Bees

Geographical race (ecotype) and variation in bee stocks

We recognize considerable genetic diversity in honey bees managed by beekeepers. Bee races, sometimes termed subspecies with a Latinized third formal name designation (for example Apis mellifera mellifera – the German bee), distinguish ecologically, behaviorally, or morphologically different strains or populations of honey bees that have developed, largely due to geographical isolation. These distinct differences are less evident today as we have moved stocks from one location to another and although we might retain the designation of origin, the stock, due to honey bee queens mating with several drones, may in fact have little resemblance to its origins. Over 30 races have been named. The most widespread and useful races for beekeepers in the U.S. are Italian and Carniolan bees. NOTE: Once common, the term race for bees (Italian, Carniolan, etc.) is being replaced by the term “ecotype.”

Worker body color can vary widely within the population of bees in a colony. At one time, ecotypes could be partially defined on the basis of color; for example very dark German bees are distinguished from lighter colored Italian bees. Body size and proboscis (tongue) length have also been used to describe different bees. Behavioral differences might also be used - the African-derived Africanized bee, and the parent native African bee population (Apis mellifera scutellata), are both well known for their defensiveness. Interestingly, the African bee lives alongside other populations of bees that are among some of the gentler bees (such as Apis mellifera monticola).

Light colored worker bee with unusual eyes (cause unknown); photo by Robert Snyder
A darker colored worker bee that is also hairless and shiny (center), likely due to virus infection; photo by The Bee MD collection
 

A malformed bee may be seen on rare occasions in a bee hive. One eyed-workers (cyclops), workers that are small in body size or with small or misshapen eyes or abdomenabdomen:
the segmented, posterior (third) part of the bee body that contains heart, honey, stomach, intestines, Malphigian tubules, reproductive organs, and sting
, and white-eyed workers are genetic mutations that have been noted. Individuals with a mixture of drone and worker characteristics (gynandromorphs) might be seen. Worker bodies with unexpanded wings due to deformed wing virus (DWV) or whose bodies are hairless, blackish colored, and shiny in appearance are also bodies modified by viral infections. When these individiuals are noted they are usually a one-off and should not be of concern.  Note that genetic mutations that result in malformed bodies or body parts  may also occur in drones and queens.

Unusual bee in colony, perhaps a gynandromorph with drone head and worker body features; abdomen appears to be malformed; photo by The BeeMD collection
Worker adult with two mites on thorax and non-expanded wings owing to DWV; photo by The BeeMD Collection
 

Development of new bee stock

There have been heightened efforts to develop bee stocks to improve bee defense against varroa mites. One major effort is development of hygienic bee stock. The USDA imported bees from far eastern Russia, where bees had been exposed to varroa mites for a longer time, and there were no efforts to use chemicals to control the mite, and tested their ability to control mites. Satisfied that they were a better stock, the USDA released the basic stock to a group of Russian bee breeders who continue to maintain this bee line with enhanced mite defensive abilities.

The USDA has developed hygienic bees suitable for commercial beekeepers, the Pol-line. This stock, developed at the USDA Bee Breeding lab in Baton Rouge, LA, has enhanced hygienic qualities. Several commercial bee breeders and more local selected stock bee developers  have used queen mother stock from the lab or from developer John Harbo to rear queens for distribution to beekeepers. Another effort is to devleop a hygienic bee for mite control: the Hilo queen project started with this queen mother stock and has controlled the drone mating opportunities due to location in an area without many beekeepers on the Hilo side of Big Island Hawaii. Unfortunately, due to hieightened policing of brood to control mites that reproduce within capped brood cells, this bee stock is not quite as good for honey production.

Another selection program behavior focuses on bee grooming. A breeding program, originated in 1997 at Purdue University, has developed a stock line of workers that bite the legs from varroa mites, leading to their dehydration or bleeding to death. Stock was tested by several Indiana and Ohio beekeepers and a cooperative of Heartland Bee Breeders has been established to further develop and distribute this stock. This stock has higher numbers of groomers of mites that are on honey bee bodies. The stock is termed mite biters (or simply biters or ankle biters).

Resources

Purdue University. n.d. Our Breeding Program. Purdue University. Accessed 2024. https://extension.entm.purdue.edu/beehive/our-breeding-program/

Meixner MD et. al. 2013. Standard methods for characterising subspecies and ecotypes of Apis mellifera. Journal of Apicultureapiculture:
the science and art of cultivating bees to benefit humans
Research 52(4): 1-28. https://www.tandfonline.com/doi/abs/10.3896/IBRA.1.52.4.05

About bees