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Archive for December 21, 2011

Mud Dauber Wasp Nest

There are many species of mud dauber wasps in New England that use mud to make cells for their eggs, developing larvae and pupae.  One of them is Pison koreense, a small, black wasp with a wingspread of less than half an inch.  This particular wasp is native to Korea, China and Japan, and was accidentally introduced in the United States after World War II.  Like other mud daubers, this wasp constructs one cell at a time with her mandibles; there can be anywhere from 1 to 12 mud cells (each roughly ¼” long) in a nest, which is often located in a crevice or behind bark.  She then hunts for spiders, stinging and paralyzing them before carrying them back to the cell, into which she stuffs them.  After collecting 20 – 30 spiders, she lays a tiny white egg on the last (and often largest) spider to be placed in the cell.  She then flies off and collects mud with which she seals the cell.   The egg hatches, the wasp larva consumes the live spiders and then pupates, spending the winter inside a cocoon inside the mud cell.  In the spring the adult wasp emerges from the cocoon and chews her way out of the cell, leaving a circular exit hole.