The expansion of the Asian hornet may slow – Le Figaro

A inbreeding phenomenon that disrupts the development of colonies was highlighted by a research team from the Institute researchers on the biology of the insect of the François Rabelais University of Tours ( IRBI).

The Asian hornet was reported for the first time in the Lot-et-Garonne in 2004. Since it keeps s’ spread in France but also in Europe. 67 departments are affected as well as Spain, Portugal, Italy, Belgium and Germany. They all come from a single female transported in a pot imported from China by a producer of bonsai. It is a study of 170 hornets, 83 in France and 87 captured in the original insect in China area which concluded that this female would be from a region located between the provinces of Zhejiang and Jiangsu, in eastern China.

Loss of genetic diversity

Since 2004 expansion seems irresistible. Yet a recent study by Research Institute researchers on the biology of the insect (IRBI) from the University of Tours provides for the expansion of the Asian hornet should soon slow down. According to scientists, the Asian hornets suffer from a phenomenon of “inbreeding depression” due to low number of queens that have enabled their installation in France. In a statement, the scientists explain that “as for the colonies of wasps and hornets European, those of Asian hornet pass through two stages during the year, from spring to mid-August, workers are produced and enlarge the nest and end August-December breeding appear (males and future queens). ”

Now “68% of the analyzed colonies produce males during the first period when only the workers should be present.” Genetic analysis has shown that their production was linked to a loss of genetic diversity in this species. As males do not participate in activities within the colony, this could slow down and “term limit expansion of this invasive species.”

A less toxic venom than its European cousin

The expansion of the Asian hornet has caused problems several orders in the territories it has affected. Since 2009, four deaths were recorded after the insect bites. The last was a 60 year old man in Britain this summer. He died after being stung on the forehead and neck. Bites would have caused cardiac arrest. Asian hornets represent the real danger because they often settle in residential areas and when they feel attacked, they used to attack en masse. But bites are rare and the venom of the Asian hornet is less toxic than its European cousin.

The Asian hornet poses economic problems since they tend to attack the apiaries. It would also pose environmental problems as it is a generalist predator that may have an impact on biodiversity.