Pelecinid Wasp – Welcome to a photographic journey through the woods, fields and marshes of New England
Find more of my photographs and information similar to that which I post in this blog in my book Naturally Curious, which is being published this fall.
PELECINID WASP
If you see a shiny, black, slow-flying wasp with a disproportionately long abdomen crawling on your lawn in late July, August or September, you should shout for joy. It is North America’s one species of pelecinid wasp, and it is a parasitoid – an insect with larvae that complete their development at the expense of a single host organism that is killed in the process. Using her long, flexible abdomen the female pelecinid wasp lays her eggs in June beetle larvae (which are busy consuming plant roots beneath your lawn). These eggs will hatch into wasp larvae that will devour their host, thereby decreasing next year’s June beetle infestation.
Naturally Curious with Mary Holland 
Wow what a photo!!!!! Do they sting too? They are marvelous to look at though I’m not sure I have ever seen one except here. I sure am going to look for one. Thanks so much for heightening my awareness so many times!!!!
August 4, 2010 at 7:56 pm
Great timing! I went out to inspect our crop of milkweed and not yet! No egg case. but plenty of Monarchs. If they first eat the hairs, then go to work on the leaf, when do they wrap it up and call it a day (hibernate)?
August 9, 2010 at 2:20 pm
We bought some property in Crivits Wisconsin this last summer and had several of these flying around. I was told that they were highly dangerous, that one sting could kill you????
January 11, 2013 at 8:17 pm
It’s my understanding that Pelecinid wasps do not sting — they use their ovipositor strictly for laying eggs, I believe.
January 11, 2013 at 9:06 pm
one of these things flew down my shirt, I freaked the hell out. I had no idea what it was.
September 9, 2013 at 9:29 pm
One of these dragon-like spidery creatures landed on my pant leg at the cottage this weekend (White Lake, Ontario, Canada). I managed to escape without damaging it and I took its picture. The Internet (and your post) helped me figure out just what it was. Thank you!
August 29, 2015 at 7:55 pm
Amazing insects, aren’t they? Will be posting about them in the next week or two!
August 30, 2015 at 7:27 am
PS – I write for kids, too, but nothing on the scale you do. My area is healthy eating / nutrition for growing families. I’m impressed with your body of work!!!
August 29, 2015 at 7:58 pm