Looks like a correction is in order! Back on July 20, I found the leaf mines below on a summer grape (Vitaceae: Vitis aestivalis) vine growing in the narrow space between the upper vegetable garden and the arborvitae hedge. I identified them as the work of “Antispila” oinophylla (Heliozelidae), noting that the genus of this moth would likely have changed by the next time you heard from me.
I made that identification based on statements by van Nieukerken et al. (2012) that there is no evident initial linear portion in mines of the species (plural) currently known as Antispila isabella. In transmitted light, it is clear that each of these mines begins with a narrow, dark line along one of the major veins, before suddenly expanding to a blotch that ultimately obscures most of this linear portion.
And yet: by July 26, all three larvae had cut out their pupal cases, revealing themselves to be Antispila in the strict sense.
The prominent central, longitudinal ridge in the pupal case is unique to Antispila, at least in North America.
If I had found these mines already vacated (in which case the pupal cases would have been formed on the ground and I never would have seen them), I still would have recognized them as Antispila “isabella” because of the relatively large, nearly circular holes. I’m using quotes here because both DNA and morphological evidence indicate there are at least two different species going under this name. But that’s a problem for another time. For now, we’ll call leafminer #139 for this year’s yard list Antispila isabella. Here’s an adult that emerged on July 10 from a leaf mine Julia and I collected on August 29 last year at Black Rock Forest in New York—clearly a species with just one generation per year, especially given that I removed the pupal case from winter refrigeration way back in February.
Meanwhile, on July 22, I found two more grape “Antispila” mines, this time on riverbank grape (Vitis riparia) in the “lower nut orchard.”
Although it wasn’t visible to the naked eye, in these photos I can see that the mines likewise began with a short linear portion, but in this case with an even narrower, broken line of frass, rather than being frass-filled as in the mines on summer grape. These larvae likewise began cutting out their pupal cases on July 23, with the second one finishing on the 26th.
The cut-outs are small and narrow, and the surfaces of the pupal cases are perfectly flat:
This tells us that the riverbank grape miners are “Antispila” oinophylla, the species I had originally assumed the summer grape miners to be. As of today, the correct name for this moth is Aspilanta oinophylla, thanks to a paper Erik van Nieukerken and I coauthored. I have never reared this species, which is why I collected the mines I found in my yard, but the adult is externally indistinguishable from the Virginia creeper leafminer
Antispila Aspilanta ampelopsifoliella:
If you see an “Antispila” with that silvery spot near the tip of the wing, it’s really an Aspilanta. (Incidentally, the name Antispila refers to the pattern of opposing spots on the wing, which is common to both genera; “Aspilanta” is just an almost-anagram of Antispila). Unfortunately, there is one Aspilanta species that doesn’t have this spot, so if the spot is missing, distinguishing the two genera requires rubbing off the moth’s scales to examine the wing venation (or dissecting it to examine its genitalia, or analyzing its DNA… though as far as we know, if the moth lacks that spot and has no white tips on its antennae, it is a true Antispila). Fortunately, the difference in the pupal cases is 100% consistent, so if you’re trying to identify a moth you’ve reared, you’ll have no problem getting it to genus.
And so, leafminer #144 for this year’s yard list is Aspilanta oinophylla. Although, in the interest of full disclosure, there is another unnamed grape-feeding Aspilanta that is externally identical to A. oinophylla but with a different DNA barcode. Its genitalia have not yet been examined and the characteristics of its leaf mine are unknown, so I guess I can’t swear that it isn’t the species I have in my yard. So far that one is only known from Connecticut and Florida.
Before I get to the latest additions to the list, there are a few other updates.
I had hoped to rear some adult moths from the three sweetfern leaf shelters of Parornix peregrinaella I collected back on July 7, but instead 11 of these eulophid wasps (probably a Chrysocharis species) emerged from them between July 22 and 26.
On July 11, I had found this solitary sawfly larva on the planted shadbush by my garage…
…and I wasn’t sure if it was a new species for the yard or the same one I had found on the other side of the house a month earlier (sawfly #14):
The July 11 larva kept nibbling away for a couple of weeks, and its head never turned brown to match the otherwise similar larvae I had found before, but it also never grew noticeably; it started to look sickly, and eventually died. I kept it for a bit longer to see if any parasitoids would emerge, and on July 28 this eulophid appeared (I believe it belongs to the subfamily Tetrastichinae):
I couldn’t find any evidence that it had emerged from the sawfly larva, so I took a close look at the leaves in the vial and discovered that it had emerged from the pupa of another eulophid, which was lying in one of the sawfly larva’s previous feeding sites. So evidently its host eulophid did feed as a larva on the sawfly larva, but the sawfly larva kept feeding for a while after the parasitoid larva had left it. The emerging adult hyperparasitoid chewed a hole in the dorsal surface of the primary parasitoid’s pupa.
I’ve found eulophids emerging from braconid cocoons several times, but this is the first time I’ve personally found conclusive evidence of a eulophid parasitizing another chalcidoid.
You may remember the stem miner (#131) I found on Canada goldenrod on July 20. I wrote: “As far as I know no one has ever reported finding a stem mine on goldenrod before. The agromyzid fly Phytoliriomyza arctica is known to mine stems of other Asteraceae genera in Europe, and adults have been caught on goldenrod in Canada. Possibly this is that species, but it could also be some unknown Ophiomyia…” Well, on July 29 I took a close look at that stem and found that the larva had pupated, showing itself to be an Ophiomyia rather than P. arctica.
The adult emerged on August 3—alas, a female, so we’re stuck with “some unknown Ophiomyia” until someone can rear a male from one of these mines.
I haven’t been able to spend much time in my yard lately, for reasons I’ll explain later, but I’ve managed to add a few more leafminers to the list.
Leaf (stem) miner #145: Ophiomyia sp. (Agromyzidae), on wild lettuce (Asteraceae: Lactuca canadensis). On July 28 I found a couple of aborted mines on a plant that popped up along the driveway among the perennials we’ve planted there to make it appear to passersby that we have a “normal” yard. I reared a bunch of males of this species last year, so I’ll be able to put a name on it eventually. This is the “scab”-forming species I mentioned in an earlier post, first noticed by John van der Linden.
Leafminer #146: Agromyza parvicornis (Agromyzidae), on corn (Poaceae: Zea mays). I found the first mine of this species on the same day, starting as a linear track on the upper leaf surface and then switching to the lower surface where it formed an elongate blotch.
On a nearby corn leaf there was a fall webworm sitting on the cocoon of a microgastrine braconid that had emerged from it. I probably should have collected that to rear, but I was feeling a bit overcommitted right then.
On July 31 I found the time for a more thorough survey of the yard’s latest arrivals and turned up three more species.
Leafminer #147: Liriomyza sp. (Agromyzidae), on white snakeroot (Asteraceae: Ageratina altissima). If you were relying on Tracks & Sign of Insects for leaf mine identification, you would conclude that this mine is the work of L. eupatoriella. It turns out there are at least three different Liriomyza species forming linear mines on white snakeroot, and it’s unclear at this point whether their mines can be reliably distinguished. The mines I’ve collected in the woods behind my house did indeed produce adults of L eupatoriella, but this mine I found under one of the young butternut trees in the “nut orchard” could well belong to another species, which may or may not be L. cracentis.
Leafminer #148: Stigmella nigriverticella (Nepticulidae), on the same blackish red oak sapling that has already contributed two other leaf-mining moth species this season. Mines of this species differ from those of other oak-feeding Stigmellas in being filled with frass throughout their length.
Leafminer #149: Stigmella sp. (Nepticulidae), on black birch (Betulaceae: Betula lenta). This is the most common nepticulid on black and yellow birches in my experience, but it doesn’t have a name yet.
Leafminer #150: The mystery agromyzid on apple mint (Lamiaceae: Mentha suaveolens) I mentioned in my previous post. I’ve been keeping an eye on the apple mint and on August 6 there were a bunch of new mines in evidence, some of which clearly had larvae inside.
I’m now convinced they can’t possibly be weird mines of Calycomyza menthae; they don’t match any known North American mint miner. It occurred to me to check the European leafminer website—having already found one previously undocumented immigrant on a mint (oregano) in my yard this summer—and they seem to be a perfect match for Phytomyza tetrasticha: they begin with a compact brown spiral, followed by a convoluted, intestine-like track with conspicuous feeding lines. Here’s a recently completed example:
However, I hesitate to say the apple mint miner is in fact Phytomyza tetrasticha because the three larvae that have emerged so far all formed pale brown puparia, not black like the one shown on the European website. They’re also a bit more elongate. Needless to say, I will keep monitoring the apple mint patch until I’ve secured some adult males of this species to confirm its identity.
One other recent development is that between August 6 and 8, five adults have emerged of sawfly #35, the gregarious Arge larvae I found defoliating the shadbush by the garage on July 11. Three males…
…and two females.
And finally, the latest additions to the list of plants I’ve eaten in the yard this year:
94. Choke cherry (Rosaceae: Prunus virginiana) – fruit
95. Green bean (Fabaceae: Phaseolus vulgaris) – fruit
96. Groundcherry (Solanaceae: Physalis sp.) – fruit
97. Lemon balm (Lamiaceae: Melissa officinalis) – leaves
98. Anise hyssop (Lamiaceae: Agastache foeniculum) – leaves
99. Cucumber (Cucurbitaceae: Cucumis sativus) – fruit
100. Cilantro (Apiaceae: Coriandrum sativum) – leaves
101. Huckleberry (Ericaceae: Gaylussacia baccata) – fruit
102. Bell pepper (Solanaceae: Capsicum annuum) – fruit
103. Corn (Poaceae: Zea mays) – seeds
104. Dill (Apiaceae: Anethum graveolens) – leaves
105. Rutabaga (Brassicaceae: Brassica napus) – roots