Like the Little Pig who made his house out of Straw, we have wasps that make their nests out of straw too. Our Isodontia wasps use only Grass to create their cell partitions and nest plugs. These inch-long gentle giants use some of our largest tunnels. While Isodontia don’t start nesting until well into the summer, they can produce two generations per year and will nest until our first frost.
If you see an Isodontia wasp, please let us know if she was black or rusty- orange, as that will tell us what species you have. The black ones are Isodontia mexicana and the rusty orange ones are Isodontia elegans. There seem to be some differences in their nesting. I. mexicana seem to come out a week or two before I. elegans, nest in slightly smaller tunnels, and make severely protruding nest plugs. It is possible for both species to nest in the same block at the same time!
Unlike bees that provision their nests with pollen, these wasps collect tree crickets (or sometimes young katydids) as food for their babies to feast upon. If you see your wasp dragging home a pale green blob, you’ll know her young will feed well.