Asian hornet: inbreeding could slow its expansion – Why doctor?

Asian hornets were introduced in France there are about ten years. However, their expansion could be slowed down now.

It is in the pottery came from China that the Asian hornet was transported and accidentally introduced in France in 2004. Since A dozen deaths were attributed to its bites, and in 2012 the insect was appointed as a health hazard second category.

However, this species is evolving. Scientists at the Research Institute of Insect Biology, University of Tour showed an alteration of the structure of colonies of hornets.

The life cycle of the Asian hornet is in two stages: in the spring and until late August, are born of the workers of the colony, while in autumn and winter, it is the breeders that appear, that is to say males and future queens. But this well-regulated organization would be disturbed now.

More males disrupt the organization

The Institute’s researchers collected several colonies of Asian hornets between 2012 and 2014, they observed the reproductive cycle. According to them, 68% of the analyzed colonies produce males during the first period of the cycle, instead of workers. Now these males do not participate, like the workers, the expansion activities of the colony, and eat the food, to the detriment of the larvae.

Another problem for the Hornets, it is possible that these males born instead of the workers are sterile, according to Eric Darrouzet, who coordinated the work. Finally, fewer queens were produced during the breeding season. All this can hinder the smooth development of the colony.

The male birth to an unusual period can be explained, according to the scientists, by low genetic diversity with the fact that few individuals and especially little queens were introduced in France in 2004. The Asian hornets are actually affected by inbreeding problems.

Different possible scenarios

Eric Darrouzet explains that several possible scenarios for the evolution of this species. Expansion could be decreased by such changes in the structure of the colonies. Nevertheless, hornets could also adapt to these changes and the disappearance of certain individuals, for example by increasing the number of couplings.

If a slowdown was observed, this would be good news in Since the expansion of hornets has a health impact, very negative economic and environmental. Large predator of bees, the Asian hornets affect biodiversity by addressing these, and are the bane of beekeepers.

As for the men, the scientists explain that deaths are rare, although piquûre is painful. Only people who have allergies really are at risk, the problem being that it is very difficult to know if we will develop an allergy or not.