Monday, October 25, 2010

Sympathy for the devil?

It's because of Western yellow-jackets (Vespula pennsyvanica) that I no longer go outside without a hat. A couple of autumns ago, I was repeatedly dive-bombed by speeding yellow-jackets who proceeded to get tangled in my (very short) hair. The first time I thought it was a fly and tried to pick it out, only to get my fingers stung. The second time I beat the wasp and my head with a stick until it's mangled body fell to the ground. The third time I was able to prod it out with a stick. The fourth time I finally used my brains and wore a hat, which the yellow-jacket bounced off of and went on it's demented way.

These are the same merry insects that crash outdoor parties in the summer. It's quite amazing to watch one carve a small orb out of your meat dish and chow down or carry it away. However, they're not very good at sharing so we've learned to set a place for the yellow-jackets far away from our food. This actually seems to work most of the time, leading me to believe that they're chowing down and thinking, " How nice it is not to be bothered by the giant mammals for a change and, by the way, isn't this chicken just divine?"

Yellow-jackets only live one season and their time ends as the autumn winds down, so perhaps I can forgive them their wild attacks at this time of year. With my hat in place I can afford some magnanimity toward them.

This summer I've kept my eye on a nest of yellow jackets, in the ground, near one of the trails at Howarth Park that I frequently walk. I tried to observe the goings on but whenever I stopped, at a healthy distance, to look with my binoculars a few would head my way and start buzzing me in a way that just didn't seem friendly. About two weeks ago small rocks began appearing in the opening to the nest. The yellow-jackets dodged them the best they could and continued to come and go. Sometimes the rocks were removed and other times more were added. It seemed very odd and I tried to imagine the courage or stupidity it would take to stand close enough to put the rock in the opening. As the mornings grew chillier, I noticed that the wasps weren't very active so maybe it was someone roaming at night or earlier in the morning than I.

It remained a small mystery in the back of my head but one that I mostly forgot about until near the end of September, when  I found that the opening had been dug wider and there was honeycomb scattered everywhere with what I discovered were larvae within. Several of the larvae were being carried off by ants and a few adult yellow-jackets walked about the ground looking dazed. I was able to get quite close without any attacks. I really couldn't imagine why any human would want to risk life and limb and dig out a yellow-jacket nest. I made some sketches and notes and looked forward to trying to untangle the mystery.

Continuing my trek, I noticed some raccoon scat in the trail, not an unusual sight, but I began to wonder if, for some crazy reason, a raccoon or other mammal had been the digger. As it turns out, it may have been. Apparently, yellow-jacket larvae are mighty fine eating in some circles. Raccoons, skunks and possums are known to dig up these nests and feast on the larvae. So, that mystery....solved.

I still had one other mystery to solve, though. If yellow jackets die at the end of summer why was this nest full of larvae? As it happens, each spring, a single female queen that has overwintered begins to build a nest and lay eggs that become the workers who, in turn, take over nest building and provisioning as the queen lays more eggs, creating more wasps to populate the colony. At the end of summer she lays another set of eggs that will become fertile females who, in turn, go off and find a safe place to spend the winter before beginning their own new nests. I find myself feeling sympathetic toward this group of Yellow-jackets. They worked all summer, took care of their young, only to lose them in a moment. Hmm.

For more information and pictures visit:
The adventurous gardener
The Yellow Jacket Wasp
Bug Guide

1 comment:

  1. Wonderful post! Lucky you getting to see the inside of a yellowjacket nest without putting on a moon suit. I found a nest the other day and had fun trying to photo the yellowjackets entering and leaving.

    We also try to bribe the yellowjackets by giving them their own portion. We love to buy a whole salmon when we are at the coast. When Dale cuts the fish up, the head gets set about 15 feet away in the hopes that will keep the little darlings busy.