Hello again, Daniel.
Apologies for two messages in one day, but our earlier correspondence reminded me of something. Back on June 25th I sent you a couple of photos of a questionmark caterpillar that I’d mentioned had later been parasitized by a tachinid fly, which was also raising havoc with my monarch caterpillars. In answer to your request, I had to say I hadn’t photographed the fly.
Anyway, since then, I’ve kept several of the little maggoty buggers in a medicine bottle, allowed a few to emerge, and then put them in the freezer. I remembered today, after another monarch was killed. Here’s a mug shot. The “pills” are their pupal cases. I don’t know the species, and I don’t care!
Like so many of these flies, they emerge when the caterpillar is in the process of going into it’s pupal stage, or sometimes even after the chysalis is formed. Then the maggot comes out, and rappels to the ground on a long filament, and upon finding a spot to it’s liking, becomes a pupa itself.
I understand these amazing creatures role in the natural world. I’ve read alot about their incredible lifecycle. But I love moths and butterflies more, and these little monsters seem to take perverse pleasure in killing my favorites right at their peak, after they’ve gone through their entire laval stage. I hate them!
Anyway . . .
Cheers, and thanks very much for all you do.
Don J. Dinndorf
St. Augusta (central), Minnesota
Thank you for providing such an educational posting on the life cycle of Tachinid Flies for our readership.