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Posts tagged “Sphecidae

Thread-waisted Wasps Provisioning Nests

8-21-17 thread-waisted wasp by Mardie FullSizeRender (002)

There are over 1,000 North American species of solitary hunting wasps. All of them prey on arthropods, which the female stings and paralyzes (but doesn’t kill so that they don’t begin to decompose immediately). Most solitary wasps specialize on a single type of prey, and many build highly characteristic burrow nests. Once the prey is stung, the wasp carries it back to her nest where she then lays a single egg and closes up the nest. The developing wasp larva feeds on the paralyzed prey, pupates and emerges as an adult wasp.

One group of solitary hunting wasps is referred to as thread-waisted wasps (family Sphecidae), due to their long, stalk-like waists. While most close up their nests (by kicking sand over the entrance) after stocking it with prey and laying an egg, some species close their nest with a pebble and return, remove the pebble, and periodically restock the nest with fresh caterpillars for the growing larva. (Photo by Mardie Holland: thread-waisted sphecid wasp with caterpillar prey)


Inside Look at Organ Pipe Mud Dauber Wasp Cells

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Each “pipe” of the Organ Pipe Mud Dauber nest consists of several sealed cells (four, in this photograph), each stuffed with spiders (typically orb-spinning spider species) and one wasp egg. When the egg hatches, the white wasp larva consumes the paralyzed spiders, which are still fresh because they are still alive. Eventually, upon finishing the spiders, the larva will form a pupa case, and spend the winter inside it. In the spring the adult wasp will emerge from the case and chew its way out of the mud cell. If you look closely at the open, back side of these three “pipes” you can see that the oldest pipe is on the left, and contains cells with wasp larvae, whereas you can see mud dauber eggs lying on top of the spiders in two of the cells on the far right, in the most recently built pipe.