Nilothauma roquei, 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 : 32-33

Nilothauma roquei sp. n.

( Figs 52–54 )

Type material. Holotype male, BRAZIL: São Paulo: Cananéia, 24º53'03''S, 47º51'22''W, ii.2003, Malaise trap, F. O. Roque ( MZUSP).

Diagnostic characters. The two long, lateral projections of tergite IX overreaching the posterior margin of the tergite and lacking strong setae combined with a rudimentary anal point, curved superior volsella, median volsella with single apical setae, inferior volsella and gonostylus with simple setae, and hind ta2 shorter than hind ta3 will separate the male of N. roquei from all other Nilothauma species.

Etymology. Named after Dr. Fabio O. Roque, who collected the specimen.

Head. AR 0.18. Thirteenth flagellomere 115 µm long; stout subapical seta lost. Temporal setae at least 3 including 2 outer verticals and 1 postorbital. Clypeus with 12 setae. Tentorium and stipes not measurable. Palp segment lengths (in µm): 14, 23, 50, 82, 122. Third palpomere with 2 sensilla clavata subapically, longest 14 µm long. Fifth palpomere / third palpomere 2.45.

Thorax. Dorsocentrals 6 in single row, acrostichals 8, prealars 2. Scutellum with 2 setae.

Wing. Not measurable.

Legs. Spur of foretibia 57 µm long including 29 µm long scale. Midtibia with 1 spur, 32 µm long; hind tibia with 2 spurs, 27 µm and 36 µm long. Combs of midtibia 18 µm long, of hind tibia 18 µm long. Width at apex of foretibia 34 µm, of midtibia 41 µm, of hind tibia 39 µm. Lengths and proportions of legs as in Table 10.

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

Hypopygium ( Figs 52–53 ). Tergite IX with broadly rounded posterior margin; with 11 strong subapical setae; with pair of lateral lobe-like projections sitting high on tergite and extending posterior overreaching posterior margin of tergite, with few weak setae apically, left lobe with strong basal setae. Anal point lacking, but posterior margin of tergite IX with small hump-like structure. Laterosternite IX with 1 seta. Phalapodeme 50 µm long; transverse sternapodeme lacking. Gonocoxite 86 µm long. Inferior volsella 57 µm long, 9 µm wide at base, 9 µm wide at apex, curved in apical 1/3, with rounded apex, with microtrichia and 8 simple setae subapically to apically. Superior volsella ( Fig. 54 ) curved, 36 µm long, 9 µm wide at base, 3 µm wide at apex, with microtrichia. Median volsella ( Fig. 54 ) 9 µm long, tapering, without microtrichia and basal setae, with 1 strong apical setae. Gonostylus 95 µm long, weakly curved, slightly wider in apical 1/2, all setae hair-like. HR 0.90, HV 2.62.

Female and immatures. Unknown.

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

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 507 332 – – – – – – – – – p2 461 295 166 74 64 37 28 0.56 4.54 4. 55 5.1 p3 534 571 267 129 120 83 55 0.47 3.55 4.14 6.5

Figures

FIGURES 52 – 54. Nilothauma roquei sp. n., male. 52 — dorsal aspect of hypopygium. 53 — hypopygium with tergite IX and anal point removed, dorsal view left, ventral view right. 54 — median and superior volsella, dorsal view.