Bees Throw Out Mites

Sep 11, 2009 By Alfredo Flores
Bees Throw Out Mites
ARS researchers have developed honey bees that more aggressively deal with varroa mites, a parasite that is one of the major problems damaging honey bees today.

Honey bees are now fighting back aggressively against Varroa mites, thanks to Agricultural Research Service (ARS) efforts to develop bees with a genetic trait that allows them to more easily find the mites and toss them out of the broodnest.

The parasitic Varroa mite attacks the honey bee, Apis mellifera L., by feeding on its hemolymph, which is the combination of blood and fluid inside a bee. Colonies can be weakened or killed, depending on the severity of the infestation. Most colonies eventually die from varroa infestation if left untreated.

Varroa-sensitive hygiene (VSH) is a genetic trait of the honey bee that allows it to remove mite-infested pupae from the capped brood—developing that are sealed inside cells of the comb with a protective layer of wax. The mites are sometimes difficult for the bees to locate, since they attack the bee brood while these developing bees are inside the capped cells.

This video is not supported by your browser at this time.
Audio Podcast: The Mitey Bee Bouncers

ARS scientists at the agency’s Breeding, Genetics and Physiology Research Unit in Baton Rouge, La., have developed honey bees with high expression of the VSH trait. Honey bees are naturally hygienic, and they often remove diseased brood from their nests. VSH is a specific form of nest cleaning focused on removing varroa-infested pupae. The VSH honey bees are quite aggressive in their pursuit of the mites. The bees gang up, chew and cut through the cap, lift out the infected brood and their mites, and discard them from the broodnest.

This hygiene kills the frail mite offspring, which greatly reduces the lifetime reproductive output of the mother mite. The mother mite may survive the ordeal and try to reproduce in brood again, only to undergo similar treatment by the bees.

To test the varroa resistance of VSH bees, the Baton Rouge team conducted field trials using 40 colonies with varying levels of VSH. Mite population growth was significantly lower in VSH and hybrid colonies than in bee colonies without VSH. Hybrid colonies had half the VSH genes normally found in pure VSH bees, but they still retained significant varroa resistance. Simpler ways for bee breeders to measure VSH behavior in colonies were also developed in this study.

This research was published in the Journal of Apicultural Research and Bee World.

Provided by Agricultural Research Service

Explore further: Alternate mechanism of species formation picks up support, thanks to a South American ant

add to favorites email to friend print save as pdf

Related Stories

Bee disease a mystery

Jun 30, 2008

Scientists are one step closer to understanding the recent demise of billions of honey bees after making an important discovery about the transmission of a common bee virus. Deformed wing virus (DWV) is passed between adult ...

Fungus Foot Baths Could Save Bees

Jul 28, 2008

One of the biggest world wide threats to honey bees, the varroa mite, could soon be about to meet its nemesis. Researchers at the University of Warwick are examining naturally occurring fungi that kill the varroa mite. They ...

Asian bees threaten Australia

Jun 15, 2007

Four swarms of Asian bees found in Cairns, Australia, may pose a serious threat to the country's honey bee population.

Bee species outnumber mammals and birds combined

Jun 11, 2008

Scientists have discovered that there are more bee species than previously thought. In the first global accounting of bee species in over a hundred years, John S. Ascher, a research scientist in the Division of Invertebrate ...

A superorganism in trouble

May 23, 2008

In a time of global warming and catastrophic failure of bee colonies around the world, the new book "The Buzz about Bees" by Juergen Tautz is a timely call for an appreciation of the intricacy of the sociophysiological and ...

Recommended for you

Orb-weaving spiders living in urban areas may be larger

Aug 20, 2014

A common orb-weaving spider may grow larger and have an increased ability to reproduce when living in urban areas, according to a study published August 20, 2014 in the open-access journal PLOS ONE by Eli ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

gmurphy
not rated yet Sep 12, 2009
good work, but evolution doesn't stand still, some mites will survive due to some genetic trait and the whole situation will be back to square one within a few decades
Swarmcatcher
5 / 5 (2) Sep 12, 2009
good work, but evolution doesn't stand still, some mites will survive due to some genetic trait and the whole situation will be back to square one within a few decades

Don't forget that evolution doesn't stand still for the honeybees, either. Mites were thrust on these bee populations over the course of a few years. Researchers have sped up the clock on the evolution of VSH behavior, we didn't teach the bees anything. Future mutations in mite behavior will naturally select for better honeybees. It is the catastrophic environmental changes that merit intervention by researchers.
codesuidae
not rated yet Sep 13, 2009
Will the genetic modifications be patented? How will this bee technology be licensed?