Wednesday, August 25, 2010
Our front yard has plants that attract honey bees (Apis mellifera), California carpenter bees (Xylocopa sp.) and the paper wasps (Polistes dominula). On sunny afternoons they all buzz harmoniously about some sages and oregano, drinking nectar. I've also noticed that the wasps spend a good deal of time visiting our lettuce patch, landing on the leaves and moving about for a minute or less then leaving. During our heat wave the wasps, and only the wasps, have been drinking and lounging in the water in our little bird baths. There seem to be three approaches: 1) fly by, dip toes in water, then land on edge of container and drink, 2) drop onto the water and float for a bit while sipping, 3) hover above the water, dipping frequently to sip. The wasps appeared to be utterly unconcerned by my presence. I sketched some more this afternoon, as the coastal influence began to reestablish itself (the fog's returning!), and was interested to note that the wasps stopped drinking from the bath when the temperature dropped into the mid- or low 90s.
These wasps are recent immigrants to our continent. Natives of Europe, they somehow found their way to Massachusetts in 1981 and then spread across the country with great haste. In some areas of the northeast they appear to be replacing native paper wasps. Their long hind legs and slender bodies make it easy to distinguish them from the similar looking yellow jacket (Vespula sp.).
Oh, and as to why they hang out in our lettuce? We often water it at noon on warm days. I suspect that the wasps find the sheltered, shaded source of water appealing at that time of day.
For more information than you'll ever need about European paper wasps, check out these web sites:
Living with bugs
Penn State College of Agricultural Sciences
Michigan State University
Garden Friends & Foes
Bug of the month: Articles about Pacific Northwest Insects