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.