Grass-Carrying Wasp

Description:

Isodontia species are members of the thread-waisted wasps. I haven't been able to get close enough or get a good enough photograph to identify this particular species. The most common species here is Isodontia apicalis. They are also known as bird-nest wasps, due to the type of brood chamber they construct. Each cell is provisioned with a particular insect, such as a cricket or katydid.

Habitat:

I took this photo in a suburban yard bordered by mature trees and deciduous forest.

Notes:

This photo isn't the best--the wasp is blurred slightly--but its behavior is fascinating. The Isodontia species carries grass to its brood cavity, which are natural cavities in wood or between rocks, to help protect its brood. I've caught glimpses of this insect before and intially thought they were pelecinid wasps, which have extremely long ovipositors, but then realized they were smaller wasps carrying grass blades. As the weather has cooled here in Minnesota I've turned off the air conditioning and am ventilating the house by opening the windows. Much to my surprise these wasps have been stuffing grass blades into the recessed cavities around the window openings. I've seen this deposition of grass once before and wondered where it came from. Now I know....fascinating. Now to try and get a better photograph.... The wasp in the photo is carrying grass to a small cavity in the edge of our garden shed's roof.