Nilothauma Kieffer, 1921

Niitsuma, Hiromi, 2016, Two species of Nilothauma Kieffer (Diptera, Chironomidae) from Japan, with description of a new species, Zootaxa 4079 (5), pp. 573-581 : 574

Genus Nilothauma Kieffer

Nilothauma Kieffer, 1921: 270 ; Freeman 1957: 424; Niitsuma 1985: 229; Cranston et al. 1989: 394; Adam & Saether 1999: 5; Mendes & Andersen 2009: 9 .

Kribioxenus Goetghebuer, 1928: 18 [nec Kieffer, 1921: 271]; Edwards 1929: 396, as subgenus of Chironomus ; Townes 1945: 34.

Paranilothauma Soponis, 1987: 11 ; Adam & Saether 2000: 20.

Neelamia Soponis, 1987: 18 .

Tosayusurika Sasa, Suzuki & Sakai, 1998: 52 .

Type species: Nilothauma pictipenne Kieffer by subsequent monotopy.

Remarks. The diagnostic characters of the genus are given by Saether (1977), Cranston et al. (1989), Adam & Saether (1999) and Mendes & Andersen (2009) for the adult; Pinder & Reiss (1986), Adam & Saether (1999) and Mendes & Andersen (2009) for the pupa; and Pinder & Reiss (1983), Adam & Saether (1999), Mendes & Andersen (2009) and Epler et al. (2013) for the larva. No amendment is required to accommodate the new species described here.

Generally the male of the genus differs from those of other Chironomini genera in the foretibia bearing a long spur on the apical scale, one to several dorsal projections on the anal tergite (abdominal tergite IX), and the poorly developed transverse sternapodeme in the hypopygium. The males of some Neotropical species have no dorsal projection on the anal tergite, but these can be recognized by the following features: foretibia bearing a long spur on the conical apical scale, and transverse sternapodeme usually absent or when present without oral projections ( Mendes & Andersen 2009).

The pupa is similar to that of Polypedilum, but recognizable by the abdominal setation. Nilothauma has a pair of LS-seta on abdominal segment IV and a long, taeniate, dorsal seta on the anal lobe. In Polypedilum, all the lateral setae on abdominal segment IV are simple and the dorsal seta on the anal lobe is simple or absent ( Pinder & Reiss 1986, Saether et al. 2010).

The larva resembles that of Paratendipes as the mentum has small median teeth, but differs as the antennae are lacking Lauterborn organs ( Adam & Saether 1999). The larva of Paratendipes has Lauterborn organs on the antennal segments 2 and 3.

Adam & Saether (1999) divided the genus Nilothauma into four species groups, the duminola , babiyi , brayi and pictipenne groups, on the basis of the adult morphology. However, most of the immature forms remain unknown.