Nilothauma

Mendes, Humberto Fonseca & Andersen, Trond, 2009, Neotropical Nilothauma Kieffer, 1921, with the description of thirteen new species (Diptera: Chironomidae), Zootaxa 2063, pp. 1-45 : 38-40

Nilothauma sp. 1 (Pupa)

( Figs 75–79 )

Material examined. BRAZIL: Mato Grosso: Serra dos Parecis, Pensão Alemã, 2 pupal exuviae, 10–11.x.1965, drift net, E. J. Fittkau ( ZSM).

Diagnostic characters. The pupa can be separated from other known Neotropical pupae by having a thoracic horn with 5 branches and anterior and posterior shagreen patches on tergites VII–VIII connected by a narrow band of fine shagreen.

Pupa (n = 1–2). Total length 3.40–3.47 mm. Exuviae light brown.

Cephalothorax ( Fig. 75 ). Frontal apotome ( Fig. 76 ) wrinkled, frontal setae 73–94 µm long. Thoracic horn ( Fig. 77 ) with 5 filaments, main filament 320 µm long, with few weak spines; basal ring oval, 7–9 µm of diameter. Scutum with field of few weak tubercles. Antepronotals apparently 2, median about 50 µm long, lateral 14 µm long. Precorneals 2, subequal, about 15 µm long. Dorsocentrals 4, Dc 1 7–12 µm long, Dc 2 27–61 µm long, Dc 3 16–36 µm long, Dc 4 7–11 µm long; Dc 1 11–48 µm in front of Dc2, Dc2 100–141 µm in front of Dc3, Dc3 11 µm in front of Dc4.

Abdomen ( Figs 78–79 ). Tergite I bare; tergites II–VI with transverse anterior band of somewhat stronger spinules, merging with median field of finer shagreen; anterior band of shagreen on tergite VI separated from posterior shagreen patch; tergite VII with anterior and posterior shagreen patches connected by narrow band of fine shagreen; tergite VIII with weak anterior shagreen patches and median and posterior shagreen patches connected by narrow band of fine shagreen; tergite IX bare. Tergite II with 200–204 µm long row of 43–46 hooks, each hook 4–9 µm long. Conjunctives III/IV and IV/V with 4–5 rows of spinules. Pedes spurii B weakly developed on segment II. Anal comb 25 µm long, consisting of 1–4 spurs.

Abdominal setation. Lateral setae on segments I–VIII as: 0, 3, 3, 3–4, 4, 4, 4, 4; posterior lateral seta on tergite IV and all lateral setae on tergites V–VIII taeniate, remaining setae hair-like. All tergites with 1 pair of O setae.

Anal lobe. With complete fringe of 28–31 taeniae on each side, longest 450–500 µm long. Male genital sac overreaches anal lobe by 225–236 µm.

Distribution. Only known from two pupal skins from Mato Grosso, Brazil.

Figures

FIGURES 75 – 79. Nilothauma sp. 1, pupa. 75 – thorax, lateral view. 76 – frontal apotome. 77 – thoracic horn. 78 – tergites I – VII. 79 – tergite VIII and anal lobe.