Nilothauma anamariae, Dantas & Hamada, 2017

Dantas, Galileu P. S. & Hamada, Neusa, 2017, Three new species of Nilothauma Kieffer (Diptera: Chironomidae) from Brazil, Zootaxa 4282 (2), pp. 350-360 : 352-354

Nilothauma anamariae sp. nov.

( Figs. 9–14 )

Type material. Holotype: male, BRAZIL: Rio Grande do Sul, Bossoroca, Barra do Angico, Rio Piratinim , 28°32'05.53" S 54°57'30.05" W, 29–30.ii.2014, light-trap, A. M. Pes ( INPA) . Paratype: 1 male, as holotype (INPA).

Diagnostic characters. Anal point well-developed; TIX without dorsal projections, without dorsal setae in the median area; inferior volsella L-shaped, with a long simple lateral bristle, strongly curved and an apical lobe directed inwards bearing 10–12 apically split setae.

Etymology. The name is in honor of Dr. Ana Maria Oliveira Pes, who collected the type specimens

Male (n= 1–2). Total length 2.28–2.50 mm. Wing length 1.14–1.15 mm. Total length / wing length 1.98–2.20. Wing length / length of profemur 2.10–2.15.

Coloration. Head and abdomen greenish-yellow, wings unmarked, antenna, vittae, postnotum and inferior half of preepisternum light-brown.

Head ( Fig. 9 ). Antenna as in Figure 11 . AR 0.21–0.24. Thirteenth flagellomere 117–125 µm long. Temporal setae 5 in a single row. Frontal tubercles not distinct. Clypeus with 18–19 setae. Cibarial pump with anterior margin slightly concave, 140–154 µm long. Tentorium 90–92 µm long, maximum width 16 µm. Stipes 116 µm long. Palp segment lengths (I–V, in µm): 17–19, 25–27, 56–65, 76–77, 100–131. Third palpomere with 2 sensilla clavata subapically, longest 16–18 µm long. Fifth palpomere / third palpomere 1.80–2.02. Eyes separated by 32–34 µm, dorsomedial extension 101–115 µm long, 74–87 µm wide.

Thorax ( Fig. 10 ). Dorsocentrals 8–10 in single row; acrostichals 16–18, biserial, starting close to anterior margin of scutum; prealars 3. Scutellum with 2 setae.

Wing ( Fig. 12 ). WW 0.40–0.41. VR 1.41–1.54. Brachiolum with 2 setae, R with 10–11 setae, R1 with 8–11 setae, R4+5 with 9–15 setae, remaining veins bare. Anal lobe reduced.

Legs. Spur of fore tibia 20 µm long, scale 21 µm long. Mid tibia with 1 spur, 20 µm long; hind tibia with 1 spurs, 25 µm long. Combs of mid tibia 18–20 µm long, of hind tibia 17–18 µm long. Width at apex of fore tibia 41–42 µm, of mid tibia 44–46 µm, of hind tibia 47–51 µm. Mid and hind legs with pseudopurs in ta1–ta4; all legs with slender and curved claws. Lengths (in µm) and proportions of leg segments presented in Table 2.

Abdomen. Tergites with few setae. Segment VIII 132–141 µm long, 170–177 µm wide, weakly tapered anteriorly.

Hypopygium ( Figs 13–14 ). Tergite IX with posterior margin wedge-shaped; without dorsal lobe(s), without dorsal setae in the median area, with 7–8 setae on each side close to base of anal point, distinct anal tergite bands present. Anal point well-developed, rounded at apex, 47–56 µm long, 15–16 µm wide medially. Laterosternite IX with 3 setae. Phallapodeme straight, 63–73 µm long; transverse sternapodeme straight, 38–39 µm long. Gonocoxite 90–93 µm long. Inferior volsella robust, curved at apex, 65–72 µm long, with a long simple and curved lateral bristle, strongly curved and an apical lobe directed inwards bearing 10–12 apically split setae. Superior volsella, 40–45 µm long, cylindrical and straight, with blunted apex, covered with microtrichia, without setae. Median volsella short, 9–11 µm long, straight, with 2 apical setae sitting on tubercles. Gonostylus tapered, 101 µm long, with 2 dorsal setae near the base. HR 0.89. HV 2.47.

Female imago and immatures. Unknown.

Distribution. Known only from the type locality in Rio Grande do Sul State, Brazil.

Figures

FIGURES 9 – 12. Nilothauma anamariae sp. nov. (Diptera: Chironomidae). 9 — Head. 10 — Thorax. 11 — Antenna. 12 — Wing.

FIGURES 13 – 14. Nilothauma anamariae sp. nov. (Diptera: Chironomidae). 13 — Hypopygium in dorsal view. 14 — Hypopygium in dorsal view, with tergite IX removed.