Seems like every time I lay out a long litany of the latest leafminers from my yard, one gets left out as I’m scanning through my recent photos. Here’s one more from June 28:
Leafminer #94: Agromyza reptans (Agromyzidae), on stinging nettle (Urticaceae: Urtica dioica). Mines of this fly turn black even as the larva is still feeding, in contrast with the greenish-brown mines of A. pseudoreptans, which are much more common in my yard but haven’t yet made an appearance this year.
Here’s an adult that emerged in the spring of 2018 from a leaf mine I collected the previous October.
On June 27 I found a mine of the weevil Orchestes pallicornis on one of our peach trees (I had first noticed an adult of this species nibbling a black cherry leaf back on May 23 and later photographed one laying eggs). Peach is not a previously documented host, so I collected the mine to try and rear an adult, but instead I got this male eulophid (probably a Pnigalio) on June 30.
I noticed another four leafminer species for the first time on July 1.
Leafminer #95: Baliosus nervosus (Chrysomelidae). This beetle is known as the “basswood leafminer,” but it feeds on a number of other woody plants, including some of our fruit trees. There are a few mines just getting started on our medlar (Rosaceae: Mespilus germanica—or Crataegus germanica, depending on who you ask).
The holes at the edge of the mine are characteristic and were chewed by the female at the spot where she deposited the egg. This beetle has never been reared from medlar, nor reported from it other than on this one tree in my yard. I have collected the mines several times but they have always been parasitized. I reared this one last August from a hawthorn leaf collected on the other side of the yard:
Leafminer #96: Cremastobombycia solidaginis (Gracillariidae). A single leaf on a rough-stemmed goldenrod (Asteraceae: Solidago rugosa) by the chicken run had two underside tentiform mines of this moth.
As with Phyllonorycter species, which make similar mines on woody plants, Cremastobombycia larvae pupate within their mines. Unlike Phyllonorycter, they spin a distinctive spindle-shaped cocoon that is suspended within the mine like a hammock. The pupa is thrust through one end of the cocoon and through the lower epidermis when the adult emerges.
Leafminer #97: Ophiomya sp. (Agromyzidae). Well, a stem miner in this case. I noticed this mine on a yellow hawkweed (Asteraceae: Hieracium praealtum) right by my front door when I was heading out to get some food for some of the sawfly larvae that live on my desk.
This was a surprise, because no North American agromyzid fly is known to mine in hawkweed stems. Well, except for the as yet undetermined species that I’ve reared from native hawkweeds, but this is the first mine I’ve seen on an introduced hawkweed. And maybe more significantly, whereas the mines I’ve found on hawkweed before had a black puparium forming just a slight bump beneath the stem epidermis, in this one (and the others I found over the next 15 minutes of searching my yard) the puparium was concealed beneath a raised “scab” composed of dried latex from the plant.
This is reminiscent of the “scab” formed by an Ophiomyia species that feeds on wild lettuces (Lactuca spp.), first noticed by John van der Linden in Iowa. Once he posted photos on BugGuide and the rest of us knew to look for them, they were soon found by Mike Palmer in Oklahoma, Tracy Feldman in North Carolina, and myself in Maine and Massachusetts (including in my yard). It will be interesting to see if the hawkweed stem miner is the same species.
Leafminer #98: Leucospilapteryx venustella (Gracillariidae). A little white snakeroot (Asteraceae: Ageratina altissima) that we planted near the chicken house last fall now has numerous underside tentiform mines of this moth.
The mines of this species are much larger than those of Cremastobombycia species on other Asteraceae, and instead of pupating inside them the larvae turn bright red, chew their way out of the mines, and wander off to spin their cocoons somewhere else.
Also on July 1, I found out what those red eggs were that I collected along with the sawfly larvae on the little paper birch sapling next to the house on May 31—the eggs and a young caterpillar are shown near the top of this post. That caterpillar pupated in a tightly folded leaf margin a while ago, and on July 1 it emerged as an adult “arched hooktip” (Drepanidae: Drepana arcuata):
Here’s the leaf fold pried open to show its pupal skin:
Another emergence on July 1 was this male Liromyza (Agromyzidae):
I collected it as a larva mining a leaf of one of the Jerusalem artichokes (Asteraceae: Helianthus tuberosus) growing along the south side of our house. I didn’t mention it at the time (June 16) because I suspect it is Liriomyza arctii, which I had already found mining leaves of Heliopsis and Arctium earlier this spring. Liriomyza arctii has never been reared from Helianthus before, though, so now I’ll get to find out if my suspicion is correct.
Yet another adult that emerged on July 1 was this eulophid from a mine of Phytomyza origani on oregano. It’s probably a female Pnigalio; this is the most common parasitoid genus I rear from leafminers.
On July 2, the yellow-spotted paper birch sawfly larva (#23) I collected on June 18 emerged as an adult. It has surpassed Nematus appalachia as the greenest sawfly I have ever seen:
And so this post would have ended, had I not bumped into a few more things this evening right before dinner. When I was picking red raspberries from one of the wild plants I’ve been mowing around right by the clothesline, this sawfly larva fell into my hand—the 30th species for the year (whatever species it may be):
And then while picking greens for dinner in the lower vegetable garden, I found two more leafminers:
Leafminer #99: Pegomya sp. (Anthomyiidae), on lambsquarters (Amaranthaceae: Chenopodium album). I’ve found two other Pegomya species in the yard so far this year; one on curly dock (Rumex crispus) that is probably P. solennis, and one on spinach that is almost certainly P. hyoscyami. Although the latter has been reported to mine leaves of lambsquarters, this is clearly a different species because its eggs are completely smooth. It is likely P. atlanis, the species I’ve reared from lambsquarters in my yard in the past; unlike most Pegomya species, it has a single generation per year, and the larvae feeding now won’t emerge as adults until next spring. (There is a tiny mine of Chrysoesthia sexguttella just getting started at far left in the first photo below.)
Leafminer #100: Liriomyza brassicae (Agromyzidae), on nasturtium (Tropaeolaceae: Tropaeolum majus). In the leaf shown below, the larva switched back and forth between the upper and lower surfaces a couple of times.
And finally, I’ve sampled a few more edible plants from the yard over the past few days:
74. Black raspberry (Rosaceae: Rubus occidentalis) – fruit
75. Sweet goldenrod (Asteraceae: Solidago odora) – leaves
76. Onion (Amaryllidaceae: Allium cepa) – bulb
77. Daylily (Asphodelaceae: Hemerocallis fulva) – flowerbuds, flowers
Pingback: The Yard List(s), Part 20 | BugTracks
Pingback: The Yard List(s), Part 22 | BugTracks
Pingback: Can gall midges be leafminers? | BugTracks