!

Leafminer #191: Ectoedemia populella (Nepticulidae), on quaking aspen (Salicaceae: Populus tremuloides). On the morning of September 22, I went to get the paper and noticed this leaf that had blown onto our driveway from a tree across the road:

The swelling in the petiole at the base of the leaf is an incompletely developed gall of E. populella, which naturally is known as the “poplar petiole gall moth.” Although this species spends most of its larval life feeding in the gall, it hasn’t forgotten its leafminer roots. A close look at the underside of the leaf reveals that the egg was laid on the leaf blade, and the newly hatched larva mined along the midrib and into the petiole before causing the gall to form.

I already had Coptodisca splendoriferella (Heliozelidae) as leafminer #135 back in July, when I found it on black cherry, but I couldn’t resist getting a shot of this nice group of mines on an apple leaf—some of the larvae are still feeding, while others have already cut out their oval cases and dropped to the ground in search of a place to pupate and overwinter.

Leafminer #192: Neochirosia nuda (Scathophagidae), on Canada mayflower (Asparagaceae: Maianthemum canadense). I noticed some mines of this fly on a walk in the woods, and I remembered there are some Canada mayflower plants growing along the north side of the shed. I checked them and sure enough, two of the leaves had mines. On the leaf shown below, there are eight brown eggs along the midrib, but only one of them has hatched so far.

Leafminer #193: Synchysa tricincta (Scathophagidae), on false Solomon’s seal (Asparagaceae: Maianthemum racemosum). This species lays white eggs on the lower leaf surface instead of brown eggs on the upper surface. I had been watching for its mines all year, and finally found one on September 22 on a false Solomon’s seal plant I hadn’t noticed before. The mine was probably formed months ago.

Leafminer #194: Calycomyza malvae (Agromyzidae), on hollyhock (Malvaceae: Alcea rosea). Three new leafminers for the yard on the first full day of autumn was already pretty good, but it suddenly popped into my head to check the pathetic little hollyhocks we planted in the shade behind one of the compost bins this summer, and sure enough, there were a couple of larvae mining away.

The next day Julia and I went to Nantucket for the 10th annual survey of leafminers, gallmakers, and other little-known herbivorous insects there. It was a very successful visit; I’ll have more on that sooner or later. We got home on the 26th, and when I walked around the yard the next day, there were a few more leaf mines to be found.

Leafminer #195: Phyllonorycter kearfottella (Gracillariidae), on Chinese chestnut (Fagaceae: Castanea mollissima).

Leafminer #196: Stigmella sp. (Nepticulidae), on Chinese chestnut. I’m not sure exactly what species this is (no North American species has been reported from Chinese chestnut), but it isn’t either of the Stigmella species I’ve found on oak in my yard this year.

I found a couple of other mines that need a little more investigation to decide whether they’re something new. For now, here are some other things I found as I wandered around the yard yesterday.

On September 6 I’d found these red-humped caterpillars (Notodontidae: Schizura concinna) on the underside of a leaf on the little aspen sapling in the front yard—I wrote that they were in varying stages of becoming “mummified” by braconid wasp larvae spinning cocoons inside them.

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When I checked yesterday, I realized that these weren’t actually the caterpillar “mummies” characteristic of braconid wasps in the genus Aleiodes; the wasps here were campoplegine ichneumonids, which spin their cocoons outside their hosts but in some cases wrapped in the host’s skin.

Most of the wasps had already chewed their way out of the cocoons:

In this side view, you can see the white cocoons peeking out under some of the “pelts.”

Nearby, galls of Dryocosmus deciduus (Cynipidae) were bursting out of the midribs of leaves on a little red oak sapling (Fagaceae: Quercus rubra):

The larger red oak sapling in the “upper nut orchard” had some nice fuzzy midrib clusters made by another gall wasp, Callirhytis lanata.

The Tischeria quercitella mines I first noticed on September 5 are coming along nicely.

A little downhill from that oak, a third wave of sawfly #41, which I first noticed as tiny hatchlings, is continuing the work of defoliating the pussy willow (Salicaceae: Salix discolor).

Yesterday the shrub was abuzz with ichneumon wasps trying to lay eggs on these larvae.

They would fly within a few centimeters of the larvae and then turn around and approach them backwards.

Every encounter that I watched ended with the sawfly larva flicking its tail end and the wasp flying away—except in the case of the wasp in the photo above, which was actually knocked off the leaf by the larva immediately after I took the picture.

Back in the “upper nut orchard,” I noticed these elegant poop tubes on the undersides of a few hazelnut leaves; presumably the work of an Acrobasis species (Pyralidae).

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The Yard List(s), Part 27

Time for the end-of-summer update on my project to list all the leafminers and sawfly larvae I can find in my yard, along with all the plants I’ve eaten. It’s definitely starting to get harder to add new species to the lists. On September 16 I remembered we had planted a white wood aster in the area under the old apple tree that is now engulfed in ostrich ferns, so I crawled under the ferns to see if there might be a mine of Liriomyza limopsis on the aster.

The aster was immaculate, but right next to it I noticed a little brown patch on an enchanter’s nightshade (Onagraceae: Circaea canadensis).

I took a closer look, and as I hoped, it turned out to be a leaf mine for which I’d been specifically watching all summer without success:

Leafminer #187: Mompha terminella (Momphidae). From above, I couldn’t be sure it was a mine rather than “window feeding,” in which an insect feeds externally on the lower leaf surface, leaving the upper epidermis intact…

…but a look at the lower surface revealed the frass that the larva had pushed out of the edges of the mine, as is characteristic of this species.

Here’s an adult I reared from a similar mine seven years ago:

This inspired me to look once again for mines of an undescribed Mompha species that feeds on bedstraws (Rubiaceae: Galium spp.). I’ve never found mines in the yard before, but Julia once had an adult land on her in the vegetable garden, so I know the species is here. I went over to a patch of wild madder (G. mollugo) and had a look. No mines to be found, but I noticed a brown tip on a blade of grass poking out of the wild madder patch:

Holding the blade up to the light, it seemed I had finally found a “grass miner moth” (Elachistidae: Elachista) in my yard. But on closer inspection, the frass pattern indicated a fly, and there was a metallic black puparium inside indicating Cerodontha incisa (Agromyzidae), which I’d already listed as leafminer #79 back in June.

Here’s the puparium removed from the mine:

This 1.5-mm wasp emerged from the puparium on September 19. It belongs to the genus Epiclerus in the family Tetracampidae, and is only the second tetracampid I’ve reared out of a few thousand leafminer parasitoids over the course of nearly a decade. (Thanks to Jeong Yoo for the ID; I could tell it wasn’t quite a eulophid because it has five tarsal segments, and was tentatively calling it a miscogastrine pteromalid for lack of a better option but didn’t think it really looked like one.)

You may recall that this time last year, the woolly bear caterpillars were busily cutting down the blue mistflowers (Asteraceae: Conoclinium coelestinum) by our front door (and all around our yard). Well, the plants are all doing well this year, and so far the woolly bears have left them alone. Here’s the one by the front door:

On September 17 I noticed a single leaf mine on that plant:

Leafminer #188: Liriomyza carphephori (Agromyzidae). Four of the paratypes of this species were reared from mines I found on devil’s beggar-ticks (Bidens frondosa) in our front yard on October 8, 2016, and I think this is the first mine I’ve seen in the yard since then. On both hosts, the mine typically starts out as a contorted squiggle at the tip of the leaf and then stretches out into a meandering linear mine toward the leaf base, but in this example the whole mine is bunched up at the leaf tip.

Another thing I’ve been watching for all summer is sawfly larvae on elderberry (Adoxaceae: Sambucus nigra). In the past few years I’ve found Lagium atroviolaceum (Tenthredinidae) just 50 feet or so into the woods from our yard, and right at the edge of the yard I once found a larva of another, unidentified tenthredinid among some berries as I was gobbling them up. Repeated visits this year to the various elderberry bushes the birds have planted around the edges of our yard turned up nothing, but then yesterday evening when I waded into the wild raspberry thicket to check on a persimmon sapling we had planted there this spring, I found two of the unidentified larvae on a small elderberry plant I hadn’t realized was there.

So that brings the total to 48 different sawfly larvae I’ve found in the yard this year. Unfortunately both of these larvae had ichneumon eggs attached behind their heads, so their identity may remain unknown until I can find some un-parasitized ones in some future year.

Leafminer #189: Coptotriche crataegifoliae (Tischeriidae). I found a single mine of this species today on our medlar tree. To my knowledge, this is the first tischeriid mine anyone has ever found on medlar. Medlar has traditionally been known as Mespilus germanica (Rosaceae), but some botanists treat it as Crataegus germanica, and apparently this moth agrees (though I’ve also found its mines on Amelanchier and Aronia, so this isn’t really a strong argument for accepting that medlar is just a thornless hawthorn with big, tasty fruits).

The clean appearance of this mine is explained by a tiny hole at the beginning on the lower surface, through which the larva expels all of its frass (right above the “i” and the “s” in the photo below).

I checked out a “real” hawthorn (Crataegus sp.) nearby and found one more new species for the list:

Leafminer #190: Stigmella oxyacanthella (Nepticulidae). At least, I’m pretty sure it’s this species, which I’ve reared from both hawthorn and apple in my yard in the past. The mine of this species isn’t really distinguishable from the mine of S. scintillans (#114), but S. scintillans has yellow larvae that are present from June to August, and S. oxyacanthella has green larvae that are present in September and October. I’m basing my ID on the freshness of this mine; hopefully I’ll find some green larvae in the next week or two to remove any doubt.

The apparent yellowish mottling in this backlit photo of the mine, and the darker mottling surrounding it, is actually a colony of aphids on the underside of the leaf:

I think the older ones look pretty sporty with their four green spots.

And finally, the “plants I have eaten” update…

111. Apple (Rosaceae: Malus pumila) – fruit
112. False Solomon’s seal (Asparagaceae: Maianthemum racemosum) – fruit
113. Black nightshade (Solanaceae: Solanum ptychanthum) – fruit
114. Sweet potato (Convolvulaceae: Ipomoea batatas) – root
115. Sunflower (Asteraceae: Helianthus annuus) – fruit/seeds
116. Hazelnut (Betulaceae: Corylus ‘Medium Long’) – nut

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The Yard List(s), Part 26

Before I launch into the latest leafminers from my yard, I have a few sawfly updates. On July 11 I had collected this spotty larva on black raspberry:


It burrowed into soil to pupate five or six days later. Alas, on September 8, this ichneumon wasp emerged, much like the one that emerged on August 26 from the un-spotty larva on red raspberry.

Since a tachinid fly emerged from a larva I found on blackberry, it’s looking pretty unlikely that I’ll get any adults of these mystery Rubus-feeding sawflies. I guess there’s always next year…

On September 1 I had found these larvae feeding together on a hazelnut leaf, and the larger one matched the ones from which I’ve reared Arge willi (Argidae) in the past, but I wasn’t sure if the smaller ones were the same thing.

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On September 7 they still had red heads…

…and they looked the same on September 11, but on the 12th they had brown heads and resembled the larger larva (which had already spun a cocoon by September 7), so they are in fact all Arge willi:

Sawfly #47: Caliroa sp. (Tenthredinidae), on red oak (Fagaceae: Quercus rubra). On September 5, right next to the leaf mines of Tischeria quercitella, I found a solitary “slug” sawfly larva feeding on the underside of a leaf. I didn’t mention it in my previous post because I wasn’t certain it wasn’t a younger version of the same species I’d found on Chinese chestnut, but now that I’ve finished watching it develop I can confidently add it as another distinct Caliroa for the yard list—after #26 on quaking aspen, #36 on shadbush, #39 on Chinese chestnut (Caliroa ?lobata), and #43 on pear (Caliroa cerasi). When I found the larva it had recently molted, and its head and legs were colorless, but it was evident from its shed skin that the previous instar had had a brown head and legs. (The “floating” fecal pellets in these photos are caught in a spider web that was spun across the underside of the leaf.)

Here’s the same larva the next day, with its head and legs now colored in. I caught it at an awkward moment when its body was twisted, showing a full suite of abdominal prolegs.

This was the final instar, and it had molted to a prepupa when I checked on the morning of September 10:

In contrast with Caliroa lobata, the larva never got more than a slight hint of yellow on the thorax, and the head and thorax never got quite as dark as in that species. Also, C. lobata is consistently gregarious, and this species seems to be solitary. On September 13 on a walk in the woods behind our house, I found recently hatched larvae that I think are C. lobata (again on red oak), and I learned that even at this stage they have a distinctly yellow thorax and dark legs and head. Here’s what their “window feeding” looked like from above; the dots to the right indicate where the eggs were laid:

The same scene from below:

And a closer look:

On to the leafminers (interspersed with some other creatures found in the garden).

Leafminer #181: Liriomyza sp. (Agromyzidae), on amaranth (Amaranthaceae:  Amaranthus hybridus). I found several of these mines in the lower vegetable garden on September 8 while browsing on cherry tomatoes and ground-cherries. I’ve only seen these mines once before—when Julia found some on a farm just over the border in New Hampshire—and I’m reasonably sure they don’t represent any of the Liriomyza species known to feed on amaranth (L. huidobrensis, L. sativae, and L. trifolii, all of which are polyphagous species that I’ve never found in New England). This species likes to switch back and forth between the upper and lower leaf surfaces, as you can see here:

On September 11, Julia was turning the compost in the upper vegetable garden and found a nest… no doubt belonging to the same voles who have been relentlessly cutting down the bean plants all season.

Leafminer #182: Stigmella rhamnicola (Nepticulidae), on common buckthorn (Rhamnaceae: Rhamnus cathartica). I am by no means a native plant purist, but there are certain plants that don’t “play well with others,” and which we try to pull up whenever we find them on our land: common buckthorn, glossy buckthorn, multiflora rose, Oriental bittersweet, Japanese barberry, Morrow’s honeysuckle, and black swallowwort. Several of these plants are utilized by native leafminers—in my last post I showed mines of the beetle Sumitrosis rosea on bittersweet—and common buckthorn is another example. I wrote about its use by Stigmella rhamnicola seven years ago; as I noted then, this native moth is surely much more common in New England now that this European plant is widespread here. On September 12 I spotted a couple of small plants that had sprouted up among the brambles in the “upper nut orchard,” and when I pulled them up I found several old, aborted or predated mines:

I also recently found some mines of the native Stigmella rosaefoliella on some multiflora rose that is just outside what I can reasonably call my yard, so I don’t get to add that species to the list (yet…).

On the morning of the 14th, while washing the kale leaves we had picked for breakfast, Julia found a cabbage white caterpillar with a mass of braconid cocoons. These cocoons (and the caterpillars) are a common sight in the hoop house right now, but this one still had a freshly emerged braconid larva that hadn’t started spinning its cocoon yet:

Later that morning, I decided to check on the small American elm tree at the west edge of the yard to see if any new leafminers had shown up since I last looked. It did not disappoint.

Leafminer #183: Phyllonorycter argentinotella (Gracillariidae).

Leafminer #184: Ectoedemia ulmella (Nepticulidae).

Leafminer #185: Stigmella apicialbella (Nepticulidae).

A search of other plants in the yard turned up one more new species for the year:

Leafminer #186: Ectoedemia quadrinotata (Nepticulidae), on cultivated hazelnut (Betulaceae: Corylus ‘medium long’). It’s theoretically possible that this mine was made by E. virgulae, but I’ve reared E. quadrinotata from the yellow birch in my yard in previous years and have never seen any evidence that E. virgulae is here. This is also identical with the E. quadrinotata mines I’ve seen on hazelnut elsewhere.

Here’s one of the ones I reared from yellow birch, displaying the four spots (per wing) that give it its name:

I’m undecided about whether this little excavation at the tip of a blue spruce needle (from one of the trees at the north edge of the yard) deserves to be called a mine. If I get to the end of the year and find that my yard leafminer tally is at 199, I might have to call upon it to get to an even 200, but we’ll ignore it for now…

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The Yard List(s), Part 25

Remember a few days ago when I showed photos of a Cameraria larva mining in a red maple leaf and wondered if both maple-feeding species have such dark larvae?

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(The second photo is a backlit close-up of the mine at the right side of the first photo.) Well, take a look at this mine I found on September 5 on a sugar maple (Acer saccharum) behind the chicken run:

I think we have our answer. I reviewed my photos of mines from which I’ve reared the two species, and I’m pretty sure the dark larva (Leafminer #161 for my yard list) is Cameraria aceriella, and the pale larva with dark markings (Leafminer #172) is C. saccharella. I went back to check on the red maple mines, and unfortunately I won’t be able to track their progress. The larger mine had progressed some but then a predator had torn open the upper epidermis and removed the larva:

The larva in the smaller mine had been devoured by the larva of a eulophid wasp, which had now pupated in the middle of the mine:

There were a few other Cameraria mines on nearby red maple leaves, but the larvae in them look the same as the ones on sugar maple. I’ll try an keep an eye on the situation.

Leafminer #173: Tischeria quercitella (Tischeriidae), on red oak (Fagaceae: Quercus rubra). At last, the BugTracks mascot (see the banner at the top of this blog) has made an appearance in my yard!

Leafminer #174 / Sawfly #44: Profenusa thomsoni (Tenthredinidae), on gray birch (Betulaceae: Betula populifolia). Earlier this season, I had found mines of two other introduced leaf-mining sawflies on the paper birch sapling at the edge of my yard, but I hadn’t checked the gray birch sapling next to the black walnut in the “upper nut orchard” until now. There were several old, tattered mines of P. thomsoni on it.

Leafminer #175: Aspilanta argentifera (Heliozelidae), on the clump of sweetfern (Myricaceae: Comptonia peregrina) on the other side of the walnut. I’ve now found three of the six species in this newly described genus in my yard this year. Let’s see if I can also find A. viticordifoliella on Virginia creeper; the other two don’t occur anywhere near New England.

Leafminer #176: Ectoedemia ?similella (Nepticulidae), on red oak. This mine more or less matches the description of E. similella, but there are two undescribed Ectoedemia species known from oaks in the eastern US (at least one of them occurring in Massachusetts), and I’m not sure how their mines differ. The single mine I found already had an exit slit (at lower right in the photo below)…

…so I was surprised to discover that the larva hadn’t left yet.

Within a few hours, the larva did find its way out of the leaf:

Leafminer #177 / Sawfly #45: Profenusa sp. (Tenthredinidae), on the same red oak sapling. To decide between P. alumna and P. lucifex I’d need a close look at the larva and count the segments on the antennae and legs, although only P. lucifex has been documented feeding this late in the season.

I found another one of those lower-surface Marmara mines on tall blue lettuce, this one on a plant growing by the door to the shed. It appeared to me at the time that this mine entered the leaf midrib and continued to the base (evidently entering the stem, but there was no visible mine there). Now that I look at the photos, though, it appears that the midrib mine just passes by the leaf blade mine without interacting with it, and I think the larva is still in the blade where one of the main lateral veins meets the midrib. I’ll have to take another look at that today. None of the other mines I’ve been monitoring has shown any sign of entering the midrib. I do think the mine on the midrib is another Marmara though (same species or a different one, I couldn’t say).

The midrib mine is easier to see in this photo I took without the flash (this is a section closer to the base of the leaf):

And here’s the midrib mine disappearing into the stem:

Next to the shed, at the south end of the yard, is part of a big white pine tree that we cut down several years ago to let in more light. Because the pine was crooked, and because it fell on top of a small black cherry tree that is still alive, it isn’t lying flat on the ground, and there is now a tangle of dense vegetation growing through and around the two fallen trees. This jumble of dead and living vegetation, which we’ve enhanced by piling brush under and next to the pine, is a great wildlife habitat feature, and the catbirds are especially fond of it. It’s also a good place for unwanted plants to get a foothold before we notice them, and after inspecting the tall blue lettuce I noticed a big Oriental bittersweet vine (Celastraceae: Celastrus orbiculatus) twining up some of the branches of the bent-over black cherry (which are now vertical and acting like trunks). I uprooted the vine and pulled it free from the cherry, then laid it down on the ground to check it for evidence of the one leafminer I’ve ever seen on bittersweet. I wasn’t disappointed.

Leafminer #178: Sumitrosis rosea (Chrysomelidae). This native beetle mines leaves of a variety of legumes (Fabaceae), but somehow it has decided that bittersweet (both native and nonnative) and wood nettle (Urticaceae: Laportea canadensis) are also acceptable hosts. I found several old, long vacated mines on this bittersweet vine.

Here’s another mine where the larva (at right) died for some reason while it was very young; at left you can see the oval eggshell embedded in a small pit in the leaf chewed by the mother beetle.

On the same bittersweet vine, I found two examples of what seemed to be aborted underside tentiform mines of a gracillariid moth. I figured they must have been a cherry-feeding species and that the female had goofed and laid a few eggs on the vine that was twined around the cherry; the larvae had developed a little bit before dying due to the unsuitable host. This sort of thing is known as “xenophagy.”

Note the object at the lower edge of the “mine” in the above photo, which looks about right for an eggshell of a gracillariid. Here’s the same “mine” backlit:

And here’s the other “mine”:

I found one other interesting thing on one of the bittersweet leaves, which it is now clear was the same phenomenon:

These mine-like features were not made by larvae feeding inside the leaves; they are places where a leafhopper inserted rows of eggs side by side! If you didn’t notice them before, look back at the two backlit views and you can see that the first “mine” has punctures indicating the insertion points of three eggs; the second one has six, and in the upper-surface view of the third example, there are seventeen. As for the “eggshell,” I think it’s actually a scale insect. It’s amazing how often they happen to position themselves at the edges of leaf mines so that they appear to be eggs. Take, for example, the one at the beginning of a Cosmopterix clemensella mine on a sedge leaf (there is a close-up of the scale here):

Leaf (stem) miner #179: Ophiomyia sp. (Agromyzidae), on wild carrot / Queen Anne’s lace (Apiaceae: Daucus carota). I was excited to find this mine on the evening of September 5:

No Ophiomyia is known to feed on wild carrot, but Julia and I found a bunch of similar mines on an isolated clump at Black Rock Forest in New York late last August while conducting our survey for leaf-mining moths there. The puparia in those mines were all black, and only eulophid wasps emerged from them. The puparium in the above mine (visible as a bulge along the upper margin of the stem) was whitish; unfortunately it turned out to be empty already.

In this close-up, the pair of little black anterior spiracles of the puparium are visible poking through the stem epidermis at far left, and there is a longitudinal opening associated with those—along with a more conspicuous transverse slit to the right of them—indicating that the fly has already emerged. I spent a good chunk of yesterday pulling up wild carrot stems around the yard, and I found six stems with intact puparia (plus one more empty one, and one or two that seemed to still have larvae in them). To give a sense of how sparsely distributed these mines are, this is how many stems I had to inspect to find a half dozen of them (note Brenda in the background; she followed me around for most of the time that I was pulling them up, and was often literally underfoot):

All of the mines were confined between two nodes in the stem as in the example shown above. John van der Linden has observed similarly constrained stem mines (both agromyzid and Marmara) on Ageratina altissima, Polymnia canadensis, and Veronicastrum virginicum in Iowa.

When I found the first mine yesterday morning, I ran inside to get a camera, and in my hurry to get back outside I didn’t bother to put my shoes back on. This turned out to be a mistake, as my right pinky toe soon met with an unseen bee, who left this in it:

Leafminer #180: Keiferia sp. (Gelechiidae), on clammy groundcherry (Solanaceae: Physalis heterophylla var. heterophylla). While Brenda and I were nibbling berries and pulling up wild carrot stems between the two largest rows of red raspberries, I noticed some mines on the perennial groundcherries growing beneath them. These groundcherries pale in comparison with the annual ones that are also in our yard, in terms of both quantity and deliciousness of fruit, but I guess they’ve earned their keep now.

Running the mines through my Physalis key, they would seem to be the work of the undescribed Keiferia species that has been reported only on the glandular-haired variety of P. heterophylla. Elsewhere in the yard, as I passed another patch of clammy groundcherry, I thought I spotted the first flower of the season out of the corner of my eye, but it turned out to be a big yellow crab spider waiting for lunch to drop by:

When I came around to the driveway in my wild carrot-pulling / stem miner-hunting expedition, Julia exclaimed that the garden loosestrife (Primulaceae: Lysimachia vulgaris) in the adjacent perennial bed was all sawfly-eaten. Sawfly larvae show up on these plants every year, and I’d been watching for them, but I guess I hadn’t looked in a while:

Sawfly #46: Monostegia abdominalis (Tenthredinidae). This sawfly, like garden loosestrife, is introduced from Europe. I’ve never seen it feeding on native Lysimachia species, like the fringed loosestrife (L. ciliata) growing wild on the other side of our yard. I think it’s great that the plant and the sawfly have found each other here; garden loosestrife spreads pretty aggressively, and it’s nice to have something keeping it in check. There were no green leaves left on any of the plants yesterday, and I thought I was going to have to settle for a photo of one of the shed larval skins that were draped over some of the remaining leaf fragments, but then I spotted this one straggler munching away on a leaf that had a little bit of green left on it:

I’ll close with a few miscellaneous sightings from yesterday that are neither sawflies nor leafminers. Toward the southeast corner of the front yard, there is a little aspen sapling that started out this spring as an unambiguous bigtooth aspen (Populus grandidentata), and has gradually turned into a quaking aspen (P. tremuloides) over the course of the season. I’ve been checking it regularly because it has already yielded two sawfly species that I haven’t found elsewhere in the yard, and a week or so ago I noticed that a clutch of red-humped caterpillars (Notodontidae: Schizura concinna) were beginning to defoliate it. These show up in the yard every year; sometimes on cherry, other times on persimmon. When I checked on them yesterday, there were a few hanging out in plain sight…

…but most of them were hanging out on the underside of a leaf, where they were in varying stages of becoming “mummified” by braconid wasp larvae spinning cocoons inside them.

A few goldenrod plants were displaying the lovely reddish galls of Schizomyia racemicola (Cecidomyiidae) among their flowers.

And several inches of a branch on one of our asparagus plants was encrusted with hundreds of eggs of some sort of owlet moth (Noctuidae).

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The Yard List(s), Part 24

If you’ve been following along throughout my cataloging of the leafminers and sawfly larvae I’m finding in my yard this year, you may remember that in the first half of July I found several free-living sawfly larvae—representing at least two different species—on raspberry and blackberry. I have no idea what they are beyond family Tenthredinidae, so I collected each one hoping that I can rear some to adults. One was this plain-headed larva I found on blackberry on July 11 (which seemed to be the same as #32 on red raspberry):


It burrowed into soil to pupate on July 15, and I didn’t expect an adult to emerge until next spring, but on August 26 I noticed something moving in the jar. Alas, it was an ichneumon wasp which had been living as a larva inside the sawfly larva:

This prompted a thorough checking of all my jars of soil, which turned up a fourth adult from my jar of five aspen-feeding Caliroa sawfly larvae, and, darn it, a long-dead tachinid fly from the #32 red raspberry sawfly larva, which I had collected on July 8, and which had burrowed into soil on July 11.


We’ll see how the few other Rubus sawfly larvae fare, although I think they may have all been of the other type, with a dark marking on the head. In the meantime, a number of other species have appeared in my yard in the past week.

Sawfly #39: Caliroa ?lobata (Tenthredinidae), on Chinese chestnut (Fagaceae: Castanea mollissima). On August 29, I noticed some patches that reminded me of the “window feeding” caused by gregarious Caliroa larvae on the undersides of oak leaves.

I’d never seen this on chestnut before, but I flipped the leaves over and found two larvae still grazing away on the smallest spot (there were several much larger patches but the larvae that made them had already dropped to the ground to pupate).

Not all Caliroa larvae have been described, but among those that have, the yellow-sided thorax and dark head and legs make these a perfect match for C. lobata, as documented in a paper I recently published with Dave Smith*. So far that species has only been reared from oaks, but all sorts of oak-feeding insects have turned up on our Chinese chestnuts, so it won’t be surprising if these turn out to be the same thing.

One of them molted to a prepupa on September 2:

The other did the next day, and both burrowed into soil as soon as it was offered. But back to August 29…

Leafminer #161: One of two maple-feeding Cameraria spp. (Gracillariidae), on red maple (Sapindaceae: Acer rubrum). A couple of tiny mines just getting started on this leaf:

As far as I know, Cameraria aceriella and C. saccharella can’t be distinguished at this stage, although I wonder if both species have such dark larvae. I’ll keep an eye on them… The mine on the right is just 8 mm across, but in a backlit closeup, we can see that the larva has already molted once. (The head capsule is near the bottom of the photo, and the rest of the shed skin is right by the tip of the larva’s abdomen.)

Right near the chestnut and maple, I noticed this long, narrow, linear mine formed entirely on the lower surface of a grass-leaved goldenrod leaf (Asteraceae: Euthamia graminifolia).

Ophiomyia euthamiae (Agromyzidae) was described from a series of flies I reared from similar mines found within 100 feet of this one, but each of those mines switched to the upper surface, where the puparium was formed. The single mine like this—with everything including the puparium being on the lower surface—produced an adult of O. maura, which is a species I’ve already included on this year’s yard list based on upper-surface mines on Solidago goldenrods. (Yes, oddly, on every other known host, O. maura forms exclusively upper-surface mines.) So I’ll have to find an unambiguous mine of O. euthamiae before I can add that species to the list.

Leafminer #162: Mompha argentimaculella (Momphidae), on evening primrose (Onagraceae: Oenothera biennis).

I’ve been watching for this one all summer on the abundant evening primrose around the yard, and finally spotted this one mine out of the corner of my eye when I went down to check on the tiny baby chicks, who had wandered through the fence that surrounds the chicken run but weren’t getting into too much trouble.

Leafminer #163: Phytomyza lactuca (Agromyzidae), on tall blue lettuce (Asteraceae: Lactuca biennis), on the other side of the chicken run. I had never before seen a mine of this species, which mines exclusively on the undersides of leaves, and I only noticed this one because this particular leaf had flopped over.

I found several other P. lactuca mines on the same plant, but in each case the puparium had an exit hole of a parasitoid wasp. I thought it would be nice to rear an adult of this species, so I visited a bunch of other tall blue lettuce plants around the yard, flipping leaves over, without finding anything. Until, that is, I got to the exceptionally tall plant by the vegetable garden that I showed at the end of my previous post. I found a mine there that still had a larva inside, but when I took a picture of it, the mine seemed to have a continuous central frass line, indicating a moth rather than a fly:

I thought I was seeing things, but a photo with my better camera setup showed this more clearly:

Leafminer #164: Marmara sp. (Gracillariidae), on tall blue lettuce. The only previous indication that there is a lettuce-feeding Marmara is a series of observations Mike Palmer made in Oklahoma, involving empty or aborted mines that were either formed entirely in the stem or began on the upper leaf surface and led into the stem (or crown, in the case of basal rosettes). Could this be the same species? I have no idea; either way, it doesn’t have a name. I didn’t try for a super close-up for fear of squishing the larva, but this backlit shot shows enough detail to confirm it’s a Marmara:

I found a few other Marmara mines on this same plant, all of them visible only on the lower surface. I’m going to wait until the larvae are nearly mature before collecting the leaves, since lettuce leaves don’t last long once picked. A week later, they haven’t made much progress; Marmara larvae are not the speediest of leafminers.

Leafminer #165 / Sawfly #40: Metallus rohweri (Tenthredinidae), on blackberry (Rosaceae: Rubus allegheniensis). The raspberry leaf-mining sawfly, M. capitalis, appeared in my yard back on June 18 and its second round of larvae showed up a little while ago, but M. rohweri, which has just one generation per year in Massachusetts, waited until August 30 to make its appearance.

Leafminer #166: Aspilanta ampelopsifoliella (Heliozelidae), on a Virginia creeper vine (Vitaceae: Parthenocissus quinquefolia) growing up the trunk of the silver maple. An aborted mine, but recognizable by its prolonged initial linear portion. This species was, until a few weeks ago, known as Antispila ampelopsifoliella**.

Leafminer #167: Glaucolepis saccharella (Nepticulidae), on red maple.

This is Brenda, who accompanied me on my leafminer hunt that day.

Leafminer #168: An unknown insect on Siberian iris (Iridaceae: Iris sibirica).

I found this single mine on a leaf right along the driveway. It doesn’t look like Cerodontha (Agromyzidae), and the only other known iris leafminers is Macronoctua onusta (Noctuidae), which makes narrow leaf mines in the spring, later feeding within leaf sheaths and boring in flower buds, stalks, and eventually the rhizome. If this is a mine of that moth, that would mean it’s been there all year and I somehow didn’t notice it until now. I’ll have to look for feeding signs of older caterpillars.

Sawfly #41, on the same pussy willow (Salicaceae: Salix discolor) that has already hosted two generations of another sawfly species this year (#9). On the morning of August 31, before heading out for our last day of dragonfly surveys, I dashed out to collect some willow leaves to feed some other sawfly larvae I had found at work a few days earlier, and I discovered that these larvae had just hatched from a cluster of eggs on the underside of one of the leaves:

Whereas the previous willow sawfly larvae had grazed on one leaf surface throughout their development, these had begun eating holes in the leaf immediately after hatching. On September 2 when I went out to collect some more leaves for the ravenous larger larvae, the leaves more often than not had clusters of still unhatched eggs on the undersides (which doesn’t bode well for the longevity of those leaves):

Most clusters looked like the one above—translucent shells with black-headed embryos visible inside—but in one, the eggs had cloudier shells and a pair of red eyespots at one end.

The latter turn out to represent the former at a later stage; this morning I found that all the eggs in the second photo had hatched, and the ones in the first photo are now cloudy with the red eyespots.

Leafminer #169: Cameraria betulivora (Gracillariidae), on yellow birch (Betulaceae: Betula alleghaniensis). Since it’s getting to be the time of year for all sorts of Cameraria to show up, on September 1 it occurred to me to check the yellow birch at the edge of the woods where I’d found this species a few years ago. I parted the grapevines that have engulfed the tree, and there the mines were:

Leafminer #170: Chirosia gleniensis (Anthomyiidae), on sensitive fern (Onocleaceae: Onoclea sensibilis). And right next to the yellow birch was a single old mine made by three larvae of this fly, in the very patch of ferns I had checked multiple times this year without success.

If you look closely, at the left side of the photo below you can see the cluster of three whitish eggs from which the larvae hatched.

Leafminer #171: Antispila cornifoliella (Heliozelidae), on gray dogwood (Cornaceae: Cornus racemosa). Similarly to the pair of Metallus sawflies on Rubus species, there are two Antispila species on dogwoods in my yard, one of which (A. freemani) appeared early in the season and is now in its second generation, and the other is just now making its first appearance.

In a backlit view, we can see that the larva started by making a narrow linear mine along a lateral vein and the midrib, causing the reddish discoloration seen above.

Sawfly #42: Arge willi (Argidae), on hazelnut (Betulaceae: Corylus ‘Medium Long’). Every year this species appears on our cultivated hazelnut in large numbers, and I’ve been wondering why they aren’t showing up this year. Finally on September 1 I found a single larva matching the ones I’ve reared before, hanging out with several young ones with reddish heads. Whether these turn out to be the same species remains to be seen.

Also on that hazelnut was one of those green lacewing larvae that run around with fluff piled on their backs. It was in constant motion, making it incredibly difficult to get a shot that was at all in focus.

Sawfly #43: Caliroa cerasi (Tenthredinidae), the pear slug, on our newest pear tree. It baffles me that this is considered to be a pest worth worrying about; I never find larvae in large numbers, and they just do a little “window feeding” nibbling here and there (whereas some of the other sawfly species in my yard do defoliate entire branches). I think I had noticed some nibbles a little earlier in the season, but on the evening of September 1 I made a more concerted effort to find the larva responsible for them. Here is some lower-surface window feeding, as seen from above and below:

Unlike most Caliroa species, which feed strictly on the lower surface, the pear slug may feed on either surface, and it was next to an upper surface feeding patch that I found a shed skin confirming that it was actually a Caliroa larva doing the feeding.

Julia walked over and joined the search, and she was the first to spot the actual larva:

To the uninitiated it would appear to be just a wet lump of poop, but here’s its face peeking out from under its shroud of slime:

And on that note, I’ll sign off for the weekend!

* Eiseman, Charles S. and David R. Smith. 2020. New sawfly (Hymenoptera: Argidae, Tenthredinidae) host records from northeastern North America. Proceedings of the Entomological Society of Washington 122(2): 299–307.

** Nieukerken, Erik J. van and Charles S. Eiseman. 2020. Splitting the leafmining shield-bearer moth genus Antispila Hübner (Lepidoptera, Heliozelidae): North American species with reduced venation placed in Aspilanta new genus, with a review of heliozelid morphology. ZooKeys 957: 105–161.

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The Yard List(s), Part 23

Over two weeks since my last update. In a few days my life will become less busy (I think?) and I should be able to explore my yard—and write about what I find in it—more regularly. In the meantime, here’s what I’ve bumped into over the past 18 days… as usual, I have some updates on previous finds as well as new ones to report.

On July 14 I had collected three Agromyza larvae mining in sunflower leaves in our vegetable garden, which could conceivably have been A. ambrosivora (which I found mining ragweed leaves in our yard), Arudbeckiana (which I found mining Heliopsis leaves along our driveway), or another species that hasn’t been reared before. All three larvae exited and formed puparia within a few days. One emerged as an adult female on July 29:


I needed a male to find out what species they were, but luckily there were two puparia left. On August 9, this braconid wasp emerged from one of them:


And this pteromalid emerged from the remaining one on August 23, so I guess I’m out of luck.


In Part 22, I wrote about some agromyzid fly mines on apple mint (leafminer #150) that seem to match those of the European species Phytomyza tetrasticha, which isn’t known to occur in North America. Since August 9, least two different species of eulophid wasps have emerged from those mines, including several eulophines (probably Pnigalio)…


…and a single tiny entedonine, just 0.6 mm long.


On August 20, the first of 18 adult flies emerged.


It was a female, but there have been plenty of males since, including this one…


…so we’ll be able to confirm their identity eventually. I can’t help but wonder if these and the oregano miners I found earlier this summer are the same species; Phytomyza origani and P. tetrasticha are closely related (both belonging to the obscura subgroup of the Phytomyza obscura group), and what are the odds that two European species that look the same, make identical leaf mines, and have never been found in North America before, both show up in my front yard at the same time? But as far as is known P. origani feeds only on oregano, and P. tetrasticha feeds only on mints in the genus Mentha, so we’ll go with that assumption for now.

Sawfly #38: Aglaostigma semiluteum (Tenthredinidae), I presume… because this is the only sawfly known to feed on jewelweed (Balsaminaceae: Impatiens capensis). I found one of these larvae in Vermont on August 11, 2005, and failed to rear it, not really knowing how to go about it at that point. I never saw another one until August 10 this year, when I spotted three of them right where Julia and I parked to conduct a dragonfly survey about 50 miles west of our house (these surveys have occupied most of our waking hours since the last week of July). When we got home that evening, I checked the jewelweed patch behind the chicken run and noticed a white speck at the edge of a leaf, which I guessed correctly was the recently shed skin of a sawfly larva that was now curled up on the underside of the same leaf. By the time I had carried the leaf inside, the larva had moved to the upper leaf surface:


These jewelweed sawfly larvae, like some other species on various other plants, secrete a white, waxy bloom that covers their skin. They lose this covering each time they molt, as the above larva illustrates nicely. Here’s the same larva on August 18:


It’s tricky to get a look at this larva at the right angle to see its big black “nose.”


Here’s the larva again on August 22, looking more evenly glaucous:


Leafminer #151: Stigmella purpuratella (Nepticulidae), on apple. I’ve never found mines of this species before; all the mines I’ve found on our apple trees before have been the introduced European species S. oxyacanthella, which doesn’t show up until September. On August 12 I found two mines that were already empty, one on our “Spigold”…


…and one on our Winesap:


In Part 22, I wrote about the grape leafminer Antispila isabella, sharing a photo of “an adult that emerged on July 10 from a leaf mine Julia and I collected on August 29 last year at Black Rock Forest in New York—clearly a species with just one generation per year, especially given that I removed the pupal case from winter refrigeration way back in February.” Just a few days after I made this proclamation—on August 13—an adult emerged from one of the mines I’d collected in the yard on July 20.


Another emerged within a few days after that, while I was teaching a weekend workshop in Vermont. There is obviously more to be learned about A. isabella, which as I already mentioned is a name being applied to at least two distinct species. Whether one of them has a single generation per year and another has two or more, remains to be seen.

On Monday the 17th, I took a rare day off and actually got to devote a few hours to wandering around the yard. I found this glorious creature, a “monkey slug” caterpillar (Limacodidae: Phobetron pithecium), on the pear tree we planted this spring:


Last fall we embellished the wildest part of our front yard with some native-ish mints, including some spotted beebalm (Lamiaceae: Monarda punctata) that was now in full bloom and being thoroughly appreciated by a variety of fancy wasps:


These bigger ones weren’t very good at holding still long enough to be photographed, and my camera was having a hard time appreciating how blue and shiny their wings were, but this gives you some idea:


Two years ago, I noticed that some bird or mammal had planted the European subspecies of highbush cranberry (Adoxaceae: Viburnum opulus ssp. opulus) at the edge of our yard. I decided to leave it there, since although nonnative it doesn’t seem to be particularly invasive, and I’ve now been rewarded with a mine of…

Leafminer #152: Marmara viburnella (Gracillariidae), the first moth species I had the honor of naming, which I first found on the island of Tuckernuck in September 2011, and which Julia and I spent the next four years learning about before finally succeeding in rearing it. We reared it from arrowwood (Viburnum dentatum), but I’ve seen it on various other viburnums, including in the last year or two a hobblebush (V. lantanoides) within a few miles of our house. But this is the first time I’ve found it on highbush cranberry, or in our yard. Here’s the initial squiggle in the leaf blade…


…and here you can see the mine moving from the leaf blade, down the petiole, and into the stem:


It continued all the way down the newer, green part of the stem, disappearing behind the brown bark from previous years, where the larva will keep mining until next June.


Our groundnut plants have yet to deliver any leaf mines of Odontota scapularis, but they’re worth having around just for their striking flowers (seen here with a planthopper, Metcalfa pruinosa), though of course their prolific, delicious and nutritious tubers are a nice bonus.


This spring we sprouted some cardinal flower (Campanulaceae: Lobelia cardinalis) from seed, and a couple of plants are now blooming in the drainage swale we dug across the front yard last fall:


Here’s a wild turkey walking by one of them on August 19—a whole herd came through, with a few wandering onto our front stoop. I took this picture through the window by the front door.


I don’t remember specifically planting garden phlox (Polemoniaceae: Phlox paniculata), but it’s been jumping around our yard for a few years now.


I’ve been watching it closely for leaf mines of Liriomyza phloxiphaga (Agromyzidae), which is known from a single specimen I reared from phlox in my mother’s garden three years ago. No luck so far, but on August 17 I did find this:

Leafminer #153: A heretofore unknown leafminer that forms a narrow linear mine in leaves of garden phlox, soon entering the midrib and presumably continuing into the stem—as with Marmara viburnella, but this isn’t a Marmara; at this point I’m not sure what insect order it belongs to. I can’t see an eggshell at the beginning of the mine, there is no evident frass or larva when I backlight the leaf, and there is no external evidence of feeding in the stem.


I’ve found one other example so far, right next to the garage.


Leafminer #154: Phyllocnistis ampelopsiella (Gracillariidae), on Virginia creeper (Vitaceae:  Parthenocissus quinquefolia).  This species mines exclusively on the undersides of Virginia creeper leaves, with little or no visible sign on the upper surface. Julia can attest that I’ve been checking the undersides of the leaves of the vine growing up the rock at the entrance to our driveway pretty much every day when we get home from work, so it’s baffling to me that on August 23 there were suddenly multiple mines from which the adult moths had already emerged.


Leafminer #155: Ectoedemia rubifoliella (Nepticulidae), on blackberry (Rosaceae: Rubus allegheniensis).  I found several already vacated mines of this moth in the backyard on August 23. This one shows the semicircular exit slit nicely:


Leafminer #156: Astrotischeria solidagonifoliella (Tischeriidae), on Canada goldenrod (Asteraceae: Solidago canadensis).  I found a single young mine of this moth not far away, less than 1 cm long at this point.


In the backlit view you can see that there is a little frass in the initial linear portion, but the mine is otherwise clean because the larva has been pushing the rest of its frass through a tiny hole in the underside of the leaf.

Leafminer #157: Nola cilicoides (Nolidae), on fringed loosestrife (Primulaceae:  Lysimachia ciliata).  I’ve been watching for mines of this species for several years now without success, and then I happened to spot one behind the chicken house on the evening of the 23rd when I wasn’t even looking.


This is the only nolid moth known to mine leaves, and I might have overlooked it in Leafminers of North America if I hadn’t spent a few months working in the office of the Massachusetts Natural Heritage & Endangered Species Program. Bryan Connolly, then the state botanist, mentioned it to me at some point; he and Dave Wagner had published a paper detailing its natural history*. Young larvae mine leaves in August, at least in some cases exiting to window-feed on the lower leaf surface (as is evident in the lower right portion of the above photo). They then spin small cocoons between two overlapping leaves, where they remain inactive for nine months. In spring and early summer, they bore into young stems, later feeding on flower buds, flowers, and young leaves, which may be loosely tied with silk. When finished feeding they spin cocoons along the stems, and adults emerge a week or two later.

The larva by the chicken house had molted at least once before exiting its mine, leaving a head capsule dangling from the hole it chewed in the lower epidermis.


Leafminer #158: I’m thinking this moth I found flitting around the bathroom on the night of August 23 is Caloptilia hypericella (Gracillariidae), although it wasn’t as shiny as that species typically is. I guess I’ll have to look for mines on the St. John’s-wort in the yard to confirm, especially since the European Hypericum perforatum (the only St. John’s-wort around) isn’t a known host for this species.


On the evening of August 24 I spotted the first couple of Brachys aerosus mines on a blackish red oak in the lower nut orchard, after having seen adults there way back on May 26.


When I went back to take the above photos the next day (note the big, shining eggshell on the upper leaf surface, and the stringy frass in the backlit view), I also found very young mines of…

Leafminer #159: One of the many oak-feeding Cameraria species (Gracillariidae).  The mine below was less than 4 mm across.


On August 25 I went out to document the latest addition to the list and paused for a quick photo of these ambush bugs lurking among goldenrod flowers:


What I was actually heading out to photograph was, admittedly, much less photogenic.

Leafminer #160: Zeugophora sp. (Megalopodidae), on willow (Salicaceae: Salix sp.).  I haven’t yet tried to identify this willow, which came along with a little swamp azalea we planted in the backyard this spring.


I’ve never found a Zeugophora mine on willow before, but these beetles also mine in Populus leaves, and the larva in this mine might be Z. varians, which I reared last year from quaking aspen leaf mines collected the previous August 24 in the woods right behind our house:


The lilac by our front door has yet to reveal a single leaf mine of Gracillaria syringella (Gracillariidae), even though the lilacs along the road by our neighbor’s house were completely covered with them this spring. But it did provide a place for this sleepy little spring peeper to rest.


And now it’s time to head out for more dragonfly surveys, so I’ll leave you with this shot of Julia showing off the aptly named “tall blue lettuce” (Asteraceae: Lactuca biennis) that’s growing by the vegetable garden fence—no doubt doing so well because the seed that gave rise to it happened to land right next to the compost bin.


Oh yeah, that reminds me that I’m also supposed to be listing the plants in the yard we’ve eaten this year. Let’s see…

106. Elderberry (Adoxaceae: Sambucus nigra) – fruit
107. Fennel (Apiaceae: Foeniculum vulgare) – petioles/leaves
108. Beach plum (Rosaceae: Prunus maritima) – fruit
109. Peach (Rosaceae: Prunus persica) – fruit
110. Good-king-Henry (Amaranthaceae: Blitum bonus-henricus) – leaves

* Wagner, David L. and Bryan Connolly. 2009. Pithing and mining by a punkie: the unusual feeding strategies of Nola cilicoides (Grote, 1873) (Noctuidae: Nolinae). Journal of the Lepidopterists’ Society 63(1): 48–51.

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Return of the Tiny Silk-spinning Wasp

Five years ago I wrote about the discovery of a little wasp in Mexico and Brazil that apparently spins silk over stink bug eggs after inserting its own eggs in them. A few days later I made a follow-up post with a few more photos from Brazil, reporting that Mike Gates had identified the wasp as a Neorileya species (Eurytomidae—in the first post it was misidentified as a pteromalid). He had never heard of Neorileya producing silk, and was interested in more concrete proof that this wasp was actually responsible for the silk.

Well, this week Kel Silva, who sent me the previous photos from Brazil, passed along a couple of videos of one of these wasps, taken by her friend Giovane Proença:



Seems pretty conclusive to me. Here’s a photo Giovane took of the scene with an American quarter for scale:


And a photo of another silk-covered stink bug egg mass from Brazil, this one taken by Jhonatan Santos:


As far as I know, no one has yet collected one of these wasps, so their exact identity is still unknown, if they in fact belong to a species that has been given a name. The function of the silk is presumably to make it harder for other wasps to lay eggs in the parasitized stink bug eggs, thus parasitizing the parasitoids.

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The Yard List(s), Part 22

Looks like a correction is in order! Back on July 20, I found the leaf mines below on a summer grape (Vitaceae: Vitis aestivalis) vine growing in the narrow space between the upper vegetable garden and the arborvitae hedge. I identified them as the work of “Antispilaoinophylla (Heliozelidae), noting that the genus of this moth would likely have changed by the next time you heard from me.  


I made that identification based on statements by van Nieukerken et al. (2012) that there is no evident initial linear portion in mines of the species (plural) currently known as Antispila isabella. In transmitted light, it is clear that each of these mines begins with a narrow, dark line along one of the major veins, before suddenly expanding to a blotch that ultimately obscures most of this linear portion.


And yet: by July 26, all three larvae had cut out their pupal cases, revealing themselves to be Antispila in the strict sense.


The prominent central, longitudinal ridge in the pupal case is unique to Antispila, at least in North America.


If I had found these mines already vacated (in which case the pupal cases would have been formed on the ground and I never would have seen them), I still would have recognized them as Antispila “isabella” because of the relatively large, nearly circular holes. I’m using quotes here because both DNA and morphological evidence indicate there are at least two different species going under this name. But that’s a problem for another time. For now, we’ll call leafminer #139 for this year’s yard list Antispila isabella. Here’s an adult that emerged on July 10 from a leaf mine Julia and I collected on August 29 last year at Black Rock Forest in New York—clearly a species with just one generation per year, especially given that I removed the pupal case from winter refrigeration way back in February.


Meanwhile, on July 22, I found two more grape “Antispila” mines, this time on riverbank grape (Vitis riparia) in the “lower nut orchard.”


Although it wasn’t visible to the naked eye, in these photos I can see that the mines likewise began with a short linear portion, but in this case with an even narrower, broken line of frass, rather than being frass-filled as in the mines on summer grape. These larvae likewise began cutting out their pupal cases on July 23, with the second one finishing on the 26th.


The cut-outs are small and narrow, and the surfaces of the pupal cases are perfectly flat:


This tells us that the riverbank grape miners are “Antispila” oinophylla, the species I had originally assumed the summer grape miners to be. As of today, the correct name for this moth is Aspilanta oinophylla, thanks to a paper Erik van Nieukerken and I coauthored. I have never reared this species, which is why I collected the mines I found in my yard, but the adult is externally indistinguishable from the Virginia creeper leafminer Antispila Aspilanta ampelopsifoliella:

Parthenocissus, MA (Pelham) adult-001

If you see an “Antispila” with that silvery spot near the tip of the wing, it’s really an Aspilanta. (Incidentally, the name Antispila refers to the pattern of opposing spots on the wing, which is common to both genera; “Aspilanta” is just an almost-anagram of Antispila). Unfortunately, there is one Aspilanta species that doesn’t have this spot, so if the spot is missing, distinguishing the two genera requires rubbing off the moth’s scales to examine the wing venation (or dissecting it to examine its genitalia, or analyzing its DNA… though as far as we know, if the moth lacks that spot and has no white tips on its antennae, it is a true Antispila). Fortunately, the difference in the pupal cases is 100% consistent, so if you’re trying to identify a moth you’ve reared, you’ll have no problem getting it to genus.

And so, leafminer #144 for this year’s yard list is Aspilanta oinophylla. Although, in the interest of full disclosure, there is another unnamed grape-feeding Aspilanta that is externally identical to A. oinophylla but with a different DNA barcode. Its genitalia have not yet been examined and the characteristics of its leaf mine are unknown, so I guess I can’t swear that it isn’t the species I have in my yard. So far that one is only known from Connecticut and Florida.

Before I get to the latest additions to the list, there are a few other updates.

I had hoped to rear some adult moths from the three sweetfern leaf shelters of Parornix peregrinaella I collected back on July 7, but instead 11 of these eulophid wasps (probably a Chrysocharis species) emerged from them between July 22 and 26.


On July 11, I had found this solitary sawfly larva on the planted shadbush by my garage…


…and I wasn’t sure if it was a new species for the yard or the same one I had found on the other side of the house a month earlier (sawfly #14):


The July 11 larva kept nibbling away for a couple of weeks, and its head never turned brown to match the otherwise similar larvae I had found before, but it also never grew noticeably; it started to look sickly, and eventually died. I kept it for a bit longer to see if any parasitoids would emerge, and on July 28 this eulophid appeared (I believe it belongs to the subfamily Tetrastichinae):


I couldn’t find any evidence that it had emerged from the sawfly larva, so I took a close look at the leaves in the vial and discovered that it had emerged from the pupa of another eulophid, which was lying in one of the sawfly larva’s previous feeding sites. So evidently its host eulophid did feed as a larva on the sawfly larva, but the sawfly larva kept feeding for a while after the parasitoid larva had left it.  The emerging adult hyperparasitoid chewed a hole in the dorsal surface of the primary parasitoid’s pupa.


I’ve found eulophids emerging from braconid cocoons several times, but this is the first time I’ve personally found conclusive evidence of a eulophid parasitizing another chalcidoid.

You may remember the stem miner (#131) I found on Canada goldenrod on July 20. I wrote: “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…”  Well, on July 29 I took a close look at that stem and found that the larva had pupated, showing itself to be an Ophiomyia rather than P. arctica.


The adult emerged on August 3—alas, a female, so we’re stuck with “some unknown Ophiomyia” until someone can rear a male from one of these mines.


I haven’t been able to spend much time in my yard lately, for reasons I’ll explain later, but I’ve managed to add a few more leafminers to the list.

Leaf (stem) miner #145: Ophiomyia sp. (Agromyzidae), on wild lettuce (Asteraceae:  Lactuca canadensis). On July 28 I found a couple of aborted mines on a plant that popped up along the driveway among the perennials we’ve planted there to make it appear to passersby that we have a “normal” yard. I reared a bunch of males of this species last year, so I’ll be able to put a name on it eventually. This is the “scab”-forming species I mentioned in an earlier post, first noticed by John van der Linden.


Leafminer #146: Agromyza parvicornis (Agromyzidae), on corn (Poaceae: Zea mays). I found the first mine of this species on the same day, starting as a linear track on the upper leaf surface and then switching to the lower surface where it formed an elongate blotch.


On a nearby corn leaf there was a fall webworm sitting on the cocoon of a microgastrine braconid that had emerged from it. I probably should have collected that to rear, but I was feeling a bit overcommitted right then.


On July 31 I found the time for a more thorough survey of the yard’s latest arrivals and turned up three more species.

Leafminer #147: Liriomyza sp. (Agromyzidae), on white snakeroot (Asteraceae: Ageratina altissima). If you were relying on Tracks & Sign of Insects for leaf mine identification, you would conclude that this mine is the work of L. eupatoriella. It turns out there are at least three different Liriomyza species forming linear mines on white snakeroot, and it’s unclear at this point whether their mines can be reliably distinguished. The mines I’ve collected in the woods behind my house did indeed produce adults of L eupatoriella, but this mine I found under one of the young butternut trees in the “nut orchard” could well belong to another species, which may or may not be L. cracentis.


Leafminer #148: Stigmella nigriverticella (Nepticulidae), on the same blackish red oak sapling that has already contributed two other leaf-mining moth species this season. Mines of this species differ from those of other oak-feeding Stigmellas in being filled with frass throughout their length.


Leafminer #149: Stigmella sp. (Nepticulidae), on black birch (Betulaceae: Betula lenta). This is the most common nepticulid on black and yellow birches in my experience, but it doesn’t have a name yet.


Leafminer #150: The mystery agromyzid on apple mint (Lamiaceae: Mentha suaveolens) I mentioned in my previous post. I’ve been keeping an eye on the apple mint and on August 6 there were a bunch of new mines in evidence, some of which clearly had larvae inside.


I’m now convinced they can’t possibly be weird mines of Calycomyza menthae; they don’t match any known North American mint miner. It occurred to me to check the European leafminer website—having already found one previously undocumented immigrant on a mint (oregano) in my yard this summer—and they seem to be a perfect match for Phytomyza tetrasticha: they begin with a compact brown spiral, followed by a convoluted, intestine-like track with conspicuous feeding lines. Here’s a recently completed example:


However, I hesitate to say the apple mint miner is in fact Phytomyza tetrasticha because the three larvae that have emerged so far all formed pale brown puparia, not black like the one shown on the European website. They’re also a bit more elongate. Needless to say, I will keep monitoring the apple mint patch until I’ve secured some adult males of this species to confirm its identity.


One other recent development is that between August 6 and 8, five adults have emerged of sawfly #35, the gregarious Arge larvae I found defoliating the shadbush by the garage on July 11. Three males…


…and two females.


And finally, the latest additions to the list of plants I’ve eaten in the yard this year:

94. Choke cherry (Rosaceae: Prunus virginiana) – fruit
95. Green bean (Fabaceae: Phaseolus vulgaris) – fruit
96. Groundcherry (Solanaceae: Physalis sp.) – fruit
97. Lemon balm (Lamiaceae: Melissa officinalis) – leaves
98. Anise hyssop (Lamiaceae: Agastache foeniculum) – leaves
99. Cucumber (Cucurbitaceae: Cucumis sativus) – fruit
100. Cilantro (Apiaceae: Coriandrum sativum) – leaves
101. Huckleberry (Ericaceae: Gaylussacia baccata) – fruit
102. Bell pepper (Solanaceae: Capsicum annuum) – fruit
103. Corn (Poaceae: Zea mays) – seeds
104. Dill (Apiaceae: Anethum graveolens) – leaves
105. Rutabaga (Brassicaceae: Brassica napus) – roots

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