Africanized bees – which possess genes from both European and African honeybees – first arrived in California in the 1990s. Today, as many as 65 percent of wild honeybees in Southern California have a mix of European and African genes, says a recent study. And they keep moving north: the first bees with African DNA have almost reached California’s capital Sacramento claim the study authors.
The increasing dominance of African bee genes is bad news for the people living the affected states, such as California, Texas and Arizona, but it is good news for bee scientists.
The bad news first: Africanized bees, also called killer bees, are highly aggressive. People have been seriously injured or killed after thousands of stings from Africanized bees which are quick to defend their hives.
The good news is: Africanized bees have many desirable qualities, such as resistance to some of the diseases and parasites that are resulting in higher colony losses of their US relatives of European descent.
Robust health and gentle disposition
US beekeepers prefer European honeybees because they are easier to manage. But there may be a way for beekeepers to get the disease resistance they're looking for in European bees while minimizing the risk that Africanized bees pose, says study author Joshua R. Kohn: "By dissecting the genomes of Africanized honey bees to find regions responsible for advantageous traits, we may be able to combat recent declines in managed honey bee populations that are so critical for food production." Disease-resistant bees with a gentle disposition could be a win-win proposition for everyone.
The journey of the Africanized bee
The story of killer bees in the Americas started in the 1950s. In an effort to breed honeybees better suited to South America's tropical climate, a biologist in Brazil imported a subspecies (Apis mellifera scutellata) from southern Africa to interbreed with bees from Europe.
Some of them escaped and bred with local populations of European honeybees, and their hybrid descendants spread at a speed of 500 kilometers annually. However, their ability to set up permanent colonies in the north seems to be limited by cold temperatures during the winter months, said study author Kohn. However, higher temperatures caused by global warming could mean that killer bees may continue to push north in the coming years, he added.
The study titled Range and Frequency of Africanized Honey Bees in California (USA) by Yoshiaki Kono and Joshua R. Kohn was published in the scientific online journal PLOS ONE.
It was picked up by several online media, among them www.livescience.com and www.natureworldnews.com.