The Urban Pantheist

This wasp, which I am pretty sure is a bald-faced hornet, was swimming in a trap made of a container of acetic acid when I came upon it and saved its life. The trap has three different lures designed to attract social wasps. I was using these traps to catch yellow jacket queens in the spring before they established nests. My tests showed that one of these three was best at catching the wasps I was after, so from now on I'll use that lure exclusively. The acetic acid lure caught no queens, several workers, and an amazing amount of non-target organisms: non-pest wasps, moths, crane flies, spiders, earwigs, and so on.

The trap I used is labeled for catching bald-faced hornets, but I'm not interested in catching them. They usually build their nests high out of reach of humans (as opposed to yellow jackets and European paper wasps which build nests in harm's way more often than not) and they are the only species I know of that actually preys on yellow jackets. (That's a very close kinship between predator and prey, by the way, the equivalent of Homo sapiens eating that little hominid in Indonesia, or a bullfrog eating a green frog.)

So when I saw her swimming in vinegar, waiting for the acid to clog her spiracles and drown her, I dumped out the trap and let this wasp dry out and get on with her life. Pest control isn't all about the killing.

Photo by cottonmanifesto. Location: Olmsted Park, Boston.
Urban species #258: Bumblebee Bombus pennsylvanicus

Until this year, I assumed I was seeing bumblebees almost every warm day of every year, and then I discovered I was actually seeing carpenter bees. One easy way to tell the difference is that the bumblebees have furry abdomens while carpenter bees have shiny black hairless abdomen. Bumblebees are familiar, almost friendly-seeming, with their thick fur and clumsy way about them. Their yellow and black markings, like those of many other stinging insects, are meant to warn predators. Stinging hymenopterans (that is, members of the order of insects that includes bees, wasps, ants, and others) are armed with venom-injecting weapon derived from their ovipositor. This means that only females can sting. Bumblebees are considered unaggressive and unlikely to sting. Like their close relatives, the honeybees, bumblebees are social, a hive of up to 300 individuals and their mother, the queen, working cooperatively to raise the next generation. Unlike honeybees, bumblebee colonies do not overwinter; only the queen (or her successor) survives. Bumblebees are highly valued as pollinators, with some plant nurseries and farms purchasing hives for this purpose; their small untidy combs not producing enough honey to make collecting it very rewarding.


Photo by cottonmanifesto. Location: our front step.

Urban species #259: White-faced hornet Dolichovespula maculata

Even this entomophile shudders a little bit at the sight of a swarm of white-faced hornets (also called "bald-faced hornets"). These wasps are very aggressive, and deliver a painful sting. Their large gray paper nests are often attached to buildings, although they also can be found in trees. Each nest, which can be a foot in diameter or more, is made of several layers of chewed wood, and contains between dozens and hundreds of individuals. The larva are fed flower nectar, and the bodies of other insects that the adults have killed and chewed into bits. White-faced hornets are ambitious predators, even attacking large and dangerous prey like their close relatives, the yellowjackets. Despite the danger of their sting, these insects are beneficial, preying on pests, and acting as pollinators. White-faced hornets are found across North America, except for the dry interior plains, and are common in urban parks and suburban neighborhoods.