When most of us think of wasps, we are really thinking about members of the Vespidae family, the colonial wasps. They are the most common and the ones we most often notice. According to David and Norma Barr, “There are only three main kinds of vespid or colonial wasps in North America … yellowjackets, paperwasps, and the Bald-faced Hornet. Unfortunately, these common names have become hopelessly mixed up through local usage.”
Yellowjacket can be “any of the 20 or so North American species of small, bright yellow-and-black wasps that build almost perfectly spherical paper nests either in cavities underground or (less frequently) hanging from a tree branch attached only by a narrow stalk at the top.”
Yellowjackets are most commonly sighted during late summer and fall when food sources decline and the worker wasps — now numbering in the thousands and no longer busy in their colonies — spread out over backyards, picnic sites, and anywhere else they sense available food. At this time of year, they also seem more aggressive and unpredictable. Even so, “their pest status is limited only to a few weeks in late summer and fall, and at that time the chance of multiple stings is not great.”
At the FWG, we didn’t notice yellowjackets at all until early September when we were working in our Butterfly Meadow. Several volunteer have inadvertently disturbed an underground nest while weeding there and have been stung badly. The stings are quite painful and itch for days to weeks afterward.
The nest at the left was discovered in our Old Field, right on the ground. It’s quite large – almost 30 cm in diameter.