Saturday, June 16, 2012

Mason Bee Parasite

Wasps in the genus Gasteruption are social parasites other Hymenoptera. In this case that means Mason Bees. They inject their egg into the mason bee tunnel where larva of the host species are developing. Next year, instead of hatching as a mason bee, a parasitic wasp will emerge.

The fact that I'm seeing these in the garden should probably be a red flag to bring the mason bee nest blocks inside or at least screen them in somehow. My mason bees are an invasive species though, Osmia taurus, so I'm not really inclined to do that. In the interest of diversity I think I'll let nature takes its course, assuming they are the host that is.

I'm amazed at how pencil thin they are. They even look tiny among the blooms of New Jersey Tea, Ceanothus americanus.