The Japanese hornet Vespa simillima Smith, an important nuisance pest in urban areas (Hymenoptera:Vespidae)

Abstract

Taxonomy, life history, nest architecture, and nesting habits of Vespa simillima Smith are given. It is one of the most common vespines in Japan and a nuisance pest in residential and urban areas. The species consists of two subspecies, V. s. simillima Smith and V. s. xanthoptera Cameron. In Hokkaido, northern Japan, V. s. simillima colonies last for ca. 4.5 months, i. e., from late May to early October, and mature nests have mean values of 1,821 cells, 6.6 combs and 315 adults. Colony size was considerably smaller than in xanthoptera (southern subspecies), probably because of the short colonial duration in the subspecies simillima. Preferred nest sites differed between the subspecies as well as among habitats. Structural nests were very frequent in urban areas : ca. 50% of a total of 600 nests destroyed in Otaru, Hokkaido, between 1974 and 1980 were built in wall voids of buildings (subsp. simillima), and ca. 70% of 150 nests destroyed in Kyoto, southwestern Honshu in 1978 were in attics (subsp. xanthoptera). In Otaru, ca. 70% of the people injured by the hornet were stung by wasps nesting in wall voids of buildings. Control techniques are given with examples adopted by the Otaru Public Health Centre.