Over the past few days, a break in fieldwork has given me a chance to start catching up on going through my photos from this year—I’m exactly five months behind at the moment. On March 19 I finally got to the end of a story that started with the Berkshire BioBlitz on June 19 of the previous year. I had collected this leaf of silky willow (Salix sericea) in the hope of finding out which of the nine willow-feeding species of Phyllonorycter (Gracillariidae) was responsible for the leaf mine on it, since as far as I know there is no way to distinguish among the mines of these species (though a few can be ruled out based on geography).
In my hurry to document as many species as possible in a short time, I didn’t investigate what had made the webbing and leaf fold next to the mine. This nearly proved disastrous, since it turned out a caterpillar was hiding in the leaf flap, and by the next day it had consumed much of the leaf. Fortunately, it didn’t eat too much of the mined portion.
I moved the caterpillar to a separate vial with fresh willow leaves. I don’t usually collect non-micro moth caterpillars to rear, but when they show up on leaves I’ve already collected I figure I might as well.
On June 28, the adult leafminer emerged, revealing itself to be Phyllonorycter salicifoliella, and leaving its pupal skin protruding from the mine.
The externally feeding caterpillar developed much more slowly, and I had to keep collecting new willow leaves to feed it. Here it is on July 6 with an old willow leaf that has gone yellow:
On July 29 it was looking pretty different:
The last photo I took of it was on August 4…
…but I noted in my journal that it turned pink and burrowed into soil on August 12. As it happens, I had tried to rear this same species eleven years earlier (from a caterpillar feeding on black cherry), so I have a photo to illustrate just how pink it was when ready to pupate:
Nothing stirred in the jar for the rest of the year. I put it in the fridge over the winter, taking it back out on March 1. Almost three weeks later, an adult confused woodgrain (Noctuidae: Morrisonia confusa) appeared in the jar. Having no further use for it, I let it out to see if it could find others of its kind. Here it is resting on a fallen white pine at the edge of my yard:
