Invasive species can spread fast through unprepared ecosystems, taking chaos with them.
The Asian hornet (Vespa velutina) is also one such species. It expands its habitat by more than 80 kilometers (50 miles) a year while preying on honeybees, hoverflies, and other insects.
They came to light almost 20 years ago in Europe. In 2016, they spread into the UK.
“Our research has revealed the remarkable potential for population expansion of eusocial insects in invaded areas, even when original genetic diversity is extremely low,” says University College Cork ecologist Simon Harrison.
University College Cork zoologist Eileen Dillane and team analyzed three genes from the first recorded arrival of the Asian hornet in Ireland in April 2021 and compared them to sequences of wasps found across mainland Europe.
“Earlier work had demonstrated that Asian hornets in Europe apparently shared the same genetic lineage, based on studies of a single gene. We took this a step further and looked at two additional genes which would be more sensitive in detecting variation within the invasive population,” explains Dillane.
“Our results, along with those of other groups, suggest that the entire population of V. velutina in Europe, now potentially numbering many millions of individuals, are descended from a single mated queen arriving from China some 15–20 years ago,” the team writes in their paper.
Asian hornet preys on Asian honeybees that have a complex warning and prey defense system. They’ll surround an attacking wasp in a bee ball, overheating it to death. Unfortunately, European honeybees are an easier target for the wasp.
Asian wasps have a mean sting that some people can have allergic reactions to, they’re not aggressive towards humans, unlike the European wasp.
The very low genetic diversity within the European population of V. velutina could provide a potential for biological control, Dillane and colleagues note.
Unfortunately, the researchers also warn, “climate change is likely to increase the threat of a successful invasion in the future, so vigilance against this species must be maintained.”
Their research was published in the Journal of Hymenoptera.