Category Archives: Wasps and Bees

Tobacco Hornworm et al.

It’s not unusual for gardeners to find large caterpillars of the Tobacco Hornworm munching on their tomato or pepper plants.  Hornworm caterpillars get their name from the horn-like structure at the back end of the insect and while many species of hornworm caterpillars are known from Wisconsin, the tobacco hornworm is one of the largest and can reach lengths of over 3″.  If all goes well, the caterpillars eventually transform into large, grayish sphinx moths with a series of yellowish dots on the sides of the abdomen.

However, tiny parasitic wasps will sometimes kill a caterpillar before it can turn into an adult moth.  Female Cotesia wasps inject eggs into a tobacco hornworm caterpillar and the developing wasp larvae live as internal parasites.  At a certain point, the wasp larvae have matured and move to the outside of the caterpillar to spin silken cocoons and transform into adult wasps.  Biological control in action!

Tobacco hornworm caterpillar with dozen of cocoons from parasitic wasps. Photo courtesy of Deb Zaring.

It’s a fly, it’s a wasp, it’s a bee?. . .

One of the most unusual bees I’ve ever seen was brought in by our fruit crop entomologist earlier today.  Its behavior had been described as somewhat “fly-like”, although the abdomen had a color pattern that screamed “yellowjacket”.  It was hairy like most bees, but possessed some unusual hook-like appendages from the tip of the abdomen.  After some digging, I was able to identify the species as Anthidium manicatum, commonly known as the “European wool-carder bee”.  It happens to be a European species that was introduced to the US back in the 60’s and is now widespread. The species gets its name because females collect hair-like fibers from plants to line their nests.

Anthidium manicatum, the "European wool carder bee"
Anthidium manicatum, the “European wool-carder bee”. Photo credit: PJ Liesch