Big Blue Flying Insect
August 17, 2009
These bugs are living in a stone wall where I work in Rhinebeck, NY (it is summer right now). They fly out and bring back grasshoppers that seem to be paralyzed when they bring them back to the wall. They disappear with them in the wall and then a few days or weeks later (not sure) they drop the shell of the grasshopper out of the wall-like the entire inside has been eaten out.aaaaaaaa
This is one of two species of Thread Waist Wasps that we have trouble distinguishing from one another. We believe it is a Blue Mud Wasp, Chalybion californicum, which according to BugGuide is : “A large, active, blue-black wasp with irridescent blue wings. Frequents flowers for nectar and buildings for nest sites. Compare “Steel-Blue Cricket Hunter”, (or “Blue Mud Dauber”), Chlorion aerarium, which preys on crickets. This is about the same size as Chalybion, and is said to have a longer pedicel (narrow waist between thorax and abdomen). The body of Chalybion looks much more hairy, and more steely-blue, based on specimen photos.” The other possibility is that it is Chlorion aerarium, also depicted on BugGuide. which states: “Habitat Although generally not closely associated with humans, they are found wherever their hosts (Gryllus crickets) are found, which could include close proximity to homes (though not so much as Sceliphron and Chalybion). Chlorion is usually found in open areas such as meadows, overgrown fields, dunes, beach edges, etc., although they may not necessarily hunt in the same habitat as they nest. They are sometimes associated with the Cicada Killer where the ranges of these two wasps overlap, C. aerarium digging burrows off side of the larger wasps nest (O’Brien, 1989).
Season Late July and early August (in Michigan)
Remarks Females mass-provision several serial cells, each containing from 2 to 9 nymphs or adults of Gryllus pennsylvanicus. Prey are transported on the ground, venter-up, with the wasp’s mandibles grasping the antennae of the cricket.“ It is worth noting that the adults of both species feed on nectar and pollen, and the crickets are used as food for the brood. We will contact Eric Eaton to see if he can provide the exact identification.
Ok, here are all the identifications:
The “blue mud dauber” or “Chlorion” is neither. These are two nice images of a female “great black wasp,” Sphex pensylvanicus. They hunt katydids as food for their larval offspring, as the submitter observed.
Keep up the great work!