Animal Behaviour: Confused hornets may attack humans

August 7, 2003

A common ingredient of cosmetics and fragrance can throw hornets into a defensive rage, according to a Brief Communication in the August 7, 2003 Nature. The insects release similar chemicals when they are threatened, so it is possible that humans might inadvertently provoke confused hornets into attacking them. Masato Ono and colleagues identified a multi-component alarm pheromone in the venom of the world’s largest hornet, Vespa mandarinia. One of the ingredients of this chemical cocktail elicits a strong attack reaction by fellow hornets, the team found. Worker insects exposed to the extract flew excitedly around the nest and rushed towards the target. Up to 74 people die each year in Japan after being stung by insects. Hornets are among the worst offenders. The team went on to analyse the volatile components in venom from all seven Japanese hornet species. The samples contained chemicals that are common in manufactured food as well as cosmetic products. It may be sensible to screen these products for the presence of pheromones that could alarm dangerous insects, the team advise.

“Insect signalling: Components of giant hornet alarm pheromone,” Masato Ono, Hirokazu Terabe, Hiroshi Hori, Masami Sasaki, Nature, August 7, 2003

Abstract © 2003 Nature

Masato Ono, Centre of Excellence Integrative Human Science Program, Research Institute and Graduate School of Agriculture, Machida, Tokyo