Back in March, as I was updating my chapter on the plant order Myrtales in Leafminers of North America, I was reminded of a strange little moth that Thomas Irvine had reared four years earlier (in January 2021) from a leaf of Conocarpus erectus (Combretaceae)—known as buttonwood or button mangrove—in the Florida Keys. I had passed the specimen along to Terry Harrison, who dissected it and reported that it was a female with genitalia so nondescript that he couldn’t even place it to family. So I was forced to leave the identification at superfamily Gelechioidea.
In January 2022, Tracy Feldman collected a larva of this species. Here are some photos of the completed leaf mine, larva, and pupa:
For some reason it didn’t make it past the pupal stage. I sent Terry the moldering pupa, which he dissected and determined that it was another female anyway.
However, three months later, David Jeffrey Ringer successfully reared another four adults of this mystery moth, which I was planning to send to Terry or some other microlepidopterist for identification.
One of the more distinctive things about them was their very bushy middle and hind tibiae:
Three years passed, and I hadn’t done anything with them yet. But shortly after I completed the third edition update of the Myrtales chapter this past March, my curiosity got the better of me. I had a look at David’s specimens and determined that there was one male among them. Based only on the general appearance of the pupa, which was naked and attached to the substrate like a tiny butterfly chrysalis, rather than in a cocoon, I guessed that the moth might belong to the family Elachistidae, which in North America is composed mostly of species in the genus Elachista that mine leaves of grasses and sedges. I wrote to Lauri Kaila, the world expert on Elachistidae, and asked if he had any idea what this moth was. He said it reminded him of the mostly Afrotropical genus Urodeta, and that he was coincidentally working with Virginijus Sruoga on a small paper about this genus. He noted, “The male genitalia can vary very much, especially with the shape of their valva, but a good character is that the spines in the gnathos are downward-directed unlike other gelechioids.” He put me in touch with Virgis, who just a few months earlier had published a paper describing the first New World species of Urodeta (from Honduras), including keys to males and females of all the known species.
I dissected the male right away (see this post for a description of what that entails), and sure enough, it did have downward (anteriorly) directed spines on the gnathos! Here’s a photo I took before I stained the genitalia, spread the valvae, and made a permanent slide mount; it shows the tips of the valvae, and the spherical structure between them is the spinose knob of the gnathos.
I took lots of photos from different angles before making the permanent slide mount, which turned out to be critical for making sense of what was going on with the various structures. Here’s the final slide mount, which unfortunately features a big hair that floated over one of the valvae before the Canada balsam dried:
When I ran this through Sruoga’s key to the known Urodeta species based on male genitalia, it took me to the couplet that distinguished the Honduran species from an unnamed Australian species that is known only from male and female genitalia slides (the specimens themselves are lost, so Kaila refrained from giving the species a name in his monograph on Australian Elachistidae). The female that Terry had dissected (and one of David’s females that I dissected) keyed to that same Australian species. Based on Sruoga’s and Kaila’s descriptions and illustrations, the Florida moth clearly did not match either the Honduran species or the Australian species. So I wrote up a description of the Florida species and named it Urodeta conocarpi. The paper was published last week:
Eiseman, Charles S., David Jeffrey Ringer, Thomas Irvine, and Tracy S. Feldman. 2025. A new species of Urodeta Stainton (Lepidoptera: Elachistidae) mining leaves of button mangrove (Combretaceae: Conocarpus erectus L.) in Florida and the Caribbean. Zootaxa 5683(4): 530–542.
Although I’ve now coauthored dozens of new species, this is my first solo species description, and really only the third where I had anything to do with the actual morphological description (the other two were both gracillariid moths, with Don Davis taking care of dissecting and describing the genitalia). It was pretty straightforward, thanks to the groundwork laid by Virgis Sruoga, although when I pulled out my slide of the male genitalia the other day to label it, I was a bit amazed that I had succeeded in dissecting and slide-mounting something so tiny.
In the photo above, the genitalia are the little speck right in the middle of the slide mount. The linear object to the left is the rest of the abdomen—here’s a closer look:
The moth’s wings are about 3 mm long. Here’s the male with its wings spread, before I removed the abdomen:
And here’s an image that I didn’t use in the paper, showing the known distribution of this species based on observations of the leaf mines from iNaturalist:
I’ve got countless other undescribed moths to work on, and I’m looking forward to tackling some of them this winter.
Every month, I take a break from whatever it is I do with the rest of my time, and I spend a few days updating another chapter of Leafminers of North America (now 1700+ pages into the third edition) to send out to subscribers. This month I’m working on Caryophyllales, the plant order that includes things like amaranths, spinach, beets, cactuses, pinks, spring beauties, sand verbenas, four o’clocks, pokeweed, sea lavender, and buckwheats. Updates typically involve new host plants, new natural history information, new mystery leaf mines, and new illustrations, with corresponding changes to the leaf mine keys, gleaned from iNaturalist and BugGuide observations, recent scientific publications, and as yet unpublished discoveries by myself and my collaborators; I also am continually making updates to plant and insect taxonomy, including adding newly described leafminer species. Very rarely does an update involve something that was known before I started studying leafminers, which I had overlooked in my previous editions, but here’s one of those rare cases!
In early August 2022 I was teaching one of my “Tracks and Signs of Insects and Other Invertebrates” courses at the Eagle Hill Institute in Maine, and the class was doing a little exploring along the seashore. I was walking with Bill Buck, who pointed at a little clump of sea-blite (Amaranthaceae: Suaeda sp.) and asked, “Does anything mine in that?”
I had never noticed anything mining in sea-blite, but I said “Let’s see!” and broke off a little sprig to examine. Sure enough, there was something mining in one of the leaves!
From the elongate white egg that was glued to the leaf (a bit right of center in the above photo), I knew this was a fly, and I assumed something in the genus Pegomya (Anthomyiidae), of which most of the leaf-mining species are associated with plants in the order Caryophyllales. For instance, mines of one or both of the species that are notorious pests of spinach, beets, and chard (P. betae and P. hyoscyami) are common on oraches (Atriplex spp.) on the Maine coast. Here’s a close-up of the egg:
I looked around for other mines on sea-blite, to improve my chances of rearing this thing, and I found another similar one (egg at far left)…
…plus something that looked entirely different, with a puparium inside:
It was reddish-brown like a Pegomya puparium but pretty small, and it would be very unusual for a Pegomya larva to pupate in the leaf instead of burrowing into the soil (although doing the latter in the intertidal zone does seem like a dicey proposition). But it’s typical for a Pegomya larva to start out making an unobtrusive linear mine, then form a blotch that pretty much destroys part or all of the leaf, sometimes popping out and mining into a fresh leaf. I put the mined leaves in a vial, along with a bunch of extra leaves for the larvae to use if needed, and waited to see what would happen.
A week later, I was surprised to see a little beetle appear in the vial, and I was even more surprised when close inspection revealed that the beetle was a fly!
It had emerged from the puparium, which in lateral view I could now see was dorsoventrally compressed at the anterior end, unlike the symmetrically capsule-shaped puparium of an anthomyiid fly.
This puparium shape is typical for the superfamily Ephydroidea, which includes Drosophilidae (fruit/vinegar flies) and Ephydridae (shore flies). Both of these families include leafminers, and shore flies glue their white eggs to the surfaces of leaves in the same way that Pegomya species do. Most leaf-mining shore flies are in the genus Hydrellia and feed on freshwater aquatic monocots. Besides the duckweed specialist Lemnaphila scotlandae, I was aware of one other: Psilopa leucostoma, which is an introduced European species associated with Amaranthaceae (Atriplex, Beta, Chenopodium). My weirdo fly turns out to be the only North American representative of a related genus: Clanoneurum americanum. The wings of the one I reared are properly developed for the species. In the process of figuring this out, I came across a paper that had documented the life history of this fly forty years earlier:
Wheeler, A. G. 1982. Clanoneurum americanum (Diptera: Ephydridae), a leafminer of the littoral chenopod Suaeda linearis. Proceedings of the Entomological Society of Washington 84(2): 297–300.
You can read the paper for free here, thanks to the Biodiversity Heritage Library, which, thanks to the current assault on all that is good in the US government, is now looking for help because it is losing the support of the Smithsonian Institution.
Behold! This little fly emerged the day before yesterday.
It might look like a pretty generic fly (it happens to be an agromyzid in the genus Agromyza), but take a look at the lid of the vial in which it appeared:
My already indecipherable writing has been made worse by its being partially faded or rubbed off over time, but what it says is “6/6/23 / Long Mtn / fuzzy brome / B. pubescens / 5 lvs, all out by 6/12-13 / Full depth.” Which is to say: the vial contained puparia from five mined leaves of a fuzzy-leaved brome (grass) that I collected at Long Mountain (in Belchertown, Massachusetts) and determined to be Bromus pubescens (common name = “hairy woodland brome”); the mines were full-depth, meaning they were equally visible on both sides of the leaf, and all of the larvae exited the leaves and formed their puparia by June 12 or 13—not 2024, but 2023! I’m not aware of any recorded instances of agromyzids having a two-year pupal diapause, but the puparia still looked to be in good shape last fall when I was discarding rearing projects that were no longer worth keeping, so I decided to keep them for another winter. And this one is a male, so it will be identifiable to species, once Owen Lonsdale has a look at its genitalia. My decision not to give up on these puparia just yet was influenced by the fact that there are no records of any Agromyza species being reared from any Bromus species in North America.
Here’s a photo I took of one of the mined leaves as I was collecting them. As far as I can tell, the mines of all the grass-feeding Agromyza species look exactly like this, although some are visible only on one leaf surface, which is why I made the note about these being full-depth.
And for those who are curious, here is what the inside of the rearing vial looks like after almost two years. Plenty of black mold growth on the crumpled-up piece of toilet paper I stuffed into the bottom with a few drops of water added periodically to maintain a somewhat humid environment, but most of the puparia themselves are still not moldy, which is what gave me hope that they might still be viable.
Relatedly, on March 18 I was excited to discover that two sawflies had emerged in one of my peanut butter jars with soil in the bottom. I looked at the lid and saw that some inchworms had burrowed into the soil last spring. Were these actually ichneumonid parasitoids that I had mistaken for sawflies? I took a closer look:
Nope, definitely sawflies! Specifically, a female and male of Nematus abbotii (Tenthredinidae). I looked at the older writing on the lid and saw that on June 11, 2023, I had collected some sawfly larvae from bristly locust (Fabaceae: Robinia hispida), and five of them had burrowed into this soil by June 14. A male and female of N. abbotii had already emerged in this jar on April 3 and 9, 2024, so when I needed soil for those inchworms two months later and no more sawflies had emerged, I figured I could just recycle that soil—but I didn’t cross out the older writing in case something like this happened. (I should also point out that when I recycle soil like this, I make sure not to reuse sawfly soil for sawflies, or gall midge soil for gall midges, etc.) Here’s what one of the larvae looked like:
Nematus abbotii has not been reared before, but in a paper published in 2008*, Dave Smith reported that shortly after catching many adults of this species in a trap that was set among black locust (Robinia pseudoacacia), he noted “a number of edge-feeding, dark-spotted larvae on the leaves of the trees which were undoubtedly those of N. abbotii.” Sadly, Dave, on whom I always depended for sawfly identifications, passed away between the time I collected these larvae and the emergence of the first adults. A curious thing is that 40 years ago, Dave and Chris Darling published a paper describing a new species, Nematus hispidae (now Euura hispidae), which Chris had reared from very similar larvae on bristly locust at the Cornell University campus in Ithaca, New York**. Larvae of both species are initially solid black, as seen here in a photo taken as I was collecting the N. abbotii larvae:
And evidently the species of locust on which they are found cannot be used to distinguish them, as might have been assumed previously. One difference that seems to be consistent is that whereas E. hispidae inserts its eggs in the leaflet midribs, N. abbotii inserts them in the rachis of the compound leaf—as was first documented by Yurika Alexander on BugGuide, and I found similar oviposition scars in association with the larvae I collected.
Dave told me in 2022 that he was unaware of any specimens of E. hispidae beyond the type series, whereas N. abbotii has been collected all over eastern North America, from Ontario to Georgia, west to Kansas. So it would not be unreasonable to assume that larvae like this are N. abbotii, unless you happen to be in Ithaca, New York…
Sawflies sometimes having a larval diapause of two or more years is a well-known phenomenon, but I have only experienced it firsthand once or twice before. Gall wasps (Cynipidae) have been reported to emerge from galls collected several years earlier, and I believe I remember reading that gall midges (Cecidomyiidae) can emerge as adults as many as twelve years after burrowing into soil as larvae.
I’d like to close this post with a little PSA for BugTracks subscribers. At some point, WordPress switched from sending subscribers an email with the first few lines of a new blog post followed by a link, to sending emails that have the entire blog post embedded, complete with illustrations. This has led many people to forget, I think, that my blog is a thing that exists out there on a website, and is not just something you are getting in an email from me. When you respond to one of these blog emails, you are not writing a private message to my email account; you are leaving a comment that will be posted publicly at the bottom of my blog post. I moderate comments before they appear, so I haven’t been approving comments that are clearly not intended for public consumption, but it is not always clear to me what the intent is. Also note that in many cases these comments appear anonymously, so I don’t know who to respond to if you write with a question. For instance, someone wrote in response to my last post, “I didn’t get any photos with the email. Maybe it’s my end??” The answer to that is yes, the problem is at your end, and the solution is to click the title at the very top of the post so you can read the blog on my website! I would really suggest that everyone do this, because I very often add some edits or updates after publishing a blog post, and these changes will not be reflected in the emailed version.
* Smith, David R. 2008. The abbotii and erythrogaster groups of Nematus Panzer (Hymenoptera: Tenthredinidae) in North America. Proceedings of the Entomological Society of Washington 110(3): 647–667.
** Darling, D. Christopher and David R. Smith. 1985. Description and life history of a new species of Nematus (Hymenoptera: Tenthredinidae) on Robinia hispida (Fabaceae) in New York. Proceedings of the Entomological Society of Washington 87(1): 225–230.
On October 6 last fall I visited Aton Forest in northwestern Connecticut, in part to look for some leafminers I had found there the previous year on red oak (Fagaceae: Quercus rubra). I found what I was looking for (mines of a few different moths in the families Gracillariidae, Nepticulidae, and Tischeriidae), and I collected a number of leaves with the hope of rearing some adults. Eight days later, I noticed this larva resting on one of the leaves:
I recognized it as belonging to the genus Bucculatrix (Bucculatricidae), species of which are commonly known as “ribbed cocoon maker moths.” The oak-feeding species in this genus are leafminers very briefly, then exit to feed externally in little patches on the lower leaf surface. I scanned the leaf and was able to locate the tiny mine that this larva made in early life. In the backlit photo below, the mine is the largely frass-filled patch to the left, and the white patches to the right are some of the later “window-feeding” (the upper epidermis is intact, but not visible in the photo because the feeding sites are a bit overexposed).
When I discovered this larva, it was full-grown and was just sitting there, not feeding. So I suspected that it was getting ready to spin its fancy ribbed cocoon. Sure enough, when I checked on it exactly two hours later, it was busily spinning away. I took all of the photos below in the space of a minute, and then I went to bed.
When I was writing Tracks & Sign of Insects…, I came across a detailed description of how a Bucculatrix larva goes about making its cocoon. I think it was written early in the 20th century or so, but I don’t now remember where I found it. Clearly, though, at some point the larva has to switch from working on the outside to lying on its back and spinning from the inside. I think it must leave a little gap near one end of the cocoon, crawling through this opening when the exterior is finished, and then filling the gap in, as well as thickening the entire wall of the cocoon.
When I checked in the morning, exactly 12 hours later, the cocoon was finished:
Note that toward the right side of the upper photo, and toward the left side of the lower photo (in which the cocoon is rotated 180 degrees), there is a point where the longitudinal ribs are a bit broken; I’m assuming this is where the larva had left a gap to crawl through. Not long after the cocoon was finished, I put it in the fridge for the winter, and I took it back out three weeks ago. Yesterday, the adult emerged, leaving its pupal skin protruding from the cocoon:
Unlike most Bucculatrix adults, this one was easy to identify, based on its having a white ground color with a lot of dark speckling and a large, dark, dorsal oval: Bucculatrix ainsliella. This is probably the most common oak-feeding Bucculatrix in northeastern North America, and it also showed up in Europe about 20 years ago. We have about 100 described Bucculatrix species in North America, and plenty left to name. I’ll try to get to those sooner or later…
This may not be the most exciting read, but it will give you a little window into the sorts of problems I’m wrestling with while trying to attach names to the insects I’m studying, as my country crumbles around me. I was asked a seemingly simple question by Steve Nanz this morning, and the more I thought about it, the more it made my head hurt. Instead of writing an extremely long response in a BugGuide comment, I thought it would be useful to lay some things out in a blog post. Might as well start from the beginning…
Gracilaria quinquistrigella (Gracillariidae) was described by Kentucky lepidopterist V. T. Chambers in 1875 from a specimen caught in Texas (he misspelled the genus, which should have been Gracillaria). Its host plant was unknown. Very little has been published about this species since. Forbes (1923) included it in Lepidoptera of New York and Neighboring States, under the name Acrocercops quinquestrigella (misspelled), and quinquistrigella was still listed in that genus by Don Davis in the Hodges et al. (1983) Checklist of North American Lepidoptera. Forbes indicated that Coriscium rhombiferellum, which was described in 1876 by the German lepidopterists Frey & Boll from another specimen caught in Texas, was a synonym (based on what evidence, I don’t know), but Don listed rhombiferellum as a valid species (not having seen the type specimen, as far as I know). Based on my quick reading of the original description of rhombiferellum (in German), it doesn’t sound like the same moth, but it would be nice to see it to make sure. Frey & Boll’s specimens are mostly at the Natural History Museum in London, and today I wrote to the curator who in the past has provided me with images of such things, but I got an auto-reply saying that he is on leave. Anyway, Forbes stated that Acrocercops quinquestrigella occurs in Kentucky and Texas—neither of which are “neighboring states” of New York, last I checked—and I think this must have been an error based on the fact that Chambers lived in Kentucky. Charles Kimball’s 1965 Lepidoptera of Florida includes Acrocercops quinquestrigella based on three specimens reared from Sida rhombifolia (Malvaceae) by Carl Stegmaier (who later published a series of papers about Florida’s leaf-mining agromyzid flies), dated March 7, 1963. Charles Covell, in his 1999 checklist of the butterflies and moths of Kentucky, included A. quinquistrigella based on Forbes’ error. And that’s it.
In November 2012, Julia and I collected some leaf mines on narrow-leaved globemallow (Malvaceae: Sphaeralcea angustifolia) in Texas.
When finished feeding, the larvae exited their mines and spun cocoons. One did so at the bottom of a rearing vial, so I was able to get a look at the larva inside its cocoon through the side of the vial:
Here’s the finished cocoon viewed from above, now containing the pupa. Note the “frothy bubbles” on the surface of the cocoon at either end, which are characteristic of certain gracillariid moths.
I ended up getting only parasitoid wasps from the larvae we collected, but we also collected one cocoon along with the mines, and an adult emerged from it. Here’s the cocoon with the empty pupal skin poking out of it…
…and the adult:
I tentatively identified this as Acrocercops quinquistrigella based on Kimball’s record from Florida; at the time it was the only published record of a gracillariid reared from a mallow in North America, and the description of the adult was a good match.
Five years later, Mike Palmer collected leaf mines in Oklahoma from an unrelated plant called betonyleaf noseburn (Euphorbiaceae: Tragia betonicifolia). The only leafminer known from Tragia was Cyphacma tragiae, a weird moth that Annette Braun described in 1942, which currently is not assigned to a family or even a superfamily. Here is one of the adults that emerged from Mike’s mines:
Braun had mentioned that sometimes the cocoon of C. tragiae is decorated with a few frothy bubbles, which would be a really weird coincidence since these bubbles are otherwise unique to Gracillariidae (and C. tragiae definitely isn’t a gracillariid). I suspect that Braun observed some cocoons of this species that Mike found, didn’t have adults emerge from them, and assumed that they were made by the same species she reared from plain cocoons. But what was Mike’s moth? On October 15, 2017, I wrote to Don Davis:
I’m curious for your thoughts on the moths in the two [above] photos. The first was reared from Sphaeralcea angustifolia in Texas a few years ago; I had thought it might be Acrocercops quinquistrigella, since this species reportedly has been reared from Sida rhombifolia (both Malvaceae). The second emerged just yesterday from Tragia betonicifolia (Euphorbiaceae) in Oklahoma. They look to me to be the same species, despite such distantly related hostplants. I’m wondering what the status of A. quinquistrigella is, given that it was described from a caught specimen that may or may not still exist. If these moths are that species, it seems that it may really belong to another genus?
Don replied:
Thanks Charley for the photos and interesting notes. Your photos closely resemble the few Acrocercops quinquistrigella in [the Smithsonian] collection (including the type) but the male genitalia should be compared. Unfortunately the few specimens that I have are mostly missing abdomens (including the type) and I have only been able to draw the female genitalia. One specimen that we have was reared from Sphaeralcea in Texas [in 1939]. . . Please collect all you can for future comparisons.
Don sent this photo of what he said was the type specimen:
On July 5, 2019, Don wrote:
Hi Charley:
Would you be interested in contributing as a co author to 2-3 MONA [Moths of North America] volumes on the North American Gracillariidae? I have completed most of the illustrations (see attached list) and have already published on some species (a few with you). Dave Wagner has asked to be included as the third author on this project. It would be good to have someone primarily responsible for the descriptions of the adults, which perhaps you and Dave could do. I would be able to describe most of the genitalic morphology, and hopefully complete any remaining illustrations. We should also include distributional maps for the species.
The first volume would treat the subfamily Gracillariinae. A few years ago I began portions of the first volume (see attached) and this needs to be updated and completed.
I still have a few other projects to complete, but hope to start working on the Gracillariinae more next year, if I can receive some help.
Please let me know if you are interested in this project.
Best wishes,
Don
I knew from previous correspondence with Don that he was aware of over 100 undescribed species in addition to the 300+ already named species of Gracillariidae in North America (which he had been studying since the 1960s, even if he said he hadn’t begun work on this monograph until “a few years ago.”). I also knew from previous discussions with Dave that Dave’s contribution would be limited to the extensive rearing that he had already done, beginning in the early 1980s; he was (and is) too busy with other things to have any time for describing or writing about Gracillariidae. So I was aware that this would be no small undertaking, but I eagerly agreed.
I began by comparing Don’s species list against the one I had made for Leafminers of North America, which followed the recent reorganization of Gracillariidae into eight subfamilies (previously there were just three, and most of the new ones were split out from what Don was referring to as Gracillariinae). Earlier that year, Greg Pohl had enlisted me to take the lead on the Gracillariidae section of the new Annotated Taxonomic Checklist of the Lepidoptera of North America, north of Mexico, so going over Don’s list complemented that effort well, and of course I invited him to be a coauthor.
When I came to the Acrocercops section, I found that almost nothing in that genus actually belonged there. Don had determined that three species belonged in the genus Cryptolectica, which hadn’t been documented as occurring in North America previously. We also transferred A. cordiella, a Cuban species that Don had found in Texas, to Dialectica and added it to the list. Three other species, A. arbutella, A. astericola, and A. pnosmodiella, are misplaced in Acrocercops but Don hadn’t determined the correct placement, so we left them there with the “Acrocercops” in quotes. In the file Don sent me, he had a note by quinquistrigella: “n. gen. [new genus] in Lithocolletinae?” Operating under the assumption that the globemallow leafminer was in fact quinquistrigella, it was clear to me from the larval biology that this species does not belong in Acrocercopinae, since one of the defining characters of that subfamily is that the larvae turn bright red when mature. Lithocolletinae also wasn’t a good fit, and the general appearance of the leaf mine and adult (as well as the frothy bubbles on the cocoon) fit well with Ornixolinae, so we moved it there. It obviously didn’t make sense to keep it in Acrocercops, and we also couldn’t revert it to the genus Gracillaria, since that is in the subfamily Gracillariinae, so we just listed it under “unknown genus.” This left just A. rhombiferellum (discussed above) and the oak leafminer A. albinatella under Acrocercops, without quotation marks—and whether A. rhombiferellum really belongs there needs further investigation.
And then Don had listed under “NEW GENERA – Gracillariinae” the species albomarginatum, described by Walsingham in 1897 from Saint Thomas in the Virgin Islands. Next to this name, Don had the note, “Devil’s Den, AK, 16744 TL = St. Thomas” (TL meaning type locality). Devil’s Den is in Arkansas (AR), not Alaska (AK). Walsingham had described the species in the genus Coriscium; somewhere along the line it had been transferred to Acrocercops, but Don had determined that it belonged to an undescribed genus.
Beyond putting together the updated checklist, work on the Gracillariidae monograph stalled, because Don wanted to finish his monograph on fairy moths (Adelidae) before turning his attention to this family, and then COVID-19 happened and Don was shut out of the museum for over a year—and he had no computer at home, so I don’t think he was getting much done there, if anything, and there was no easy way to communicate with him. In May 2020, I added a note in Don’s file next to albomarginatum, “looks a lot like quinquistrigella (Ornixolinae)”—but I have no recollection of ever discussing that with Don, and in the final checklist (published in 2023) it is listed with the other three species under “Acrocercops” in quotes, with the note that it “is included in this list based on specimens in the USNM [United States National Museum] collected at Devil’s Den, AR.”
Don’s fairy moth monograph was finally published in 2023, just in time for all the new species he described in it to be included in the new checklist. Meanwhile, he informed me that now he had two other projects that he wanted to finish before turning his attention back to Gracillariidae. He was still working on the first of these when he passed away in October 2024. A huge loss, to say the least.
In the past few weeks, after a long hiatus, I’ve returned to dissecting tiny moths and trying to learn to make slides of their tiny tiny genitalia that are presentable enough to be published, so that I can start describing new species on my own. It’s going pretty well, except for some frustrations like brownish blobs surrounding the genitalia (caused by incomplete mixing of the clove oil that I’m supposed to leave the genitalia in for a few hours before putting them in Canada balsam on the slide), and the difficulty of removing a zillion specks of dust from the coverslip, which are invisible until viewed under the compound scope (the example below is from a male of Parornix betulae):
At this point I’m not sure if it would be more time-consuming to try to use a photo editing program to get rid of all the imperfections in my images, or actually do the tedious things that knowledgeable people are telling me I need to do to fix these issues.
Anyway, this morning Steve Nanz commented on this photo of a moth in Oklahoma that I had identified as “Acrocerops” quinquistrigella in 2017, noting that this moth’s DNA barcode had matched it to a specimen that Don Davis had identified as “Acrocercops” albomarginatum. He asked for my feedback on his treatment of this species on BugGuide and the Moth Photographers Group website. I had forgotten all about this species, but after looking into it, I have these comments and questions:
There are photos of the type specimen and its (male) genitalia here. That’s very helpful.
In his “1933” (actually published in 1934) paper on the Microlepidoptera of Cuba, August Busck wrote of this species (under the name Neurobathra albomarginata): “Described from St. Thomas and recorded from Porto Rico by Forbes, but foodplant hitherto not ascertained. Mr. Otero reared the species repeatedly from leaf-mining larvae of Bradburya plumieri. (Otero No. 9679.)”. That plant is now known as Centrosema plumieri (Fabaceae). Did Busck dissect one of these reared specimens to confirm that it was the same species?
There are several species of Centrosema in the US (some of them known as “butterfly peas”), but to my knowledge no one has found leaf mines on them that could possibly have been made by this moth. Presumably Don compared the genitalia of a male from the US with the type specimen to make his determination. But the two specimens he identified as albomarginata that have DNA barcodes (here and here) were collected by Don and his wife in 1984 in Oklahoma (well away from the Arkansas border), not in Arkansas. Why didn’t he mention these, or are these in fact the specimens that he said were collected in Arkansas? And what evidence is there that this species isn’t synonymous with quinquistrigella, if the type specimen of that species is missing its abdomen?
There is one specimen identified as quinquistrigella in the Barcode of Life Database, here. It looks just like albomarginata, except the scale bar indicates it is much smaller, with wings only 2 mm long. I am certain that scale bar is incorrect, and I’m not sure I trust any of those scale bars. That specimen was collected in Texas in 1939, and although the label data on the BOLD website don’t say as much, I think it must be the 1939 specimen that Don said had been reared from Sphaeralcea. Troublingly, it is clearly also the same specimen that Don told me was the type. This, I suppose, explains why it is in such good condition; I have seen a lot of Chambers’ type specimens at Harvard’s Museum of Comparative Zoology, and they tend to be in pretty sorry shape. Here, for instance, is the type of Phyllocnistis populiella, the species that makes those beautiful serpentine squiggles on poplar leaves:
One way to move forward would be to compare genitalia and/or DNA from specimens reared from Fabaceae (Centrosema), Euphorbiaceae (Tragia), and Malvaceae (Sida, Sphaeralcea) and see how many species are involved. It would be very unusual for a single gracillariid species to have such disparate host plants. At this point, genitalia-wise, all I have available for comparison is the photo of the (male) type specimen of albomarginatum, which was not reared. I haven’t yet checked what sex my specimens are, but I have the one from Sphaeralcea (Texas) and four from Tragia—two from Mike Palmer in Oklahoma, and two from Chet Burrier in Texas. If there turn out to be multiple species in Texas that look like this, there may be no way to determine which one is quinquistrigella, although getting a look at the actual type specimen would be a good start.
That one alleged quinquistrigella specimen has not been assigned a BIN (Barcode Identification Number), but it does have a partial sequence, so we can visually check to see how well it matches the Oklahoma albomarginatum specimens. Here’s the “quinquistrigella” (the Ns are the missing bits):
I copied and pasted these into a Word document just now, colored the “quinquistrigella” in red, and shuffled the two together so we can compare them line by line. Ignoring the “N”s, they appear to be identical except for one T-C substitution, which I’ve highlighted in yellow below (and I’ve put this in boldface in the two sequences above, but it’s a little subtle):
Not a big enough difference to say these are two different species, for sure. If both August Busck and Don Davis made their identifications of albomarginatum based on comparison of the genitalia with the type specimen of that species (and this may be possible to determine, eventually*), then this suggests that the mallow feeder could in fact be the same as the legume feeder. (There is some precedent for this; the leaf-mining fly Calycomyza malvae feeds on both mallows and legumes.) It doesn’t tell us anything about the true identity of quinquistrigella, but it’s a start. If the Tragia feeder turns out to be the same as the mallow feeder, there will be a strong case for synonymizing albomarginatum with quinquistrigella.
So, to answer your question, Steve, I don’t know. I guess it’s fine for now, except I’ve moved albomarginatum to Ornixolinae on BugGuide, so that it’s grouped with quinquistrigella under “genus undetermined.”
* Added the next morning: As I was closing the numerous tabs I had opened on my browser while writing this post, I noticed that this specimen shown on BOLD (from which no DNA sequence was obtained) has the following note: “E.E.A. de Cuba No. 9679|Pupated: Dec.21.1931|Genitalia on slide AB Mar/6/1937; leaf miner on Bradburya plumieri.” So August Busck did dissect at least one of those reared specimens from Cuba, and the genitalia slide is at the Smithsonian, so surely Don would have seen it (although this one is a female). It’s still a mystery why Don was identifying some specimens as albomarginatum and others as quinquistrigella, and whether the alleged quinquistrigella female he illustrated showed any differences with albomarginatum.
Another thing I thought to check just now is that the Barcode Identification Number for albomarginatum (BOLD:ABX0021) has its nearest neighbor at a distance of 10%, and that is the South American species Acrocercops serrigera, which feeds on mallows**. That BIN, in turn, has its nearest neighbor at a distance of 8%—an undetermined gracillariid that has been collected in Florida, Mexico, and Costa Rica. Both of these moths look very much like albomarginatum and quinquistrigella, except they appear to lack the dark speckles in the white dorsal margin.
…And another update! (February 16, 2025): This morning I started organizing my copies of Don Davis’s genitalia drawings in a way that will make things easier to find, and I discovered that I do in fact have his drawings of male and female albomarginatum genitalia. In the male drawing, there are a number of differences with the type specimen that seem rather significant to me. Unfortunately his drawings don’t generally indicate what specimens they are based on, but there are some drawings that are annotated with “holotype” or “paratype,” and this isn’t one of them. It therefore seems likely that these are based on the specimens from Oklahoma (or Arkansas, if such specimens exist). I suppose they could also be based on Busck’s slides, but in any case they represent Don’s concept of albomarginatum. Pending further investigation, I am inclined to think the North American record of albomarginatum is based on a misidentification. Supporting evidence includes the facts that BIN BOLD:ABX0021 only has specimens from Oklahoma and Texas (none from the Caribbean), and that no one has yet found mines on Centrosema in North America that could have been made by anything related to these moths (but this is only relevant if Busck’s identification of the reared Cuban specimens was correct).
Once I’ve got my slide-mounting issues worked out, I can dissect my specimens from Sphaeralcea and Tragia and see how they compare with one another, and with Don’s drawings, and with the type of albomarginatum. And hopefully I can get DNA barcodes from them at some point. Then there’s the matter of comparing these moths against the 28 described genera of Ornixolinae to see if any of them fit, before contemplating describing a new one.
** Bernard Landry’s 2006 paper describing the subspecies Acrocercops serrigera galapagosensis states that the larvae feed on flower buds of Waltheria ovata, rather than being leafminers. The genitalia in his figure are more similar to the type of albomarginatum than is what Don Davis illustrated for albomarginatum. The next species described in Landry’s paper, incidentally, is Caloptilia dondavisi.
On June 9, I was exploring a powerline corridor in Kent, New York when I spotted some little jewels that I recognized as the poop-covered eggs of a leaf beetle in the tribe Clytrini (Chrysomelidae: Crytocephalinae). They were the first I had seen since July 2008, when I photographed the ones in Arizona that are shown on page 165 of Tracks & Sign of Insects and Other Invertebrates. I am now much better set up for macro photography than I was when I wrote that book, but lately I have taken to only bringing my phone with me to take photos while conducting fieldwork, instead of stumbling around with two DSLRs dangling from my neck, so I collected one of the egg clusters to photograph later.
I figured I might as well hang onto them to see if they hatched, and on June 21 I was treated to the sight of tiny beetle larvae hauling around their egg coverings as portable houses.
Some case-bearing leaf beetles (Cryptocephalinae) feed on living leaves, in which case the identity of the plant their eggs are found on may be significant, but as I wrote of the Clytrini on page 254, larvae of at least some species feed on debris in ant nests. The egg cluster I collected was on some kind of grass, but I saw a few others on other plants in the same area, so I assumed these were a debris-feeding species. I put some miscellaneous living and dead plant material and soil/duff in the vial with them, but I did not succeed in rearing them further. For what it’s worth, here are the two species of Clytrini I’ve met as adults:
Anomoea laticlavia (this one was in Minnesota, and I found another one in Massachusetts)…
The vast majority of leafminers are highly host-specific, feeding in leaves of a single plant genus or a few closely related genera. For this reason, it has always bothered me that the weevil Orchestes mixtus (Curculionidae) mines leaves of every genus in the birch family (Betulaceae: Alnus, Betula, Carpinus, Corylus, Ostrya; otherwise known as alder, birch, musclewood, hazelnut, and hophornbeam), plus elm (Ulmaceae: Ulmus), which is not only in a different family but even a different order (Rosales instead of Fagales).
Meanwhile, another species that is basically identical except for its genitalia, Orchestes pallicornis, feeds on a bunch of different genera in the rose family (Rosaceae: Amelanchier, Aronia, Crataegus, Cydonia, Malus, Mespilus, Prunus, Sorbus; otherwise known as shadbush, chokeberry, hawthorn, quince, apple, medlar, cherry/plum/peach, and mountain-ash), which belongs to the same order as elm.
Wouldn’t it make more sense for the species on elm to be O. pallicornis, or maybe a third species? As I noted in a paper about assorted weevils a couple of years ago*, O. mixtus is abundant on plants in the birch family in New England, but conspicuously absent on elms here. All the records of it feeding on elm are from farther south and/or west: Ontario, Virginia, West Virginia, Oklahoma, Arkansas, and Texas. Highly suspicious.
In the spring of 2023, Tracy Feldman found O. mixtus mining a leaf of winged elm (Ulmusalata) in North Carolina. I seized on the opportunity to do a little DNA comparison; I collected some Orchestes mines on black birch (Betula lenta) and pin cherry (Prunus pensylvanica) and reared adults of O. mixtus and O. pallicornis from them, respectively. I sent them off to Matt Bertone, along with Tracy’s adult reared from elm, and Matt and his colleague Swarnalatha Moparthi performed the magic technique known as “DNA barcoding,” which somehow takes a tiny chunk of tissue from an organism and translates it into a long string of C’s and G’s and T’s and A’s on a computer. This string of letters (the “barcode”) is comparable from one sample to the next because it begins at the same point on the same gene. The barcode is just a little snippet of one gene, and not the whole genome, which would be ideal for reaching a definite conclusion but is much more expensive to obtain. In general, it is assumed that two barcodes that differ by less than one percent represent the same species, and those that differ by more than a few percent represent different species; in between is a bit of a gray area. Humans and chimpanzees differ by 1.2% (I believe that’s based on the whole genome).
As reported in our short paper that was published this spring**, the barcode of the specimen from elm (whose barcode can be seen here) did not differ notably from the barcode of the birch specimen; they both correspond with the barcode identification number (BIN) BOLD:AAM7599. Specimens with the same BIN are assumed to represent the same species in the absence of evidence to the contrary. In this case, no differences have been found in the adult weevils (including genitalia), so the only evidence to the contrary is the limited geographic distribution of elm-feeding O. mixtus.
The specimen from pin cherry, on the other hand, differed by 8.7–10.7% from other specimens of O. pallicornis! So we seem to have found a cryptic species we weren’t looking for. None of us being weevil taxonomists, we’ve left it to others to decide what to do about that. Checking our barcode against the whole Barcode of Life Database (BOLD) just now, I find that the most similar barcode (which is also from a specimen identified as O. pallicornis) is a bit closer than the range we reported, differing by 7.95%, but this is still a huge difference for something that is supposed to be the same species. Foreshadowing this result (in hindsight), in my 2022 weevil paper I noted that three O. pallicornis adults I reared from black cherry (Prunus serotina) showed no interest in a shadbush (Amelanchier) leaf I offered them, but immediately began to feed on a black cherry leaf that I later added to the rearing vial.
Several years ago, Björn Rulik (who was a coauthor on both of my papers describing new species of leaf-mining dark-winged fungus gnats) was kind enough to barcode 100 or so specimens I sent him belonging to another group of leaf-mining beetles, the hispines (Chrysomelidae: Cassidinae: Chalepini). The results were reported in a paper that was published a few days ago***. The main focus of this paper was presenting new natural history information (and reviewing what was previously known) about a bunch of different species, but the barcoding results echoed what I just described for the weevil barcoding paper, so I’ll highlight those here.
I had three species that I wondered about being complexes of cryptic species based on what I knew of the hosts and habits of the larvae. The first species, shown in figures 128 and 129 below, is Baliosus nervosus, which has the common name “basswood leafminer,” but in addition to basswood (Malvaceae: Tilia americana), it feeds on elms, plus members of the birch and rose families, plus members of the beech family (Fagaceae: Castanea, Quercus; = chestnut and oak). A single beetle species, or one or more host-specific species that look similar?
It turned out that specimens reared from apple, alder, chestnut, oak, and basswood all had the same DNA barcode, but then there were some specimens from basswood (including the one in Figure 129) that differed from everything else by more than 10%! Evidently another cryptic species, but again not exactly the result I was looking for.
My next target species was Sumitrosis inaequalis, which feeds on many different genera in the aster family (Asteraceae). I had noticed that its mines on asters in the genus Symphyotrichum virtually always look like the one on the left below—long and narrow, with frass deposited along the sides—whereas mines on every other host genus virtually always look like the one on the right: a compact blotch with crisscrossing frass threads deposited throughout, except at the edges. Do these two patterns represent two different beetle species?
Nope, the barcodes from these two different types were all jumbled together. Sumitrosis inaequalis is the beetle in Figure 151 below.
The third species I wanted to investigate is another Sumitrosis, S. rosea. This species mines leaves of a variety of legumes (Fabaceae), plus wood nettle (Urticaceae: Laportea) and bittersweet (Celastraceae: Celastrus). I’m not the only one to suggest that these disparate hosts may correspond with different beetle species. Figure 153 above is a typical (pale brown) legume-associated adult, and the black one in Fig. 156 was reared from bittersweet. Surely these are two different species, right? Well, if so, they’re not as easy to distinguish as you might think, because Figures 154 and 155 show two adults that are probably siblings; they were reared from the same collection of wood nettle leaves. And once again, the barcodes of adults reared from these three different host families were all mixed up together, so these seem to all represent a single variable species with peculiar tastes.
But then, in our random barcoding of other hispines, which was just done to get a sense of the typical variation in barcodes within and between species, we turned up one Sumitrosis result that seems to represent the sort of thing I was looking for. Sumitrosis ancoroides is known to feed on two different legume genera, Strophostyles and Stylosanthes. The specimens that Tracy Feldman reared from Stylosanthes biflora (pencil flower) in North Carolina (Figure 149) differed by 10.72% from the ones that Mike Palmer reared from Strophostyles helvola (trailing fuzzybean) in Oklahoma (Figure 150). There do seem to be some differences between these two adult beetles; I’m hoping someone else will investigate this and figure out if these are consistent differences that can be used to describe a new species. Differing barcodes also suggest that some other species, such as Microrhopala excavata and Odontota horni, warrant a closer look, although I must say I’m less excited about cryptic species that don’t seem to correspond with any obvious differences in host plants or larval biology.
* Eiseman, Charles S. 2022. New rearing records and observations of weevils with folivorous larvae (Coleoptera: Curculionidae). Proceedings of the Entomological Society of Washington 123(4): 727–740.
** Eiseman, Charles S., Tracy S. Feldman, Swarnalatha Moparthi, and Matthew A. Bertone. 2024. Investigation of possible cryptic species within Orchestes mixtus Blatchley and O. pallicornis Say (Coleoptera: Curculionidae: Curculioninae: Rhamphini) using DNA barcoding. Proceedings of the Entomological Society of Washington 126(2): 243–246.
*** Eiseman, Charles S., Tracy S. Feldman, and Michael W. Palmer. 2024. New larval host records, parasitoid records, and DNA barcoding data for North American leaf-mining leaf beetles (Coleoptera: Chrysomeloidea). Zootaxa 5549(1): 1–60.
Things have been pretty quiet around here on the BugTracks blog lately, but I think that’s going to change pretty soon. As usual, I was busy with fieldwork from May to October, and for the past few weeks I’ve been busy writing, revising, and reviewing a bunch of papers (as well as putting together the monthly installment of the third edition of Leafminers of North America), but any day now I’m going to start going through all my photos from this year, and when I come across anything particularly interesting, I’ll write about it here.
In the meantime, as with every year in recent memory, I’ve just put together a wall calendar as a thank-you gift for my most generous patrons, and I will also send a copy to anyone who makes a donation of at least $30 (the amount WordPress charges me each year to keep this blog free of annoying ads) before the end of November, which you can do here (select “Send,” and then include your mailing address in the notes). In this year’s calendar, each month features a (more or less seasonally appropriate) leaf mine that is either a total mystery or needs further investigation (e.g., I’ve reared some adult females of the insect responsible for the mine, but males are needed to identify the species, or describe it if it turns out to be new).
And speaking of beetles associated with galls (which we were, briefly, several weeks ago in my previous post), here’s an odd thing I noticed last May while wandering in the woods of Aton Forest in northwestern Connecticut. A lot of the leaves of shagbark hickories (Juglandaceae: Carya ovata) were covered with little round, flattened galls:
Nothing too odd about that; galls like these are a common sight on hickories, and they are caused by aphidlike insects called phylloxerans (Phylloxeridae: Phylloxera spp.). Here’s a larger (7 mm across) gall of a different species that I cut open 14 years ago to get a look at the Phylloxera nymphs within:
The odd thing was that I kept seeing little weevils on the leaves with the galls. I didn’t think much of the first one I saw, but after the second or third weevil, I started to wonder, “What is it with you guys and these galls?” As I wondered this, I had a vague recollection of having seen weevil larvae come out of phylloxera galls at some point. And I wondered if the dark blemishes I kept seeing on these galls had been caused by the weevils I was seeing, maybe chewing holes in which to lay eggs. The one weevil I photographed in the field was certainly doing something to one of the galls:
So naturally, after I ate the sandwich I had brought, I put several gall-laden leaves in my sandwich box along with a few weevils, including a mating pair. At home I got some better photos of the weevils, including this one:
And when trying to get better photos of the galls, it was hard to find any that didn’t have the dark blemishes on them—they were made from the lower surface but the damage was often visible from the upper surface as well.
On May 29, twelve days after I had collected the galls, a couple of squirming, legless weevil larvae appeared in my sandwich box.
The galls, to my surprise, had continued to develop on the detached leaves, and were now nearly spherical in some cases.
Some galls had been visibly munched, presumably by the weevil larvae, although in some cases this may have been from a few caterpillars that had hatched on the collected leaves and were now devouring them.
One of the caterpillars was this little inchworm, which I first noticed on May 19:
By May 27 it looked like this, and was recognizable as the larva of a “half-wing” (Geometridae: Phigalia titea):
There were also a couple of owlet moth caterpillars, which looked like this on May 27:
By May 29 the second one had molted, confirming my suspicion that these were larvae of the “ruby quaker” (Noctuidae: Orthosia rubescens):
Anyway, I moved the weevil larvae to a jar with soil in the bottom for the larvae to burrow into. On June 11, two adult weevils appeared in the jar. One looked much like the ones I’d photographed previously…
…and one was plain black, without the red markings on the elytra.
Knowing what these weevils did for a living, it took only a quick internet search to identify them as Anthonomus suturalis (Curculionidae), which has been a known associate of phylloxera galls since 1866. The account by Gates & Burke (1972)* makes it sound like the munching on the last gall shown above was in fact caused by the caterpillars rather than the weevil larvae: “By the time a larva has completed its development, the tissue of the inner wall of the gall has been consumed. There is no tunneling by the larvae as in cases of some other Anthonomus inquilines; instead, the inner tissue of the galls is rather smoothly gnawed away. The frass resulting from the activities of a larva is packed in one end of the gall.”
It’s just as well that I didn’t discover anything new about these weevils, because evidently no one is willing to review my papers about weevils anymore. I submitted a two-page manuscript on leaf-mining weevils to a journal a full year ago, and another one-page manuscript half a year ago, and I’m still waiting for reviews on both of these. This makes me a bit grumpy since I’ve never taken more than a few weeks to review a manuscript, and I only take that long if the paper is several hundred pages long.
As for my vague recollection of having seen weevil larvae come out of phylloxera galls before, I checked my files, and what I was remembering was actually a single gall on a shagbark hickory catkin that I found on the ground on June 1, 2018, possibly having been nipped off by a squirrel. I didn’t take a picture of the gall until eight days later, when things had started emerging from it; at this point the plant material had all turned brown, but you can still get a general idea of what it looked like:
Two identical weevil larvae emerged from this gall, one on June 5 and one on June 9. They were identical with one another, but looked nothing like the larvae of Anthonomus suturalis pictured above.
Also on June 9, this fly larva appeared in the jar with the gall, apparently having emerged from it along with the weevil larvae. I assume it is one of the hover flies (Syrphidae) that are predators of aphids and other insects.
I put these three larvae, along with the gall, in a jar of soil with the hope of rearing adults, but all that ever emerged—in March of the following year—was this blastobasid moth, which Aaron Hunt identified as Asaphocrita busckiella (which he believes to be a species complex):
I’m not sure if anything is known about the larvae of A. busckiella, but I see that A. aphidiella was reported in 1886 to have been “reared from the larvae feeding on the contents of Phylloxera hickory galls.” Blastobasids are known as “scavenger moths”, and I presume the larva was feeding on the damaged plant tissue and maybe on the weevil larvae’s frass rather than preying on whatever phylloxerans weren’t eaten by the fly larva. As for what kind of weevil the weevil larvae belonged to, I have no idea!
* Gates, Danny B. and Horace R. Burke. 1972. Review of the gall-inhabiting weevils of the genus Anthonomus, with description and biology of a new species (Coleoptera: Curculionidae). Annals of the Entomological Society of America 65(5): 1215-1224.
Normally I limit my investigations of stem-feeding insects to those that produce some kind of external evidence that catches my eye (a certain wingstem stem being an exception), but last spring , for whatever reason, I decided to have a peek inside a dead stem of tall blue lettuce (Asteraceae: Lactuca biennis) that had been leaning against the side of my house, right by the front door, all winter long. On April 12, I broke off a short chunk from the top of the stem, split it lengthwise, and immediately saw that there were little round cells in the walls of the stem with larvae inside.
I guessed these must be cryptic wasp galls—something I’d first become aware of in 2019 when two adults of Aulacidea harringtoni (Cynipidae) emerged from a two-inch piece of a Lactuca canadensis stem I’d collected the previous July because it had a puparium of a stem-mining agromyzid fly on the surface.
I put the split pieces of the L. biennis stem in a jar, along with a couple of intact pieces from farther down the stem, and put the jar on a shelf in my office to find out if my guess was right.
Between May 9 and June 10, ten of these wasps emerged in the jar:
These are eurytomid wasps (Eurytoma sp.), which are parasitoids of gall insects rather than being gall inducers themselves. When the first ones emerged, I figured this would be a good time to see some wasp pupae, so I split one of the intact stem pieces. The exposed cells still had larvae inside, and there was also a spider living in the stem’s hollow center.
I think this spider is in the genus Euryopis (Theridiidae), which makes distinctive tufted egg sacs—one of which (maybe) is shown in this post. Here’s a closer view of the above wasp larva:
On May 27, this beetle appeared in the jar.
This is Isohydnocera curtipennis (Cleridae), which I had seen a couple of times in June 2020 wandering around on milkweed plants in my yard. Until this one appeared in that jar, I had been completely unaware that these beetles develop in galls of other insects. It turns out this same species has been reared from stem galls of the goldenrod gall moth Gnorimoschema gallaesolidaginis (Gelechiidae), and of Euura salicisnodus (Tenthredinidae), a sawfly that causes galls in willow stems*.
Between May 29 and June 27, 22 gall wasp adults emerged. Louis Nastasi tells me they belong to an undescribed species of Aulacidea.
I did eventually see a gall wasp pupa, on June 10. I think it was from one of the larvae whose cells I had broken open, and was found loose on the bottom of the jar.
Meanwhile, another 24 parasitoid wasps emerged between June 18 and 27. Twenty-two of them were pteromalids; I’m not sure if the ones shown below are two different species or differently colored male and female of the same species. Probably I’ll never know; I’ve never been able to get anyone to identify the pteromalids I’ve reared over the years.
And there were two of these ormyrids (Ormyrus sp.).
I got the feeling that more and more wasps would just keep emerging indefinitely, but I had to leave for a six-week road trip at the beginning of July, so that’s where the story ends. If you want to learn more about these herb gall wasps—and maybe help make some new discoveries—take a look at Louis Nastasi’s post here. (Most of the galls, by the way, are externally obvious, not cryptic like the ones in this lettuce stem.)
[Edit, 3/20/2024: Louis saw this post and he assures me that all of these parasitoid wasps are undescribed, not just the Aulacidea, for which he already has a name picked out, and he thinks the pteromalids may belong to the genus Homoporus.]
* Sabrosky, Curtis W. 1934. Notes on the larva and larval habit of Isohydnocera curtipennis (Newmn.) (Coleoptera, Cleridae). Journal of the Kansas Entomological Society 7(2): 65-68.
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