Bug box: Yellow jacket

The genus Vespa comprises about 20 species, most of which are native to tropical Asia, but there is a species found across temperate Eurasia including Japan. Yellowjackets were in the area these past weeks. Yellowjackets are generally smaller than hornets and are bright yellow and black, whereas hornets may be darker in color – see wasp and bee characteristics. (Wikipedia).

There are three types of hornets:

The striped o-suzumebachi, or the vespa mandarina, known as the giant hornet, builds hives underground or in tree hollows.

The kiiro-suzumebachi, the vespa xanthoptera, or the Japanese yellow hornet, builds hives under the eaves of houses, or the space under bridges.

The kuro-suzumebachi, vespula lewisi, that are smaller than the other two.

read this article about Nagano prefecture’s vespa delicacies.

Just this week, a nest was fumigated in our neighborhood and we were told to stay indoors or lie low. These photos were taken nearby my home, except for the last one which was in my room where I caught the yellow hornet.

Yellowjackets, in particular, may be late season pests around picnics, trash cans, and humming bird feeders as they scavenge. The only way to control this situation is to locate and destroy the nest, which is rarely possible. As an alternative, keep all outdoor food and drinks covered, except while actually eating. (see Beekeeping Insect Note #15, Reducing the Likelihood of Stings During Outdoor Activities). Bee guards or a coating of petroleum based chest rub can be used on hummingbird feeders where the insects land. Trash cans should be kept covered or have a flap over the opening. Defensive behavior occurs in response to nest defense. If the nest is not in the immediate vicinity the likelihood of stings is greatly reduced.

Two points to remember:

• In spite of their reputations, hornets and yellowjackets are actually beneficial because they prey on many insects that we consider to be pests. They also serve as food for other bears, skunks, birds, and other insects.
• Unlike honey bees, hornet and yellowjacket colonies die out each year.

If a hornet nest is built high in a tree, you may choose to simply wait until the colony dies out in late fall or early winter. The nest will slowly deteriorate from weather or from attack by hungry birds. If a nest is located where people may be stung or if you (or others) are hypersensitive to bee/wasp stings, then colony destruction may be appropriate. Control is best achieved by applying a pesticide directly into the nest opening. This can be done at anytime of the day, but near dusk, most of the wasps are more likely to be inside the nest.