A big “thank you” to my first 13 patrons! I’m almost done writing the main introductory chapter that I’ve been putting off dealing with for a few years now, and soon I’ll get to work trying to put together a reasonable summary of the various groups of wasps that parasitize leafminers… which reminded me of a couple of wasps I got to watch develop this year, so I thought I’d share the photos here.
On September 16 Julia and I participated in this year’s Berkshire BioBlitz in Great Barrington, MA, naturally focusing on the galls and leaf mines that no one else was going to look at. When we encountered some mines of nepticulid moths on black birch (Betula lenta) leaves, we were compelled to collect them and try to rear them out, because there is a bewildering array of similar mines on birches that still need some sorting out. As I was taking a backlit photograph of each mine that still contained a larva, I saw that this one had a problem:
Namely, it had an ectoparasitoid chomping on its back.
The following night, all that remained of the moth larva were its head capsule and (please correct me if I’m wrong) Malpighian tubules, and the wasp larva had begun to wander back down the mine channel.
It continued to work its way back until the next morning.
A day later, it had backed up just a little bit (you can faintly see its pointy posterior end crossing the moth larva’s frass line in the photo below), and its gut contents had visibly consolidated.
Another day later, it had finally pupated, depositing its shed skin and meconium (all of the accumulated waste products from its life as a larva) in a heap where the tip of its abdomen had been the day before.
Eight days after that, the adult wasp had chewed its way out of the leaf, leaving its pupal exuviae behind.
This is a eulophid wasp, very similar to this one that Christer Hansson identified as Pnigalio flavipes. That was before he examined more of my reared eulophids and decided that the whole genus Pnigalio is in serious need of revision because, for instance, males and females that clearly belong to the same species key out to different species using the existing keys.
I’ll save the other wasp rearing series for another day!