The Bug Box: Varroa mite

University of Minnesota

University of Kentucky

This bug is creeping around your property. He may be friend or foe.

Name: Varroa jacobsoni

Alias: Varroa mite. These mites are very small pests of honeybees. The adult females are reddish-brown, flattened, oval and measure about 1 to 1.5 mm across. Males are slightly smaller and are tan. They are related to spiders and have eight legs. These mites were first reported in Java in 1904. They were discovered in the U.S. in 1987 in Wisconsin and Florida and since have spread throughout the U.S. The dark mites are easily seen on the white pupae when the honeycomb is broken or the pupae are pulled from their cells. Their flattened shape allows them to hide between the adult bee’s abdominal segments. They prefer feeding on drones (male bees), but will feed on the other castes in the hive, as well as several other species of bees. The female mite enters the egg cell just before it is capped. As the bee larvae develops, the mite eggs hatch and begin feeding. The mites mate inside the cells. When the bee emerges from its cell, some of the mites have also reached adulthood and find other bees and cells to infest. The mites spread from colony to colony by drifting workers and drones. Honeybees can also become contaminated when they rob smaller colonies.

Crimes: These mites suck blood from bees and cause weight loss, deformities, diseases and reduced lifespan. They can nearly destroy an entire colony of bees in a matter of months.

Redeeming Qualities: None known.

Sentence: If you are a hobbyist beekeeper you should be aware of the threat of this mite to commercial producers. There are pesticides available that are effective against this pest. Recently, the USDA has found a new biocontrol organism, a fungus that gives effective control of these pests.

For more information on dangerous and beneficial bugs, call agent Wayne Jones at the Bonneville County Extension Office at 208-529-1390.