Nilotanypus pusillus, Andersen & Pinho, 2019

Andersen, Trond & Pinho, Luiz C., 2019, Two new species of Nilotanypus Kieffer, 1923 (Diptera, Chironomidae, Tanypodinae) from Brazil, Norwegian Journal of Entomology 66, pp. 11-18 : 12-13

Nilotanypus pusillus n. sp. ( Figures 1 , 3 & 4 )

Type material: Holotype male: Mato Grosso State, Nova Xavantina, Fazenda Sr. Queté, Córrego Cachoeira , 254 m a.s.l., 14 o 32.817’S 51 o 31.395’W, 16.x.2007, light trap, leg. L.C. Pinho et al. ( MZUSP).

Etymology: From latin pusillus , meaning very little and referring to the small size of the species.

Diagnostic characters: The combination of a wing length of 0.81 mm, pseudospurs on mid ta 1 – ta 3, an antennal ratio of 0.45, and the color pattern of the abdomen, with tergites I–V light brown and tergites VI–IX and hypopygium brown, will separate the species from all other species in the genus.

Description: Male (n = 1). Total length 1.51 mm. Wing length 0.81 mm. Total length / wing length 1.86. Wing length / length of profemur 2.77.

Coloration. Head, antenna and thorax brown; abdominal tergites I–V light brown, tergites VI– IX and hypopygium brown; legs light brown;

wing membrane pale brown.

Antenna. Antennal ratio (AR) = 0.45. Ultimate flagellomeres 168 µm long, apical seta missing.

Head. Temporal setae 9, including 2 strong frontals, 2 inner verticals, 3 outer verticals and 2 postorbitals. Clypeus with 16 setae. Tentorium 91 µm long, 17 µm wide. Palp segment lengths (in µm): 21, 25, 62, 92, 144. Third palpomere with 2 sensilla along inner margin, longest 14 µm long.

Thorax. Antepronotals 4; dorsocentrals 22, starting close to antepronotum, irregularly biserial in front; acrostichals 20, starting close to antepronotum, biserial in front; prealars 8 in two groups, anterior group with 3 setae, posterior group with 5 setae; supraalar 1; prescutellum with 1 strong seta; anterior border of mesonotum with row of 9 tubercles. Scutellum with 7 strong setae, uniserial and about 14 weak, scattered, anterior setae.

Wing ( Figure 1 ). Venarum ratio (VR) = 0.70. Wing membrane and veins densely covered with setae. Brachiolum with 2 setae. Squama with 13 setae.

Legs. Width at apex of fore tibia 21 µm, of mid tibia 26 µm, of hind tibia 28 µm. Spur of fore tibia 30 µm long, of mid tibia 39 µm long, of hind tibia 43 µm long. Fore tarsus apparently without pseudospurs; pseudospur of mid ta 1 33 µm long, of mid ta 2 26 µm long, of mid ta 3 18 µm long; hind tarsus missing. Comb of hind tibia with 7 setae, longest seta 35 µm long, shortest 28 µm long. Length (in µm) and proportion of legs as in Table 1.

Hypopygium ( Figures 3–4 ). Tergite IX with slightly concave posterior margin and 2–3 setae on each side. Anal point broadly rounded. Gonocoxite 69 µm long, 37 µm wide. Gonostylus 46 µm long, megaseta 7 µm long. Hypopygium ratio (HR) = 1.50. Hypopygium value (HV) = 3.28.

Norwegian Journal of Entomology 66, 11–18 (2019)

Female and immatures. Unknown. Distribution. Only known from the type locality in Mato Grosso State, Brazil .

Figures

FIGURE 1-2. 1. Nilotanypus pusillus n. sp. male, wing. 2. Nilotanypus urubici n. sp. male, wing. (Photo Hege Avsnes Dale).

FIGURES 3–6. 3. Nilotanypus pusillus n. sp. male, hypopygium, dorsal view. 4. Nilotanypus pusillus n. sp., left side of hypopygium, showing the apodemes. 5. Nilotanypus urubici n. sp. male, hypopygium, dorsal view. 6. Nilotanypus urubici n. sp., left side of hypopygium, showing the apodemes.