About Vespa simillima Smith, 1868
Vespa simillima Smith, 1868, commonly called the yellow hornet, is a widespread common hornet species native to the Eastern Hemisphere. This species includes a well-known color form that is referred to as the Japanese hornet or Japanese yellow hornet (known in Japanese as キイロスズメバチ). The species also has a typical mainland color form, called ケブカスズメバチ in Japanese and 털보말벌 ("hairy wasp") in Korean. This mainland color form is darker and hairier than the yellow Japanese color form. The mainland form inhabits Hokkaido, the Korean Peninsula, Eastern Siberia, and China, and is less common in Japan, where the yellow color form is the dominant variant. Vespa simillima should not be confused with the Asian giant hornet (Vespa mandarinia), which has a color form sometimes called the "Japanese giant hornet". Although many hornet species were historically split into multiple recognized subspecies, the most recent taxonomic revision of the genus Vespa classifies all previously recognized subspecific names as synonyms. This change reduces these former subspecies names to nothing more than informal labels for regional color forms of the species.
