Bee appearance and behavior may be linked, genetic study reveals
Newly discovered genetic knowledge about two pest subspecies of western bees will help commercial and hobby beekeepers.
A new UF/IFAS study has identified genetic traits relevant to the production and behavioral attributes of these two key bee subspecies. For example, researchers found that Cape bees were significantly darker than Africanized bees. This dark coloring could be genetically correlated to their undesirable behavior.
Both subspecies are undesirable in the United States. The first, the “killer bee” or “Africanized bee”, known scientifically as Am scutellata, is a light-colored bee known for its territorial and defensive character. This subspecies was taken from its natural habitat in South Africa to Brazil in the 1950s. There it hybridized with the European bee subspecies kept by Brazilian beekeepers and then moved to the United States.
Am scutellata are considered invasive bees and can invade managed honey bee colonies, which can reduce profits for beekeepers. They are also known for their heightened defensive behavior.
The second subspecies studied, the “Cape bee”, known scientifically as Am capensis, poses a multitude of problems for beekeepers. These bees are more docile but are more likely than African honey bees to take over hives. Cape bees are considered social parasites. Unlike other honey bee subspecies, Cape worker bees can clone themselves, producing female eggs without first mating. These clones can support a hive. These workers cannot reproduce at the same rate as a traditional queen and the colony will eventually shrink and collapse, a phenomenon known as the “calamity capensis”.
“More amazing than the cape worker’s ability to clone itself is how quickly it can take over other colonies,” said UF/IFAS professor Jamie Ellis. “We make sure these bees don’t make it to the United States because in most cases when these bees take over a colony, the colony is doomed.”
Genetic studies can be used to understand “why things are the way they are” for an organism. In this case, the researchers sought to understand what genetic traits contribute to the appearance of these bees and their behavior. Using data collected from South African bees in a previous study funded by the USDA’s Animal and Plant Health Inspection Service in 2013 and 2014, scientists sought to understand which genes are responsible for the physical characteristics of these subspecies.
“We found some really interesting variations in the genes of these bees that may help explain why they look and behave differently,” said UF/IFAS graduate student and co-lead author Laura Patterson Rosa. the study. “There are a lot of implications in what we found. We haven’t yet been able to verify these new findings in other populations, but if our findings stand the test of time, that could explain part of why we see behavioral changes, why they don’t recognize the existence of queens of other subspecies, and why they can clone themselves when other bees cannot.”
“The color phenotype is an important aspect of beekeeping management,” Ellis said. “It can help beekeepers know what type of bee they have.” Cape bees are significantly darker than Africanized bees. This dark coloration could be genetically correlated to their cloning and colony takeover behavior. “There are potentially more than 30 subspecies of honey bees. We only studied two of them in the published study,” Ellis said. “Is this finding true for other dark-colored honey bee subspecies? It would be interesting to look for these mutations in all western honey bee subspecies to determine if this is the case.”
Curiosity about traits, characteristics and color and their impact on behavior continues as researchers hope to use these findings for future research.
Special thanks to the sponsors of this research, including USDA APHIS and the Florida Department of Agriculture and Consumer Services, under the direction of the Honey Bee Technical Council.
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Material provided by University of Florida. Original written by Tory Moore. Note: Content may be edited for style and length.