Polypedilum (Polypedilum) nudiceps Chaudhuri, Guha and Dasgupta, 1981

Mukherjee, Tuhar, Mukherjee, Bindarika & Hazra, Niladri, 2020, Revision of the Oriental species of Polypedilum Kieffer (Diptera: Chironomidae) with their phylogenetic relationship, Zootaxa 4820 (1), pp. 31-69 : 42-43

Polypedilum (Polypedilum) nudiceps Chaudhuri, Guha and Dasgupta, 1981

Polypedilum (Polypedilum) nudiceps Chaudhuri, Guha and Dasgupta, 1981: 133 .

Material examined. Paratypes 2 males labelled ‘ Polypedilum (Polypedilum) nudiceps Chaudhuri, Guha and Das-gupta, India, West Bengal, Lebong (27.05, 88.27), ix.1978, Coll. P. K. Chaudhuri’; 2 males with larvae and pupae [reared] labelled ‘ Polypedilum (Polypedilum) nudiceps Chaudhuri, Guha and Dasgupta , India, West Bengal, Darjeeling (27.05, 88.25), 23.v.1996, Coll. N. Hazra’; 2 males with larvae and pupae [reared] labelled ‘ Polypedilum (Polypedilum) nudiceps Chaudhuri, Guha and Dasgupta , India, Sikkim, Jorethang (27.09, 88.36), 31.iii.1996, Coll. N. Hazra’; 2 males with larval and pupal exuviae [reared] labelled ‘ India, Sikkim, Gurudongmar Lake (28.00, 88.59), 04.iv.2015, Coll. K. Sanyal’; 3 males labelled ‘ India, West Bengal, Matha (23.11, 86.06), 03. VII.2019, Coll. T. Mukherjee’ .

Remarks. Polypedilum (Polypedilum) nudiceps Chaudhuri, Guha and Dasgupta, 1981 belongs to nubeculosum group due to the presence of horn–like superior volsella with a lateral seta which was overlooked by Chaudhuri et al. (1981). However, Hazra et al. (2003) mentioned the presence of one outer lateral seta on the superior volsella but no illustrative reference was given. The authors had mistakenly captioned the figures 4 and 5 as Polypedilum (Polypedilum) unispinum nom. nov. in the paper of Hazra et al. (2003) instead of Polypedilum (Polypedilum) nudiceps . We observed that the specimens bear an outer seta on the anterior 1/3 of the superior volsella projection and 2–3 basal setae ( Figure 8 ). The outer seta is positioned 0.36–0.4, 0.38 from the apex.

Ecology. During this study the immature stages of Polypedilum (Polypedilum) nudiceps were collected from Himalayan montane streams and Lake Gurudongmar of Sikkim, a part of the eastern Himalaya Biodiversity Hotspot in India. Adult Polypedilum (P.) nudiceps was previously recorded from the eastern Himalayan foothills (Siliguri) to Ghum (2257m), Jorebunglow (2250m), Darjeeling (2010m), Lebong (1820m) and Kurseong (1481m) ( Chaudhuri et al. 1981). Hazra et al. (2003) reared the species after collecting the larvae from different springs and small streams of Jorethang (548m) and Tadong (1524m) of Sikkim, and Lebong and Happy Valley of Darjeeling, West Bengal. It has also been collected from the high altitude streams and Gurudongmar Lake (5226m) where alpine conditions exist. This information is in contrary to Vårdal et al. (2002) as they reported the larvae of Polypedilum occur in all lentic and lotic waters, except at high altitude and latitude. This suggests that the species seems to be eurythermic. Its distribution ranges from foot hill to high altitude> 4000m. The larvae of P. (P.) nudiceps have preference for shallow, slow flowing and standing water of soft organically enriched matters, aquatic plants, leaf axils, soft woods (epixylous), etc.

Figures

FIGURES 8A–B. Adult male of Polypedilum (Polypedilum) nudiceps Chaudhuri, Guha and Dasgupta, 1981. A, Hypopygium; B, Variation of superior volsella. Both to scale: 0.1 mm.