Wednesday 8 July 2015

American Pelecinid Wasp

Image: Andreas Kay
Pelecinus polyturator
This is a wasp that simply doesn't know when to stop!

Image: hspauldi
The American Pelecinid is a distinctive wasp that can be found from southern Canada all the way down to Argentina.

They reach just over 6 cm (2 and a half inches) long, the vast majority of that length taken up by a long, extremely thin abdomen.

Luckily, that abdomen is nice and bendy so the wasp can curl it up out of the way while she walks and flies around in search of sweet, energising nectar.

She also goes through all manner of gymnastic contortions when she grooms herself. Nice scrubbing brush, that's what she needs. Or a broom.

But all this is just the female...

Image: Andreas Kay
Males are about half her size and have a much more humdrum, club-shaped body. Booooring!

Alas, the female's extraordinary abdomen is not there simply to look extraordinary. It has work to do. She uses it to delve into soil so she can rummage around and find the plump larva of a June Beetle. She deposits one of her own eggs, leaving it to hatch and feast upon the unfortunate grub.

Image: Pascal Gaudette
Soon a fresh American Pelecinid Wasp will emerge from the ground, shiny and new. If you're in the right part of the world, it seems it will almost certainly be a female. Males appear to dislike the cold - while they're quite common in the warm, tropical parts of their range, they're scarcely ever seen in North America.

If males really are as rare as they appear in the north, it would mean that a whole lot of American Pelecinid Wasp are capable of parthenogenesis, or virgin birth! Males need not apply.

That's what you get for having such a boring abdomen...


Crunchy said...

My mom always warned me no one would ever love me unless I fancied up my abdomen... Why didn't I listen!?

Joseph JG said...



I had a few.

Joey said...

When I was a kid back in the early 50s, we used to see these often on the east side of Detrit MI. We used to play with them, and called them "Sewing Bugs".