About Polistes japonicus de Saussure, 1858
Description and identification: Polistes japonicus de Saussure, 1858 has a pronotum with sparse, minor punctures. In males, the anterior margin of the clypeus is rounded. The scutellum disc is slightly convex. The abdomen is yellow with brown and/or black bands. The wings are darkened with a brownish tint. There are no morphological differences between workers and new reproductive females of this species. P. japonicus shows sexual dimorphism, with males larger than females; this difference is suggested to result from local mate competition between males.
Distribution and habitat: While the first described population of P. japonicus was found in Japan (the specific epithet japonicus means "of Japan"), these wasps are actually rare in Japan, where research on the species has taken place in central Japan. They have also been recorded in Vietnam, India, China, Mongolia, and Korea.
