Defensive behavior of the invasive alien hornet Vespa velutina nigrithorax against potential human aggressors

Abstract

In areas where wasps are common, many wasp sting incidents occur. However, guidance on the correct response to wasp attacks remains lacking. In this study, behavioral response experiments were conducted with the aim of minimizing damage from group wasp attacks. The study species was Vespa velutina, which frequently causes wasp sting injuries in the southern regions of South Korea. Results demonstrated that worker wasps showed defensive behavior when a person approached within 3 m of the nest, and the attack rate was higher when the person conducted a large arm swing. When a person walked away after touching a nest, the number of workers attacking did not significantly decrease until they reached 5 m, this reduced to less than half when the person reached 10 m. Approximately 1.3 workers attacked even up to 300 m. However, when the person ran, the number of workers attacking was almost one or less after 10 m. Therefore, it is best to escape quickly to at least 10 m to reduce injury from group attacks. When wasps attacked, even if the person crouched, the attack did not decrease. Our recommended defensive behavior when wasps attack unexpectedly is that victims should turn their face in the opposite direction to the nest or the wasps, protect their face with their hands and arms, lean forward and run away rapidly to minimize injury. Wearing a wide brim hat was very effective, preventing about 75% of stings to the head, so this is also recommended.

The invasive hornet Vespa velutina : distribution, impacts and management options

“…As in the other eusocial wasps, workers of V. velutina tend to defend their colony in case the insects feel threatened, becoming a potential source of danger for people. Defensive behaviours could occur when people approach within three meters from the nest and could last as long as the distance is not increased to a few tens of metres, despite in some cases few hornets could still attack up to 300 m [97]. Defensive behaviours are more frequent towards aggressors dressed in dark colours [98].…”

Host Range Expansion of Nest-Parasitic Moths Pyralis regalis and Hypsopygia mauritialis in Social Wasp Nests: New Findings and Implications for Biological Control

“…Thirty species of social wasps have been recorded in the Republic of Korea [17], including the recently introduced hornet, Vespa velutina nigrithorax (du Buysson, 1905), which is now spreading [18], causing not only sting accidents in rural, forest, and urban areas, but also disrupting honeybees in apiaries, which has a significant economic impact [19][20][21]. Therefore, interest in biological control through natural enemies, as well as physico-chemical control, is increasing [22]; unfortunately, there is limited previous research on these topics.…”