New species of Simulium (Nevermannia) from Korea,with reference to its allied species in the S. vernum species group (Diptera: Simuliidae) in Korea and Japan

The larvae and pupae of a new species, Simulium (Nevermannia) immaculatum sp. nov., are described from Korea. Descriptions are supplemented with photographs of larvae and pupae and habitat information. The new species can be distinguished from other Asian members of the S. vernum group by the cephalic plate and thorax of the pupa devoid of tubercles, 4 pupal gill filaments lying close together, larva with postgenal cleft shorter than postgenal bridge, spot under ocellus absent, and rectal papillae with three simple lobes with single digit‐like small secondary lobule basally.