Nilothauma fazzariense, Mendes, Humberto Fonseca & Andersen, Trond, 2009

Mendes, Humberto Fonseca & Andersen, Trond, 2009, Neotropical Nilothauma Kieffer, 1921, with the description of thirteen new species (Diptera: Chironomidae), Zootaxa 2063, pp. 1-45 : 21-22

Nilothauma fazzariense sp. n.

( Figs 24–26 )

Type material. Holotype male, BRAZIL: São Paulo: São Carlos, Córrego do Fazzari, 21º57'07''S, 47º50'12''W, 17.iv–25.iv.2004, Malaise trap, F. O. Roque ( MZUSP).

Diagnostic characters. The two dorsal, setose lobes on tergite IX and presence of a lateral thorn on laterosternite IX combined with a barely indicated anal point, pediform superior volsella apparently fused with median volsella, inferior volsella and gonostylus with simple setae, and hind ta2 and ta3 of about same length will separate the male of N. fazzariense from all other Nilothauma species.

Etymology. Named after Córrego do Fazzari.

Male (n = 1). Total length 2.59 mm. Wing length 1.33 mm. Total length / wing length 1.95. Wing length / length of profemur 2.15.

Coloration. Thorax uniformly pale brown; legs and antenna yellowish brown.

Head. AR 0.21. Thirteenth flagellomere 148 µm long; stout subapical setae 58 µm long. Temporal setae 5 in single row including 1 inner vertical, 3 outer verticals, and 1 postorbital. Frontal tubercles well developed. Clypeus with 14 setae. Tentorium and stipes not measurable. Palp segment lengths (in µm): 20, 68, 93, 93, 125. Third palpomere with 2 sensilla clavata subapically, longest 18 µm long. Fifth palpomere / third palpomere 1.34.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 617 368 562 368 286 212 83 1.52 1.63 1.75 – p2 599 562 322 157 147 92 64 0.57 3.22 3.60 – p3 617 580 332 166 166 92 64 0.57 3.13 3.61 7.0

Thorax. Dorsocentrals 7 in single row, acrostichals 5, prealars 2. Scutellum with 2 setae.

Wing. VR 1.42. Brachiolum with 1 seta, R with 9 setae, R4+5 with 2 setae apically, remaining veins bare.

Legs. Spur of foretibia 70 µm long including 27 µm long scale. Midtibia with 1 spur, 48 µm long; hind tibia with 2 spurs, 29 µm and 50 µm long. Combs of midtibia 22 µm long, of hind tibia 23 µm long. Width at apex of foretibia 36 µm, of midtibia 39 µm, of hind tibia 40 µm. Lengths and proportions of legs as in Table 5.

Abdomen. Tergites with few setae. Segment VIII long, weakly triangular, tapering anteriorly.

Hypopygium ( Figs 24–25 ). Tergite IX with broadly rounded posterior margin; with 7 strong subapical setae; with pair of dorsal, anteriolateral lobes, each with 5 long setae. Anal point proper absent, but posterior margin of tergite IX with small hump-like structure. Laterosternite IX with 1 seta and lateral thorn. Phalapodeme 54 µm long; transverse sternapodeme lacking. Gonocoxite 86 µm long. Inferior volsella 50 µm long, 10 µm wide subapically, curved with broadly rounded apex, with microtrichia and 8 short, simple setae subapically to apically. Superior volsella ( Fig. 26 ) pediform with broadly rounded apex, 25 µm long, 14 µm wide at base, 8 µm wide subapically, densely covered with microtrichia. Median volsella completely fused with superior volsella, apparently consisting of 3 strong setae on small tubercles on inner margin of superior volsella. Gonostylus nearly parallel-sided, weakly curved, 81 µm long, all setae hair-like. HR 1.05, HV 3.19.

Female and immatures. Unknown.

Distribution. Known only from the type locality in São Paulo, Brazil.

Figures

FIGURES 24 – 26. Nilothauma fazzariense sp. n., male. 24 — dorsal aspect of hypopygium. 25 — hypopygium with tergite IX and anal point removed, dorsal view left, ventral view right. 26 — median and superior volsella, dorsal view.