Colony-level genetics predict gentle behavior in Puerto Rican honey bees

July 06, 2020

BATON ROUGE, LOUISIANA, July 6, 2020--Puerto Rico's population of African-European hybrid honey bees (AHB) are famously known for being much gentler than their continental counterparts. Now Agricultural Research Service (ARS) scientists and their colleagues have found that this reduced defending of the nest is determined by colony-level genetics as opposed to individual bee's DNA, according to a study just published in the Proceedings of the National Academy of Sciences.

The researchers found no significant correlations between individual bees' defensiveness and specific genes. By contrast, they saw strong correlations between a colony's level of defensiveness and how frequently specific genes appeared within the colony.

"It's as if your home environment is a better predictor of how belligerent your temper is than are your individual tendencies in responding to situations. In more scientific terms, for these bees, it is the frequency of the appearance of a gene in the genetic makeup of the colony that is a better predictor than is the genetic makeup of a single bee," explained ARS geneticist Arian Avalos with the Honey Bee Breeding, Genetics, and Physiology Research Unit in Baton Rouge, Louisiana, who led the study.

Defensiveness in honey bees arises from the coordinated actions of colony members, primarily nonreproductive "soldier" bees. Some soldier bees act as guards, patrolling the hive entrance and release alarm pheromones when they encounter an intruder, while other soldiers respond to the alarm by flying out of the hive to sting the intruder. Honey bees die after stinging, so the decision that stinging is called for is a serious one.

"We were also able to winnow down the differences in genetics between aggressive and gentle African-European hybrid honey bees from having to analyze the whole genome to just 256 genes" Avalos said. Honey bees have a total of about 10,000 genes in their genome.

AHB are the descendants of honey bees imported from Africa into Brazil in the 1950s in the hopes of breeding a bee better adapted to the tropics. They instead escaped, interbred with European honey bees (EHB) already present and spread south to Argentina and north into Central America and finally into the United States in only 40 years.

African honey bees, which are a separate sub-species of honey bee distinct from EHB, are best known for their strong, vigorous defense of their nests. In the United States, this behavior has been evident and predominant wherever AHB spread and interbred with EHBs.

AHB arrived to Puerto Rico in 1994 aboard ships carrying cargo like oil pipes from South America and were no gentler than other AHB. However, within a few years of arrival to Puerto Rico, AHB began to show reduced defense of their nests and today are about on par with EHB in this trait. Researchers suspect several factors could have contributed to this process all related to the challenges of surviving in a remote oceanic island with a high density of human population. The process may have also been abetted by major hurricanes such as Irma and Maria, which could have reduced the bees' overall population and genetic diversity.

The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.
-end-


US Department of Agriculture - Agricultural Research Service

Related Bees Articles from Brightsurf:

Two pesticides approved for use in US harmful to bees
A previously banned insecticide, which was approved for agricultural use last year in the United States, is harmful for bees and other beneficial insects that are crucial for agriculture, and a second pesticide in widespread use also harms these insects.

Native bees also facing novel pandemic
There is growing evidence that another ''pandemic'' has been infecting bees around the world for the past two decades, and is spreading: a fungal pathogen known as Nosema.

Bees grooming each other can boost colony immunity
Honeybees that specialise in grooming their nestmates (allogroomers) to ward off pests play a central role in the colony, finds a new UCL and University of Florence study published in Scientific Reports.

Microalgae food for honey bees
A microscopic algae ('microalgae') could provide a complete and sustainably sourced supplemental diet to boost the robustness of managed honey bees, according to research just published by Agricultural Research Service scientists in the journal Apidologie.

Bees point to new evolutionary answers
Evolutionary biology aims to explain how new species arise and evolve to occupy myriad niches -- but it is not a singular or simplistic story.

Quantifying objects: bees recognize that six is more than four
A new study at the University of Cologne proves that insects can perform basic numerical cognition tasks.

Prescribed burns benefit bees
Freshly burned longleaf pine forests have more than double the total number of bees and bee species than similar forests that have not burned in over 50 years, according to new research from North Carolina State University.

Insecticides are becoming more toxic to honey bees
Researchers discover that neonicotinoid seed treatments are driving a dramatic increase in insecticide toxicity in U.S. agricultural landscapes, despite evidence that these treatments have little to no benefit in many crops.

Neonicotinoids: Despite EU moratorium, bees still at risk
Since 2013, a European Union moratorium has restricted the application of three neonicotinoids to crops that attract bees because of the harmful effects they are deemed to have on these insects.

Bees 'surf' atop water
Ever see a bee stuck in a pool? He's surfing to escape.

Read More: Bees News and Bees Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.