Abstract
BACKGROUND: The genus Illiesonemoura Baumann, 1975 (Plecoptera, Nemouridae) is a small-sized stonefly with slender and curved embranous cerci. Currently, 18 species of the genus are known worldwide, mainly distributed in the Palaearctic and Oriental Regions, with a total of two species known to China. NEW INFORMATION: Three new species of Illiesonemoura Baumann, 1975, I.bituberculata Wang & Du, sp. nov., I.motuoensis Du & Ji, sp. nov. and I.weii Du & Ji, sp. nov. are described and illustrated, based on male adults from China. Illiesonemourabituberculata is characterised by two pairs of tubercles arising posteromedially from tergum 10 and by two rows of spinules outlining the lateral edge of the ventral sclerite of the epiproct. Illiesonemouramotuoensis is characterised by the heart-shaped epiproct with a thin and slightly sclerotised protrusion between the sclerotised bands. Illiesonemouraweii is characterised by a pair of small knobs on tergum 10, outer lobes of paraprocts basally broad, then slender towards apices with a pointed tip and the epiproct with lateral spinules.