Mating behavior between alien Asian longhorned beetle Anoplophora glabripennis (Coleoptera: Cerambycidae) and a native related species Anoplophora chinensis in Japan

A highly invasive alien species in North America and Europe, the Asian longhorned beetle Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), has been detected in various parts of Japan since 2020. In addition to damaging host trees, A. glabripennis may severely impact the Japanese ecosystem by interfering with A. chinensis (Foster) (formerly called A. malasiaca ), a common and related native species with a similar niche. To assess the potential risk of reproductive interference between the two species, mating behavior between interspecific females and males was examined in the laboratory using field-collected sample individuals. Males of both species mounted on female A. glabripennis and attempted to insert genitalia at similar frequencies (approximately 50%), but A. chinensis males always failed to copulate. In contrast, male A. glabripennis did not have sexual behavior with female A. chinensis . The results show that mating between the two species is typically unsuccessful, although recent research showed that the two species could produce a hybrid when paired for 4 weeks. The erroneous interspecific mating attempts may reduce both species’ fitness. Therefore, the population-level impact of this reproductive interference should be assessed.