Monday, September 22, 2014

Outcast Wasps

This is a male Polistes fuscatus, the Northern Paper Wasp.  It is part of the group of wasps that creates the paper nests commonly found beneath the eves of houses, on porch ceilings and above door jambs and window openings.  I encounter more nests of Polistes species than of all other wasp species combined.

I find Northern Paper Wasp nests in many locations.  Each nest is active for only one summer season.  The nest begins in spring with initial construction by the founding queen and dies in the fall when newly produced queens leave to mate and find a place to spend the winter.  For the past several years, wasps have constructed their nests inside the hollow spaces in the blocks used to create my barn walls.  Access to the interior of the blocks is through these two holes that, at some pre Blue Jay Barrens time, held mounts for some type of apparatus secured to the side of the barn.  I’ve never seen the actual nests inside the blocks, but I’ve become accustomed to the cycle of wasp activity around the holes.

The nest is approaching the end of its life.  The queen has stopped laying eggs.  She and her squad of workers are dead or dieing.  The bulk of nest occupants are males and unfertilized queens.  As the number of workers decreases, the flow of food to the nest is interrupted.  When the food supply diminishes, the female wasps respond by driving the males away from the nest.  The first light of day reveals male wasps being given the boot.  They struggle to remain inside, but the relentless females use as much force as necessary to push the males out.

Male wasps, identified by their curled antennae and light colored faces, loiter in the area around the hole.  The faces of the next group to be turned out can be seen at the entrance to the hole.

The wasps don’t go far from the nest.  They will spend most of the day lounging on the wall.  Occasional forays are made to a nearby water source.
The males spend considerable time socializing.  Some of the activity appears to be an attempt to solicit food from each other.  While in the nest they would have been fed by worker females who spent much of their life foraging.

The function of a male wasp is to mate with a female.  At this time of year they will attempt to mate with any wasp, male or female, that comes by.  A wasp flying to the wall arouses an instant mob of males.  Males are attracted to concentrations of females.  As long as the young females are still present in the nest, the males will stay close.  The females will soon leave to find suitable hibernation sites.  The males will follow and at that time will interact and mate with females from other nests.  Males will not survive the coming cold weather.

As temperatures drop with the setting of the sun, the males are allowed back into the nest.  The time is rapidly approaching when the wasps will be absent and the buzzing inside the wall will cease.  I expect next summer to again see the familiar flight of wasps flying to and from these holes.