Baby bee odor lures cradle-robbing mites (bee parasite)

Baby bee odor lures cradle-robbing mites

French researchers have identified a compound tempting to a troublesome bee parasite. One whiff of this scent, emitted by honeybee larvae, sends a female bee mite scurrying toward it. The team suggests the chemical "could become the basis of new approaches" to controlling the tiny pest.

When female mites finish dining on an adult bee, they follow their "noses" to a honeycomb cell housing a bee larva, preferably a drone (male). There they find male mites, which spend their entire lives in the cells. The mites mate, and both adults and offspring feed on the body fluids of the bee larva. Feeding mites disrupt the larva's growth, sometimes sucking it dry and killing it. And in adult bees, mite bites invite secondary viral infections.

Researchers hold the mite responsible for the loss of hundreds of thousands of hives in Europe and Asia. It has yet to cause significant damage in the United States, where it first appeared in 1987. U.S. beekeepers control the intruders with pesticides, but biologists worry the species might develop resistance.

The mite, Varroa jacobsoni, attacks worker bees as well as drones of the Apis mellifera species, commonly called the European honeybee. Some researchers question whether the compound would serve as an effective bait to trap mites. Bee experts agree, however, that chemical baits hold promise.

The French team made extracts from whole drone and worker larvae and identified 10 potential attractants in them. They then placed female bee mites in the center of an X-shaped chamber. Each arm of the chamber wafted either plain air or one of three types of fragrance sources: live drone larvae, the larval extracts or commercial versions of the 10 compounds. Testing each mite individually and observing which arm it entered, the researchers found that plain air and seven of the compounds held no attraction. Many mites homed in on the live drone larvae and the extracts, preferring drone over worker extract. But the winner was an ester called methyl palmitate, the team reports in the Aug. 11 SCIENCE.

While the researchers have yet to field-test the alluring ester, they have set simple traps in laboratory hives, says coauthor Guy Ourisson of the Institut de Chimie des Substances Naturelles, in Gifsur-Yvette. "A piece of blotting paper impregnated [with methyl palmitate] and placed at the bottom of the beehive will attract mites," he told SCIENCE NEWS.