More and more

Adults have emerged from another 20 or so overwintered vials and jars since my previous post. Here are some more that came from larvae collected right in my yard.

On June 21, I collected these larvae from one of our cultivated hazelnuts (Sawfly #27 in this post):


Thirteen of them reached maturity and burrowed into a jar of soil by the end of the month. Over the past few days, three of these wasps have emerged from the soil:

They appear to be braconids in the genus Ichneutes (thanks to Gergely Várkonyi for the ID). In my decade of rearing all sorts of herbivorous insects, to my knowledge I have only previously reared two braconids in the subfamily Ichneutinae, both from tiny leaf-mining moths. The ichneutines that parasitize sawfly larvae oviposit in their hosts’ eggs, or sometimes in young larvae, but their offspring wait until the sawfly larvae have finished feeding and spun their cocoons before doing most of their own feeding and ultimately killing their hosts. Did the mother Ichneutes manage to insert an egg into every one of these hazelnut larvae (or the eggs from which they hatched) before I got to them? Time will tell.

Last year’s Leafminer #89 was Stigmella prunifoliella (Nepticulidae), which I identified based on a predated leaf mine on black cherry that I found on June 26. On September 28 I collected a few leaf mines on peach that I presumed were the work of this species, but I wanted to make sure since it hadn’t been documented on peach before. Here is a very early mine, with the green larva munching away inside…

…and here is a vacated mine three days later…

…and here is the adult that emerged on March 22:

Virtually all of the insects I have emerging right now are univoltine species, with just one generation per year, and larvae found only in spring or early summer. With the exception of some parasitoid wasps, Stigmella prunifoliella is the only multivoltine species that has made an appearance so far.

Last year’s Sawfly #25 was a larva I found in June on white avens (Rosaceae: Geum canadense)…


…and within a few days I found larvae that I thought might be the same (though I noted a behavioral difference), feeding on leaves of cultivated strawberries.


On March 22, an adult emerged from each jar—strawberry…

…and avens:

I still think they might be the same! I believe the only sawfly in North America with free-living larvae that have been found on avens is Pristiphora pallidiventris, and this clearly isn’t that. I’m guessing this is one of the six species of Allantus, Empria, and Taxonus that are known to feed on strawberry, but I won’t worry about which species that might be just yet. [Edit, 3/26/2021: Marko Prous says these are “Empria (maculata maybe, which seems to be a complex of several species)”.]

Early last June I pointed out a gall on a fox grape leaf made by Heliozela aesella (Heliozelidae), an odd species in a family that (in North America, anyway) is otherwise composed of leafminers. Here is a better look at one of the galls, viewed from above and below:

The mature larva cuts out an oval chunk from the upper surface of the gall and wraps it around a tube of frass held together with silk, then wanders off, dragging this portable burrito-house until it finds a suitable place to overwinter, at which point the gall chunk becomes its cocoon.

On March 22 two of these emerged as adults:

While I was putting together my “Bugs in Winter” course, I cut open some goldenrod stem galls from my yard so I could include photos of their interiors in one of my slideshows. When I cut open this gall of Epiblema scudderiana (Tortricidae) in January…

…I found the live moth larva still inside (as would be expected for this species), visible in the photo below through a little nick in its protective silken tube.

Since it would likely be doomed if I put the opened gall back outside, I instead put the gall in the fridge along with the other overwintering bugs, and took it back out with the rest of them on March 1. Alas, it turned out the larva had already been doomed by parasitoid larvae living inside it: eleven of these microgastrine braconid wasps emerged on March 22:

Based on this study of parasitoids of Epiblema scudderiana, these wasps might be Apanteles cacoeciae, which was the only microgastrine and the only gregarious parasitoid associated with this moth in western Pennsylvania.

Back on May 29, I found my second type of sawfly larva for the year, a member of the Acordulecera dorsalis complex (Pergidae) feeding on red oak.


The seven larvae I collected all burrowed into soil by June 3, and three adults emerged on March 23 and 24.

All the ones from my yard, and another five I reared from a red oak sapling across the road, look like the one above—not as fancy as the ones I reared from the same host in Connecticut five years ago:


And finally, there was the leaf-rolling sawfly larva (Pamphiliidae) that I found on June 7 on one of the shadbushes we planted by our garage:


The adult emerged yesterday, a lovely wasplike creature:

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First sawflies of the season!

I took all my overwintering larvae and pupae out of the fridge on March 1, and so far two agromyzid flies, two scathophagid flies, two braconid wasps, two eulophid wasps, and seven sawflies have emerged as adults. Apart from the braconid and eulophid parasitoids, these are all species that have a single generation per year, with larvae that are only active for a few weeks in spring or early summer, so every individual that emerges nearly a year later feels like a major triumph.

The first sawfly appeared on March 12, from a jar of soil into which at least seven larvae had burrowed between June 18 and July 11 of last year. I had collected three larvae on June 13 from some field horsetails (Equisetaceae: Equisetum arvense) in the ditch across the road from my house, and several additional larvae appeared in the jar over the next couple of weeks—they had been either eggs or tiny larvae that I didn’t notice when I collected the three larger larvae. Here’s what one of them looked like on June 15:

And one on June 18:

This winter, between putting together my “Bugs in Winter” online course, revising portions of Leafminers of North America, peer-reviewing hundreds of pages of manuscripts written by other leafminer researchers, and getting a few papers of my own ready to submit, I managed to make reasonable progress on my guide to sawfly larvae, including writing the section on horsetails. What I learned as I put together the horsetail section is that Leblanc & Goulet (1992) published a key to larvae they had raised from eggs laid by six species of Dolerus (Tenthredinidae) they had collected in eastern Canada and put in cages with field horsetail plants. Twenty other Dolerus species and subspecies in North America are likely to feed on horsetails because they belong to subgenera that have been exclusively associated with horsetails in North America and Europe (mostly as caught adults), but the larvae are completely unknown for all of these. So as far as I know, this adult that emerged four days ago is the first North American horsetail-feeding sawfly that anyone has actually reared from larva to adult:

I haven’t made any attempt to identify it yet, but the larvae don’t match any of the six species described by Leblanc & Goulet, so it seems like some progress has been made here. I think they are the same as sawfly #19 from last year’s yard list, which was likewise found on field horsetail, and I think they’re also the same as the larvae I found on wood horsetail (E. sylvaticum) by the beaver pond down the hill from my house—an adult emerged from that jar today, but I haven’t had a chance to photograph it yet.

I fully expected the first sawfly adults to emerge to be Dolerus, since I’ve seen adults of this genus as early as March under natural conditions. I also expected that other early emergences would include some of the first larvae I found last year. On May 31, I collected five larvae like this from a little aspen sapling in my front yard (sawfly #3 from the yard list):


At the time the sapling was unambiguously a bigtooth aspen (Salicaceae: Populus grandidentata), but over the course of the summer it transformed into an unambiguous quaking aspen (P. tremuloides). I haven’t yet attempted to make any sense of the 20+ North American sawfly species that are known to feed on Populus, but as I mentioned when I first found these larvae, I suspect the genus is either Euura or Nematus. Whatever species this may be, I now know what the adults look like, because all five of them emerged on March 14 and 15.

Sawflies overwinter as larvae in their cocoons, waiting until spring to pupate. So apparently these two species can be convinced that spring has arrived after being exposed to warmer temperatures, then pupate, transform to adults, chew their way out of their cocoons, and claw their way to the soil surface, all in the space of 11 to 14 days.

With any luck, there will be more updates soon!

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Introducing Haplopeodes loprestii

This leafminer business all started nearly ten years ago, in the fall of 2011. I had become fascinated with these tiny creatures while I was writing Tracks & Sign of Insects and Other Invertebrates a few years earlier, but it was after visiting Nantucket for the first time, from September 7 to 11 of that year, that I decided to embark on a quixotic quest to create a complete guide to the leafminers of North America, so that I could fully identify everything that I had found there.

During that visit, I met an enthusiastic intern at the Maria Mitchell Association named Eric LoPresti. It was when I returned in November to present my findings at the Nantucket Biodiversity Initiative’s biennial research conference that I met his fellow intern Julia Blyth (now the museum’s consulting collections manager), who has joined me in all my subsequent surveys of the island, as well as on leafminer expeditions all over North America.

In October 2012, in the middle of a three-month voyage around the US, Julia and I explored northern California with Eric for a few days during his first year as a grad student at UC-Davis. In 2017, toward the end of his time there, he invited us out to play in the desert super bloom in southern California, and we spent a week leafminer-hunting with him there and in Arizona. Eric has a knack for finding interesting new mines, and once I tell him something is interesting, he keeps bringing me more and more of it until I have to tell him to stop. One day we discovered previously undocumented leaf mines on sand verbena (Nyctaginaceae: Abronia), a plant for which he has undying enthusiasm, and I thought it would be perfect to name the species after him if I managed to rear it.

I did manage to rear it, but it turned out just to be a new host family for the well-known and extremely polyphagous species Liriomyza trifolii (Agromyzidae).

Later, Eric gave me some leaf mines on Fagonia laevis (Zygophyllaceae), a small-leaved desert plant related to creosote bush. No leafminers were known to feed on this plant, so I was excited to see what the larvae would turn out to be.

They were clearly moth larvae, but to say anything more specific I would have to rear them…

…which I succeeded in doing, but they turned out to be some kind of Gelechiidae in the tribe Gnorimoschemini, a particularly difficult group, so I’ll need to enlist a specialist to figure out what they are more specifically.

But in the meantime, two tiny fly puparia had appeared in the rearing container, and I segregated them out to see what would emerge from them.

Two months later, this female fly appeared…

…and two weeks after that, this male:

Were these weird-looking things agromyzids? I wasn’t sure, but it seemed like they might be, so I threw them in with a big batch of agromyzids I sent to Owen Lonsdale, and when he got a look at them, he reported that they were a new species of Haplopeodes. This is an agromyzid genus I’d never met in person before; in North America there are just four other known species, which are leafminers of Amaranthaceae, Portulacaceae, and Solanaceae and are not known to occur in the Northeast.

Unless you skipped past the title of this post, you won’t be surprised to learn that Owen and I named the new species Haplopeodes loprestii, in a paper that was published this week*. The other twelve species described in this paper were reared by our three coauthors: John van der Linden, Tracy Feldman, and Mike Palmer. Coincidentally, last fall Eric moved to Oklahoma, where he is now an assistant professor at Oklahoma State University, filling the position that became available when Mike Palmer retired and moved to Oregon.

So what does Haplopeodes loprestii do for a living? It’s probably a leafminer, since all its known relatives are, but since the rearing container included Fagonia stems and fruits as well as leaves, it’s conceivable that the larvae feed in one of these other structures. The leaves are so small that if there were two different types of mines in them, it would have been hard to notice—and I didn’t know to look until the leaves were too far gone to try. Always more to learn!

* Eiseman, Charles S., Owen Lonsdale, John van der Linden, Tracy S. Feldman, and Michael W. Palmer. 2021. Thirteen new species of Agromyzidae (Diptera) from the United States, with new host and distribution records for 32 additional species. Zootaxa 4931(1): 1–68.

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A couple of quick end-of-year announcements:

The online “Bugs in Winter” course I mentioned a few weeks ago is now full, because a limited number of people can participate in the live discussion sessions. However, the course content is now also available as an “on-demand” purchase; the only difference for people doing it this way is that they won’t be able to tune in to the live sessions (but they will still be able to watch recordings of them afterwards). As always, I will be available to answer any questions by email. For more information about the course, see this page.

The other, and more time-sensitive, announcement is that I’ve got some 2021 Leafminers of North America wall calendars available. These are normally reserved for my most generous patrons, but I will send one to anyone in the US or Canada who makes a contribution of $30 or more by midnight today (eastern time). $30 is the price I pay WordPress each year to keep this blog free of ads, so not a bad deal if you ask me! To make a contribution of any amount—which will go to support my continuing research into leafminers, sawfly larvae, and other obscure but fascinating herbivorous insects—you can use this link.

This year’s calendar includes some photos of leaf mines and some photos of adult insects I’ve reared from them. The cover photo (above) shows a white oak leaf with mines of three different moth genera: Stigmella (Nepticulidae), Cameraria, and Phyllonorycter (Gracillariidae).

Thanks everyone for your interest in my natural history ramblings, and I’ll see you next year!

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The Yard List(s), Part 32

As I do every winter, I’ve lately been picking away at organizing all the photos I’ve taken over the past year, and the other day I discovered that this blog’s running list of leafminers in my yard omitted a species I found back in July. It should have been #119 for the year, but we’ll call it…

Leafminer #209: Lyonetia prunifoliella (Lyonetiidae). On the evening of July 8, I collected some fresh pin cherry leaves for my attempted rearing of leafminer #70 (which I believe was Caloptilia invariabilis, but only braconid wasps ever emerged). One of the leaves had this vacated mine on it:

The fecal pellets strung like pearls on a strand of silk, dangling from a hole in the lower epidermis at the edge of the mine, easily identifies this as the work of L. prunifoliella. Young larvae of this species make narrow, linear mines with frass in a dotted central line, but this larva had wandered from its original leaf before establishing this blotch mine. Here’s an adult I reared from a pin cherry leaf I collected while teaching my leafminer course at the Eagle Hill Institute in Maine in the summer of 2019:

Might as well take care of some other loose ends while I’m at it.

Leafminer #210: Ophiomyia euthamiae (Agromyzidae), on grass-leaved goldenrod (Asteraceae: Euthamia graminifolia). This is another species (along with O. parda and Phytomyza erigeronis) that has my front yard as its type locality, and I was watching for it all year until I finally found a few mines at the southeast corner of the yard on October 23. The entire type series was reared from mines I collected in October 2015, so maybe this species just has one generation per year and larvae are only active in the fall, but the adults emerged from those mines three to six weeks after I took them out of the fridge in spring 2016, so one wonders what the adults are doing all summer. I guess it’s possible the eggs are laid in spring and early summer but don’t hatch until the fall, but as with so many things, further investigation is needed to figure out what’s really going on.

This species makes linear mines that are initially on the underside of the leaf…

…but then switch to the upper surface, where the blackish puparium is ultimately formed (upper left in the photo below).

Here’s another example from 10/23/2020:

And here’s the holotype from five years ago:


Once it started getting all snowy I figured that was about the end of this year’s leafminer list, but then on December 14 it occurred to me to check the young conifers at the edge of the woods.

Leafminer #211: Coleotechnites sp. (Gelechiidae), on hemlock (Pinaceae: Tsuga canadensis). There are two species with identical habits, of which one has green larvae (C. apicitripunctella) and the other has brown larvae (C. macleodi). The larva mines in one or two needles in the fall, overwintering in its last mine, and then in the spring it ties together several needles with silk, at first mining in them and later feeding on them externally. I haven’t yet found a larva inside a mine, but here is an abandoned group of tied and mined needles from last spring.

Seven years ago I managed to rear this adult of the brown hemlock needleminer:

Leafminer #212: Argyrotaenia pinatubana (Tortricidae), on white pine (Pinaceae: Pinus strobus). The larva of this species, the “pine tube moth,” ties a bunch of pine needles into a tubular bundle and then mines into several of them. It forms several of these bundles throughout its life, and in the last one, rather than mining the needles, it lines the inside of the tube with silk and then starts cutting off the ends of the needles one by one and then munching on them within the shelter of its tube. As with the hemlock needleminers, I haven’t yet found (or looked for) the young larvae, but the cut-off tubes of mature larvae are a common sight.

I was also keeping track of all the plants I ate in my yard this year, so here’s the final report on those.

123. Foxtail grass (Poaceae: Setaria pumila) – seeds
124. Black birch (Betulaceae: Betula lenta) – twigs (tea)
125. White pine (Pinaceae: Pinus strobus) – leaves (tea)
126. Medlar (Rosaceae: Mespilus/Crataegus germanica) – fruit
127. Arborvitae (Cupressaceae: Thuja occidentalis) – leaves (tea)
128. Lemon (Rutaceae: Citrus × limon) – fruit
129. Poppy (Papveraceae: Papaver somniferum) – seeds
130. Hemlock (Pinaceae: Tsuga canadensis) – leaves (tea)

The 130 plant species I ate belonged to 47 different families, the most important being Asteraceae (14 species), Rosaceae (13 species), and Brassicaceae (10 species). The 212 leafminers (representing 18 moth families, four families each of flies and beetles, and two sawfly families) collectively fed on plants in 52 different families, but no one species was found on more than two plant families. As with me, Asteraceae was the most popular family with the leafminers, supporting 39 species, followed by Rosaceae (35 species), Fagaceae (18 species), and Betulaceae (15 species). The 49 different types of sawfly larvae I found (including both leaf-mining and free-living species) were found on plants in 16 families, with 13 of them on Rosaceae, 11 on Betulaceae, four each on Fagaceae and Salicaceae, and just one on Asteraceae. For whatever that’s worth.

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Summer Strolls in Streams, Part 3

I’d never seen these “hammerhead flies” (Diopsidae: Sphyracephala) before this summer, but I encountered them several times in August while walking along streams. I’m not sure why they would be associated with streams specifically; apparently the larvae feed on decaying vegetation, and according to Steve Marshall’s Insects: Their Natural History and Diversity, adults are found in “swampy areas”; one of the two North American species, S. brevicornis, “overwinters in the adult stage and can often be found around skunk cabbage in early spring or late fall.” That’s all the information I’ve found about them so far. Here are some congregating on a leaf overhanging the Mill River on August 20:

Maybe someday I’ll meet them when I have a proper camera/lens in hand, but for now, this is what we get.

Despite its limitations, I’m loving this camera’s (the Olympus Stylus TG-4) ability to take pictures underwater. I wish I’d had back when I was spending every spring conducting surveys of vernal pool amphibians. Here’s a crayfish in another stretch of the Mill River, also on August 20:

Later that day, on the North Branch of the Manhan River, the pupal skin of a big crane fly (Tipulidae) poking out of the liverwort-covered streambank:

This crane fly I found ten minutes later may or may not have been what emerged from that pupa:

On the way back to the car from that site we met this American pelecinid wasp (Pelecinidae: Pelecinus polyturator). The larvae of this species are parasitoids of the grubs that turn into junebugs, or May beetles, or whatever you want to call them.

There was a little stream in Whately that was almost totally dry on our second visit, but when we came for our final visit on August 20 there was more water than ever. Lots of millipedes were congregating on emergent stones, seeking higher ground…

…and some that had chosen the wrong stones were still clinging to them underwater.

This group was joined by a slug. I don’t know how long these things can survive underwater, but it seemed like the water level must have gone up shortly before we arrived.

August 21, along the Middle Branch of the Westfield River: a dobsonfly egg mass attached to an overhanging boulder.

And a nice bit of exposed bedrock in the riverbed.

Later that day, I found a few larvae of the sawfly Tenthredo grandis (Tenthredinidae) on their host plant, turtlehead (Plantaginaceae: Chelone glabra), along the shore of the Whiting River.

I hadn’t seen one of these beauties in 16 years, so of course I brought a couple home for some better photos.

August 22, along Clesson Brook: a caddisfly infected with the fungus Erynia rhizospora, which causes its hosts to die plastered to rocks overhanging streams, aiding the pathogen in spore dispersal.

This crane fly has succumbed to a similar fate, presumably infected by a different fungus that is specific to crane flies.

And this fungus victim appears to be a yellowjacket or something like that. There seems to be a fungus for just about everybody, as evidenced by this gallery I’ve been maintaining on BugGuide over the years.

August 24, on the East Branch of the North River: a boulder that has been popular with the dobsonflies over the years. Each of the ~30 white rings is the remnant of an egg mass (like the one above) that contained up to 1000 or so eggs.

Here’s a close-up of the main cluster:

Please correct me if I’m wrong, but I’m thinking this is the shed skin of a caddisfly pupa that wriggled out of its case and crawled up the side of a boulder so that the adult could be out of the water when it emerged.

Later that day, somewhere in Rowe: eggs of a caddisfly (Limnephilidae) in a jelly matrix, deposited on a mossy bank overhanging a stream, into which the larvae will drop when they hatch.

Also a red eft (the terrestrial juvenile stage of the eastern newt)…

…and a footprint of a small black bear.

As it happens the next site we visited that day was the Cold River in Florida, where we’d seen a bear during our first visit. This is the slope we’d watched the bear scrambling up a few weeks earlier:

August 26, another big footprint—this one left by a beaver on the bank of the Konkapot River.

A mayfly resting by the Green River in Great Barrington (I’m told it’s Isonychia bicolor, same genus as the exuviae in my previous post):

And this was news to me: a native insect (the caterpillar of the pearly wood nymph, Noctuidae: Eudryas unio) that feeds on purple loosestrife (Lythraceae: Lythrum salicaria). It also feeds on the native swamp loosestrife (Decodon) and members of the evening primrose family (Onagraceae).

Along a little stream in Lenox, some sawfly larvae devouring a willow leaf (these, too, were added to the menagerie in jars on my desk):

Along the East Branch of the Housatonic River, a black and yellow mud dauber (Sphecidae: Sceliphron caementarium) on its way to daub some mud:

August 28, last visit to the Fort River: Sometimes it was hard to picture how a dragonfly nymph managed to get itself to the spot where I found its empty skin clinging, like this one that was at the tip of a long root dangling over the water:

Along the Middle Branch of the Westfield River, another caddisfly egg mass—this one more recently deposited (in the first one the eggs didn’t look as round because the embryos were pretty far along).

And that’s a wrap! (Well, there were some other interesting leaf mines, but I’ll wait till I have the full story on those.)

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Summer Strolls in Streams, Part 2

For the dragonfly survey this summer, Julia and I selected 30 sites and visited them each three times, so it was a busy six weeks of zigzagging all over the place from Florida to Monterey. (Yes, those are both towns in western Massachusetts.) It was along the Cold River at the Florida site that we got a good look at a bear during our first visit on July 26. When we returned on August 10, we got to see something equally thrilling but on a smaller scale: the intricate net constructed by a net-spinning caddisfly larva (Hydropsychidae). The function of this net is to catch food (algae, detritus, bugs, etc.) as it is swept downstream, so these are only found in reasonably fast-moving streams. I had the camera ready this time, but because the net was just below the turbulent water surface, getting a picture of it in focus was challenging. This is the best shot I (or maybe Julia) was able to manage:

But the camera did a reasonable job of staying in focus when in video mode, so you can get a better sense of the shape of the net here:

There seems to be a little larva in the right edge of the net in addition to the larger larva in the middle, which presumably made the net. Not sure what that other one might be. Here’s another attempt:

Later that day, in the East Branch of the North River in Colrain: Other insects were shedding their skins on the banks and emergent stones besides the dragonflies we were after. Here are the exuviae of a mayfly (Isonychiidae: Isonychia) and three water striders:

And a stonefly:

There is some kind of caddisfly that makes cases out of pebbles and gets together in big aggregations on the sides of rocks—maybe just when the larvae are getting ready to pupate.

A handsome green frog:

August 11, along a muddy stretch of the Konkapot River: a leaf of red osier dogwood with rows of dark spots indicating where sawfly eggs were inserted.

Spotting dragonfly exuviae on vegetation was trickier than on rocks, but I noticed this one’s face peeking out among the pinnae of a sensitive fern frond.

Later that day in the East Branch of the Housatonic River, some artwork created by a bird (heron?) standing on the tops of curved boulders and pooping.

We packed in five sites that day, and at the last one we were rewarded with dinner: oyster mushrooms…

…and chicken of the woods.

Also at this site was a green frog perched atop a tall, steep-sided boulder. I don’t really understand how it got up there.

A fancy adult caddisfly…

…and on the shore, leaf mines of Ophiomyia congregata (Agromyzidae) on rattlesnake-root (Asteraceae: Nabalus). By watching individual plants in the woods behind my house a few years ago, I determined that this the larva of this fly starts mining leaves in midsummer, then overwinters in the crown of the plant, mining into the petioles of new leaves in the spring and ultimately pupating there.

August 13, along the murky Fort River: Leaf mines in beggar-ticks (Asteraceae: Bidens sp.) made by Liriomyza carphephori (Agromyzidae), a species I described with Owen Lonsdale and Tracy Feldman last year. There are three larvae in this leaflet, visible as yellow dots toward the base.

At the same site, some monkeyflower (Phrymaceae: Mimulus ringens) in bloom, with what I assumed at the time was a leaf mine of Ophiomyia mimuli (Agromyzidae), a species I described with Owen Lonsdale two years ago—and I’m still thinking that’s probably right, but later in August I discovered there is another option on this host plant. More on that later…

Later that day, we met this distinctive moss along the Swift River. The auto-ID function on iNaturalist suggests it’s a Fissidens, which seems plausible but I really have no idea.

Okay, that’s how far I got with the photos yesterday. Maybe I’ll finish today?

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Summer Strolls in Streams

Looks like it’s been a month since my last post. In that time I’ve made some great progress on my new guide to sawfly larvae (finished the preliminary literature review and ready to start putting together species accounts); revised and updated another chunk of the leafminer guide (I’ll be sending out the chapters up to and including the legumes shortly); and I’m now putting together an online course about how insects and other invertebrates make it through the winter (you can check that out here—apparently it’s almost full already, but if more people sign up we’ll add another session).

But right now I have to take a little break from all those things to put together a report that’s due at the end of the year. This summer the Massachusetts Natural Heritage & Endangered Species Program hired me and Julia to conduct surveys for an uncommon dragonfly, the ocellated darner. Our surveys consisted of slowly walking up 100-meter stretches of streams and small rivers, collecting all the exuviae (shed skins) left behind by emerging dragonflies when the nymphs crawled out of the water and molted to adults (as shown here). This fall, Julia got to go through all the exuviae we collected and identify them to species, and then enter all our data into a database, and now it’s my turn to work on putting the report together and submitting our data to NHESP. Part of that is going through and organizing all the photos I took of our survey sites. And part of that process is weeding out the “extracurricular” photos. So here’s the first batch.

July 24, Middle Branch of the Westfield River: Cimbex americanus (Cimbicidae), among the chunkiest of all sawflies, rests on a stone at the edge of the river, apparently having just emerged from a harrowing tumble down the river, which claimed parts of its left antenna and wing. This species is known as the “elm sawfly,” but it is actually one of the few sawflies whose larvae feed on foliage of a variety of unrelated trees.

July 27, Whiting River: A leaf of some kind of beggar-ticks (Asteraceae: Bidens) bejeweled with dew, and sporting a leaf-mining larva of a species of Calycomyza (Agromyzidae)—possibly C. avira, which Owen Lonsdale and I described two years ago.

Just a few feet away, some leaf mines on purple-stemmed aster (Asteraceae: Symphyotrichum puniceum) made by larvae of Microrhopala xerene (Chrysomelidae), a striking black beetle with red racing stripes.

And dotted along the shore of that same stretch of river were mines on miterwort (Saxifragaceae: Mitella diphylla) made by what is probably an undescribed species of Phytomyza. (Julia and I collected and reared this species in Iowa last summer but Owen hasn’t had a chance to examine the specimens yet.)

I mostly had been leaving the camera in my backpack at this point in the season, but on this day I decided to keep it in my pocket to get a few pictures of the dragonfly exuviae in situ. The first one I came to was from a nymph that had climbed several feet up a hemlock tree to make its transformation. Some time after the adult had emerged, the shed skin had fallen and become caught in a spider web, and a gypsy moth was now laying her eggs behind it.

This stream had a population of green frogs that liked to hang out on ledges many feet above the water level. There is one tucked into a corner just above the middle of this photo, looking right at the camera.

Here’s how we often found the exuviae: clinging to the mossy ceilings of overhanging rock ledges. If you look closely at this skin you’ll see a little orange gall midge (Cecidomyiidae) resting on its abdomen.

July 27, Hubbard River: At the downstream end of this transect (where I had to stand and hold the measuring tape while Julia measured out 100 meters), there was a lovely sedge-covered island with a big patch of cardinal flower (Campanulaceae: Lobelia cardinalis).

Also on this island was a big witch hazel (Hamamelidaceae: Hamamelis virginiana) covered with galls caused by an aphid, Hamamelistes spinosus. Evidently these galls drip with honeydew, because the bush was abuzz with bees and wasps visiting the galls as if they were flowers. My little pocket-sized point-and-shoot was no match for these bugs that were in constant motion, but the photos below give you some idea. I think this first one is a potter wasp (Vespidae: Eumenes, or so)…

…and there were lots of common eastern bumble bees (Apidae: Bombus impatiens).

After we finished each survey, it was my job to walk transects across the stream and (among other things), at regular intervals, measure the water depth and characterize the substrate. On one of the points along my first transect on August 6, the substrate was a wood turtle! This is another uncommon species that NHESP keeps track of, so I ran the 100 meters back to my backpack to get the camera. I had never used this camera’s underwater mode before, but it went pretty well:

From that point on, I kept the camera in my pocket at all times, so the pictures of miscellaneous bugs and things became more frequent. Had I started doing that a week earlier, I could have also gotten pictures of a bear scrambling up a steep slope overlooking one of the streams we surveyed in the Berkshires.

August 6, North Branch Manhan River: a fishing spider (Pisauridae: Dolomedes vittatus) resting on a vertical rockface.

Hard to appreciate the size of this spider without something for scale:

And a side view reveals that she was carrying an egg sac under her body:

August 9, back on that the stretch of the Whiting River that had all those nice leaf mines and frogs: shortly before we arrived, a wading great blue heron had stepped out of the water and left these wet footprints across a boulder.

Also at that site, I met a strange fly I’d never seen before. I called it a “hammerhead fly,” which turned out to be on the right track: it’s a “stalk-eyed fly” in the genus Sphyracephala (Diopsidae), which is Greek for “hammerhead.” The “stalk-eyed” name is better applied to diopsids found in other parts of the world, as seen in this Wikipedia article.

Later that day, back at the stretch of the Hubbard River with all the cardinal flowers and witch hazel galls: a shed skin clinging to the underside of a totally mossless rock. It’s amazing to me that the nymph was able to cling upside down to this surface at all, let alone stay there for an hour while an adult dragonfly slowly squirmed out of its back, and then continue to cling there as an empty husk for days afterwards.

That’s how far I got as I went through the summer’s photos last night. More to come!

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Fringed Loosestrife Fauna

Fringed loosestrife (Primulaceae: Lysimachia ciliata) is a common plant of moist areas that, I realize now that I’m starting to write this post, I’ve never bothered to photograph. But it has yellow flowers and is related to garden loosestrife; it has nothing to do with purple loosestrife (Lythraceae: Lythrum salicaria). Anyway, five years ago—on September 22, 2015—I was at work doing some botanical something-or-other in a Massachusetts wetland when I noticed what appeared to be leaf mines on fringed loosestrife.

It took a very close look at the lower leaf surface to determine that they were in fact what I call “pseudomines”: rather than feeding between the two leaf epidermises—the definition of leafmining—the larva was feeding externally on the underside of the leaf, but beneath a sheet of silk that to the naked eye appeared to be the loosened lower epidermis of the leaf.

There was a twist though: although the “blotch” in the leaf blade was a pseudomine, the larva was also making a bona fide tunnel in the midrib. The entrance to this tunnel is visible at the left end of the pseudomine in the photo above; in the backlit photo below, the excavated portion of the midrib is transparent, and you can see the larva inside the midrib at the left end of this tunnel.

I tried to rear these larvae to find out what they were, and they eventually transitioned to feeding between leaves that they tied together with silk. I took photos of two of the larvae a month after I collected the leaves, on October 22.

Whether the differing appearance of the two larvae (e.g., the second one has darker spots and a dark prothoracic shield) indicates two different instars or just individual variation, I don’t know. By November 1, at least one of them had spun a silken chamber…

…which I suspect was a shelter in which to overwinter, rather than a cocoon in which to pupate. I don’t remember if any of the larvae survived the winter, but the photo above is the last one I have from this rearing.

This mystery has been bugging me ever since, compounded by my suspicion that this moth may be what V.T. Chambers described as Lithocolletis lysimachiaeella (Gracillariidae) in 1875*. The entire description of that species reads:

The larva is cylindrical and very small. It makes a very small tentiform mine on the under side of the leaves of (Lysimachia lanceolata) the loosestrife. The imago is, no doubt, very small—probably not larger than L. desmodiella, Clem., which is the smallest known species of this genus; but I have not succeeded in rearing it.

He gave no indication of where or when he found these larvae, but it was presumably near his home in Kentucky. When she revised the genus in 1908**, Annette Braun noted that she had never seen a Lithocolletis mine on Lysimachia**, and the species was essentially never spoken of again—until Brower (1984)*** made the baffling claim that three specimens had been reared from beech in Maine. (Some of the obvious misidentifications in his list of Maine Lepidoptera can be attributed to using old keys to identify species that hadn’t yet been described when the keys were written, but what could possibly have led him to believe that this species that was known only from a vague description of a larva was the same one that had been reared from a totally unrelated plant a thousand miles away?) The previous year, Don Davis had listed lysimachiaeella as a species of Phyllonorycter****, but this was based only on the fact that Lithocolletis had been synonymized with Phyllonorycter (though it’s not quite that simple, because Braun’s Lithocolletis subgenera Cremastobombycia and Porphyrosela are now recognized as full genera, and the genus Cameraria—which was named for V.T. Chambers; camera being the Latin word for “chamber”—was designated for “Lithocolletis” species with flat larvae that form upper-surface mines).

There is in fact no reason to believe that what Chambers described was even a gracillariid; just a few years earlier he had dedicated a whole paper to leaf-mining “moths” he had previously written about that had turned out to be beetles*****. There is also a footnote in (I think) one of Lord Walsingham’s papers where he listed some other egregious mistakes Chambers had made in describing new species based only on larvae, but I don’t remember now where I saw that.

Anyway, whether or not my midrib-tunneling loosestrife pseudo-miner is what Chambers called Lithocolletis lysimachiaeella, I’m reasonably sure it’s a moth in the family Tortricidae. A few tortricids in the genus Paralobesia do a similar combination of midrib tunneling and pseudo-mining in leaves of magnolia and tuliptree.

Last fall, on September 17, I found larvae of this mystery moth in Vermont, but I again failed to rear them to adults. I had a hunch that the larvae are immature when they overwinter and resume feeding as leaftiers in the spring, so on May 12 I was excited to see a bunch of tied leaves on the fringed loosestrife growing behind the chicken house.

(The frilly hairs on the petioles, incidentally, are why this plant is called “fringed” loosestrife.) Naturally I stuffed a bunch of these tied leaves in a peanut butter jar to see what the larvae would turn into. Alas, ten days later when I got a look at some of the larvae, I found that they bore no resemblance to the mystery larvae, though they did likewise seem to be tortricids.

At the end of May, the sparkling adult moths began to appear.

Identifying them turned out to be easy. The HOSTS database lists two moth species that feed on Lysimachia ciliata as larvae. One is Nola cilicoides (Nolidae), which I discussed as leafminer #157 in my yard list, and the other is Aterpia approximana (Tortricidae), which is a good match for the moths I reared. Which means, it seems, that nobody knows the identity of the species that was the main subject of this post. There’s always next year, I guess!

* Chambers, V. T. 1875. Tineina of the Central United States. Cincinnati Quarterly Journal of Science 2(2): 97–121.

** Braun, Annette F. 1908. Revision of the North American species of the genus Lithocolletis Hübner. Transactions of the American Entomological Society 34: 269–357.

*** Brower, Auburn E. 1984. A list of the Lepidoptera of Maine–Part 2: The Microlepidoptera Section 2 Cosmopterigidae through Hepialidae. Maine Agricultural Experiment Station Technical Bulletin 114: 1–70.

**** Hodges, Ronald W. (editor). 1983. Check List of the Lepidoptera of America North of Mexico. The Wedge Entomological Research Foundation.

***** Chambers, V. T. 1872. On some leaf-mining Coleoptera. The Canadian Entomologist 4(7): 123–125.

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The Yard List(s), Part 31

The day after I wrote my last post, in which I discussed an oak leafminer I’d previously mistaken for Stigmella nigriverticella and mentioned that I’d been keeping an eye out for leaves with “green islands” blowing onto my driveway from the quaking aspen across the road, I found a couple of leaves that require me to follow up on both of those stories.

Leafminer #206: Ectoedemia sp. (populella group) (Nepticulidae), on quaking aspen (Salicaceae: Populus tremuloides). The storm on October 16 brought the leaf I’d been waiting for:

I wrote about these mines five years ago, but I’ve done some further investigation since then, which is reflected on pp. 1129–1130 of Leafminers of North America. To summarize, there are two species in North America that make identical mines on aspen leaves. The egg is laid on the petiole and the larva mines from there into the base of the leaf blade, where it forms an elongate blotch with frass along the sides. The area surrounding the mine remains green after the rest of the leaf has turned yellow, and the larva continues mining within this green patch after the leaf has fallen to the ground. One of the species that does this is Ectoedemia argyropeza, which is introduced from Europe and is now one of the most common nepticulids in northeastern North America. The adult looks like this:

The other species doesn’t have a name yet. The only reared specimens in existence came from a single tree about a mile down the road from my house, but their DNA matches that of adult moths caught in Alberta, Saskatchewan, and Manitoba. The adult of this undescribed species looks like this:


It is not a Stigmella, as Erik van Nieukerken initially thought based on the above photo; it is an Ectoedemia in the populella group (along with E. argyropeza and E. populella). And although I pointed out some apparent differences between the mines of these two species in my post from five years ago, more recently I collected 100 mined leaves from that same tree and carefully scrutinized each one to make sure the mine characteristics were consistent with those of E. argyropeza. The following spring, dozens of E. argyropeza adults did emerge (including the one in the first photo above), but then a few days after the last one emerged, a dozen or so adults of the undescribed species emerged. So unfortunately it seems that identifying these “green island” aspen mines to species requires either DNA analysis or rearing adults.

Back to the leaf I collected in my driveway four days ago, here’s a view showing the eggshell (far left) and the initial mine in the petiole leading into the blade:

Here’s a backlit closeup showing the small blotch mine within the green island. Nobody seems to be home…

…but these larvae are mostly nocturnal, hiding in the petiole during the day. In the photo below, taken this evening, you can see the larva munching away.

Leafminer #207: Stigmella nigriverticella (Nepticulidae), on red oak (Fagaceae: Quercus rubra). The real one this time. I think I had noticed this mine before (in the shrubby area between the main yard and the “nut orchard”), but had ignored it since I knew I’d already put S. nigriverticella on the list.

I of course have no idea at this point what the adult of the S. nigriverticella imposter looks like, but here is the actual S. nigriverticella reared from the mine on Nantucket shown in my previous post:

Over the weekend I put all of my rearing containers in the little fridge in the basement so I can forget about them for a few months. I checked them all one last time before doing so, and I found two adults of sawfly #41 from pussy willow—a female from one of the hatchlings I’d collected on August 31 (all of the larvae matured and burrowed into soil by September 15)…

…and a male from one of the eggs I’d collected on September 2 (all of those larvae burrowed into soil by September 18).

I also got one last parasitoid for the season, a eulophine eulophid from a Cameraria betulivora mine in a black birch leaf I’d collected on September 27.

Today I was wondering what was going on with those late-emerging sawflies. The vast majority of sawfly species overwinter as prepupae, and I don’t know if any overwinter as adults. But surely there isn’t enough time for another generation to develop before all the willow leaves are gone? I wandered over to the pussy willow shrub that had already endured two generations of sawfly #9, followed by three waves (if not distinct generations) of sawfly #41, the last of which attracted a number of ichneumonids. I didn’t see any activity on the few remaining leaves, but without the distraction of all those sawfly larvae, I noticed for the first time something that had been there all along:

Leaf (stem) miner #208: Marmara salictella (Gracillariidae). This is the type species of Marmara, described from Pennsylvania by J. Brackenridge Clemens in 1863, and one that I haven’t had the opportunity to rear yet. Something to keep an eye on next spring!

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