SIMULIUM (NEVERMANNIA) BONNINENSE FROM THE OGASAWARA (BONIN) ISLANDS, JAPAN (DIPTERA : SLMULIIDAE) TAXONOMIC ASSIGNMENT TO THE VERNUM-GROUP AND DESCRIPTIONS OF MALE, PUPA AND MATURE LARVA

Descriptions and illustrations of male, pupa and mature larva of a black-fly species, Simulium (Nevermannia) bonninense (Shiraki, 1935), from the Ogasawara (Bonin) Islands in Japan are given for the first time; the female adult is also redescribed. Within the subgenus Nevermannia, this species is assigned to the vernum-group by the combination of the following characters : male genitalia with a lamellate ventral plate without median keel, an elongate style with a large, broad, inwardly-twisted apex, a single parameral hook per side, and an inverted Y-shaped median sclerite; pupal gill with four slender filaments per side; and larval mandible with supernumerary serrations. Interestingly, this species has the katepisternum haired in both sexes of adults, female genital fork with a prominent projection directed forwards on each arm, and pupal frons with two trichomes on each side, all of which are rare in this species-group. Brief notes on adult blood-feeding, and larval habitats of S. (N.) bonninense are given.