Rheocricotopus (Psilocricotopus) okifoveatus Sasa, 1990 Rheocricotopus okifoveatus Sasa, 1990: 129 Rheocricotopus chalybeatus: Sasa & Hasegawa, 1988: 239; Sasa & Suzuki, 2000a: 6, misidentification. Specimens examined: Japan, Ryukyus, Okinawa Pref.: Okinawa Is., Kochinda, 5♂♂, 28. i. 1982 (specimens No. 65:86, 65:95-98); Ryutan Lake, 7. xii. 1981 (specimens No. 65:87-89); Hijagawa, ♂, 11. xii. 1981 (specimen No. 65:85); Hijagawa, ♂, 14. xii. 1981 (specimen No. 65:79); Miyako Is., Tanane, 3♂♂, 2. ii. 1982 (specimens No. 65:34, 99-100); Ishigaki Is., ♂, 2♀♀, 1. ii. 1982 (specimen No. 65:91–93). Rheocricotopus okifoveatus strongly resembles R. chalybeatus in many morphological characters. The former is separable from the latter by having a distinct crista dorsalis on the gonostylus. All the specimens examined have a distinct crista dorsalis. So, we determined them as R. okifoveatus. Although we could not examine the specimens reported from Amami-Oshima Island by Sasa and Suzuki (1993), our own personal materials collected from this area are identified as R. okifoveatus. Hitherto, we have no data that R. chalybeatus is distributed from south of Amami Island. Two slides numbered as 65:91 and 65:92 contain specimens of Smittia pratorum and R. okifoveatus, and Pseudosmittia nisharaensis and R. okifoveatus, respectively.

Published as part of Yamamoto, Nao & Yamamoto, Masaru, 2018, Taxonomic information on some Japanese Chironomidae (Diptera) described by Dr. M. Sasa (†), pp. 516-528 in Zootaxa 4514 (4) on page 518, DOI: 10.11646/zootaxa.4514.4.5, http://zenodo.org/record/2609358