Invasive Hornets Meet Their Match: A Parasitic Showdown

In South Korea, a new player has entered the scene of the invasive hornet, Vespa velutina. This hornet, first spotted in 2003, has been causing trouble for beekeepers, ecosystems, and even human health. Until 2020, no one had found any parasites or parasitoids on these hornets. Then, in Andong City, researchers discovered something surprising: strepsipteran parasites on 11 hornet workers. These tiny invaders included four larvae and seven pupae, with only one individual of undetermined sex. Scientists identified these parasites as Xenos moutoni and X. oxyodontes. This was the first time these parasites were found on V. velutina in invaded regions. These parasites, known as strepsipterans, typically target social wasps. In Korea, V. analis was the only known host until now. The discovery of these parasites on V. velutina shows that native parasites can adapt to new, non-native species. This adaptation is a big deal because it could potentially help control the invasive hornet population. Stylopization, the condition caused by these parasites, is not good news for hornet colonies. Infected workers can't contribute to nest activities, which slows down nest development. Infected reproductive individuals, both males and new queens, can't mate, making it harder for new colonies to form. However, the hornets' high reproductive rate and ability to compensate for losses mean that the parasites' impact might be limited. The discovery of these parasites raises important questions. Can these parasites be used to control the invasive hornet population? Or will the hornets find a way to adapt and overcome this new threat? Only time will tell. One thing is clear: the battle between the invasive hornet and its parasitic foes is far from over.