Onconeura

Wiedenbrug, Sofia, Mendes, Humberto F., Pepinelli, Mateus & Trivinho-Strixino, Susana, 2009, Review of the genus Onconeura Andersen et Saether (Diptera: Chironomidae), with the description of four new species from Brazil, Zootaxa 2265, pp. 1-26 : 21-22

Onconeura sp. “taquara”

( Figs 9 C–F)

Thienemanniella semifimbriata -Gruppe spec. 2: Wiedenbrug 2000: 94.

Material examined. 6 pupal exuviae. BRAZIL, Rio de Grande do Sul State, Taquara, Waterfall about 8 km from Taquara near the road in direction to Arroio Grande, 150 m a.s.l., drift, 14.xi.1994, Fittkau and Wiedenbrug.

Diagnostic characters. The pupae are separable from other species by the fringe with few non- taeniate setae, shorter than the length of anal lobe, shagreen on TII–TIV distributed anteriorly, separate from caudal spine rows. Spines of caudal row on TIV about as long as wide and L2 -seta at least as long as half segment length.

Pupa (n=1 – 2). Total length 1.7 – 1.8 mm.

Cephalothorax ( Fig. 9 C, D). FS 100 µm long. Longest Po 45 µm; Longest MAps 45 µm and 88 µm. LAps 12 µm. 3 Precorneal setae Pc3 28 µm long. One sensillum near precorneal setae. Dc1 48 µm long; Dc2 30 µm long; Dc3 10 µm long; Dc4 70 µm long. Distance between Dc1 and Dc2 25 µm; Dc2 and Dc3 108 µm; Dc3 and Dc4 23 µm. Wing sheath with at least three rows of pearls.

Abdomen ( Fig.9 E). Tergite I and sternite I without shagreen. Tergite II–VIII with shagreen anteriorly and with posterior row of spines followed anteriorly by smaller spinules. Spines of posterior row on TIV as long as wide ( Fig. 9 F). Sternite and parasternite II with very fine shagreen. Sternites III–VIII with fine shagreen, shagreen extending to parasternites. Sternites V–VII with 1 – 2 rows of small spinules. Sternite VIII with a posterior field of coarse shagreen. Sternite VIII on female with shagreen only and low broad posterior projection. Conjunctive TII/III with 6 – 8 hooklets; TIII/IV with 9 – 10 hooklets; TIV/V with 8 – 9 hooklets; TV/ VI with 8 – 9 hooklets; TVI/VII with 7 hooklets.

O-setae present ventral and dorsal in all segments (not drawn). Segment I with 4 D-setae, 1 L-setae, without V-setae. Segment II with 4D, 4V and 3L-setae. Segments III–VII with 5 D, 4V and 4 L-setae, L4 very tiny or just as a pit. Segment VIII with 2 D, 1 V and 3 L-setae. Segment IV with D1-seta 40 – 48 µm long, D5- seta 58 – 60 µm long, L1-seta 13 – 15 µm long, L2-seta 75 µm long and thick, L3-seta 15 – 23 µm long. L4-seta 7 µm long. Segment VIII with D4-seta 30 – 63 µm long, D5-seta 95 – 125 µm long, L1-seta 10 – 15 µm long, L2-seta 90 µm long, L3-seta 23 – 25 µm long.

Anal lobe 135 – 140 µm long. Anal lobe fringe with lateral 1 – 2 stout and shorter setae and 8 – 9 longer nontaeniate setae 78 – 83 µm long, one median spur long, triangular. One anal macrosetae; median setae 137 – 165, µm long.

Remarks. The pupal exuviae were collected as drift from a shady pool after a small waterfall of about 50 cm, in northeastern Rio Grande do Sul State.

Figures

FIGURE 9. Onconeura sp. “ hat ” A – B pupa and Onconeura sp. “ taquara ” C – F pupa. A - cephalothorax. C — frontal apotome. D — thorax. B, E — abdomen, dorsal view. F — detail of posterior row of spines on tergite IV.