About a week ago I was checking on the two asian pear trees that are growing in the yard to see how soon I could start harvest pears. I was surprised to see that a number of the pears had been partially eaten by a wasp or hornet that I’d never seen before. It was a very handsome insect – that is if you’ll allow insects to be called handsome – with a black body and white markings.
After a little searching, I learned that these pear eaters are baldfaced hornets (Dolichovespula maculata). They get their name from the white markings on their heads. While they’re called “hornets,” these insects aren’t true hornets but are instead yellowjackets.
Baldfaced hornets are found in all of North America and live in papery nests that are found in trees or bushes, though they can be built under the eaves of building. These nests can be up to 2′ high and 18″ wide. At the center of the nest is the queen and the mission of all of the workers is to feed the larva. In the spring and early summer baldfaced hornets focus on finding protein sources for the developing larvae. The primary sources of this protein are flies, other yellowjackets and a variety of other insects. As the season goes on, there are fewer larvae to fed so the baldfaced hornets turn to nectar and other sources of carbohydrates.
It was the free source of carbohydrates that drew these insects to the asian pears. The fruit had just begun to ripen but it was ripe enough for them. While I don’t like losing fruit to the baldfaced hornet, after a season of them killing flies, yellowjackets and other insects, I’m willing to overlook a few lost pears.
Baldfaced hornets can sting and, like other yellowjackets, they have a smooth stinger so they can sting repeatedly. While there is some danger of being stung, the baldfaced hornet is in truth a beneficial insect. It kills unwanted insects and, when it’s searching for nectar, it helps to pollinate flowers.
On the day I noticed this insect I harvested all of the undamaged pears. Since that time I haven’t seen another baldfaced hornet. But I’ll be expecting their return next summer to let me know when the pears are getting ripe.