Onconeura japi, Wiedenbrug, Sofia, Mendes, Humberto F., Pepinelli, Mateus & Trivinho-Strixino, Susana, 2009

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 : 5-9

Onconeura japi , new species

( Figs 2 A–F, 3 A–G)

Type material. Holotype pharate male, BRAZIL, São Paulo State, Jundiaí, Serra do Japi , Cachoeira Pequena do Paraíso, 23°14´38´´S, 06°57´02´´W, 1058 m a.s.l., 18.xii.2007, S. Wiedenbrug. Paratypes: Allotype female with pupal and larval exuviae, one female with pupal and larval exuviae, 5 pupal exuviae, same data as holotype.

Diagnostic characters. The adult males are separable from other species by the antenna with 10 flagellomeres, low superior volsella and rounded posterior margin of tergite IX without a notch. Adult females are separable by total length, LR1, the shape of the gonapophysis VIII and apodeme lobe. The pupae are separable by having 4 L-setae on segments III–VII, segment VIII with L2 long, reaching lateral corner of anal lobe and fringe longer as twice the length of anal lobus. The larvae can recognized by the median tooth of mentum usually shorter than first lateral teeth and AR 2.33. O. japi tends to be smaller than O. similispina , but no other diagnostic characters were found to separate both species as larva.

Etymology. The species is named after the type locality. The name is to be regarded as a noun in apposition.

Male imago (n=1). Total length 1.75 mm.

Head. AR 0.43. With 10 flagellomeres, ultimate flagellomere 115 µm long, sensilla chaetica not possible to observe. Temporal setae: 1 inner vertical and 2 outer verticals. Clypeus 57 µm long, with 8 setae. Tentorium 122 µm long; 10 µm wide. Palpomeres length (in µm): 22, 25, 35, 50, 90. Third palpomere with at least one sensillum clavatum.

Thorax chaetotaxy. Aps 3, Dc 9, Pa 3, Scts 4.

Legs (n=1). Spur of fore tibia 32 µm long; spur of middle tibia 22 µm long; spurs of hind tibia 32 and 20 µm long. Width of apex of fore tibia 22 µm; of middle tibia 20µm; of hind tibia 30 µm. Legs measurements as in Table 3.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 230 250 190 62 40 22 32 0.76 4.29 2.53 1.67 p2 – 315 180 90 42 25 32 0.57 – – 1.80 p3 230 285 – – 37 21 30 – – – 1.80 Abdomen. Number of setae on tergites I–V 6, TVI 4, TVII– VIII 2; sternites I–II?, SIII-V 1, SVI 2, SVII?, SVIII 2.

Hypopygium ( Figs 2 A, B) Tergite IX with 11 small setae; laterosternite IX with 1 seta. Superior volsella low. Inferior volsella posterior margin concave. Phallapodeme 37 µm long; transverse sternapodeme 27 µm long. Gonocoxite 90 µm long; superior volsella posterior margin straight with the same angle as median margin. Gonostylus 35 µm long; megaseta 8 µm long. HR 2.57, HV 5.00.

Female imago (n=1–2). Total length 1.28 mm.

Wing length 0.67 – 0.75 mm. Wing length/length of profemur 3.08 – 3.11.

Head. AR 0.37 – 0.42. Apical flagellomere 37 – 42 µm long; two sensilla chaetica on flagellomeres 2 – 5. Temporal setae: 1 inner vertical, 2 outer verticals. Clypeus 45 – 55 µm long, with 7 – 13 setae. Tentorium 70 – 75 µm long, 5 – 7 µm wide. Palpomeres length (in µm): 12 – 20, 20, 30 – 35, 47 – 55, 82 – 95. Sensilla clavata 1 – 2 in palp 3.

Thorax chaetotaxy. Aps 2, Dc 7 – 9, Pa 3, Scts 4.

Wing. VR 1.58 – 1.64. Clavus 40 – 45 µm wide; ending 345 – 380 µm from arculus; with 6 – 7 setae. Clavus/ Wing length 0.51.

Legs. Spur of fore tibia 22 – 27 µm long; spur of middle tibia 17 – 20 µm long; spurs of hind tibia 22 – 25 and 25 – 30 µm long. Width of apex of fore tibia 20 µm; of middle tibia 20 – 30 µm; of hind tibia 27 – 32 µm. Legs measurements as in Table 4.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 220–240 212–235 175–187 50–57 30–35 20–22 30 0.80–0.83 4.60–4.67 2.47–2.54 1.67 p2 275–300 270–290 175–177 77–87 37 15–17 25–27 0.61–0.65 4.56–4.68 3.11–3.33 1.29–1.47 p3 230–250 275–285 177–192 100–105 30–32 17 30 0.64–0.67 3.85–3.95 2.79–2.85 1.50–1.76 Abdomen. Number of setae on tergites I 5 – 6, TII– VII 4, TVIII 2. Sternites I not observed, SII– III 2, SIV, V, V I I 1 – 2, SVI 1, SVIII 1 – 4.

Genitalia ( Figs 2 C, F). Gonocoxite with 2 setae. Tergite IX with 6 – 7 setae. Cercus 50 – 52 µm long. Seminal capsules 45 µm long. Notum 47 µm long. Gonapophysis VIII inner margin rounded. Apodeme lobe only slightly curved to anterior and sclerotized medially. Labia basally fused, caudally rounded with a median notch.

Pupa (n=1–4). Total length 1.8–1.9 mm.

Cephalothorax. FS lost. Po 37 – 57 µm and 17 – 30 µm. Longest MAps 75 µm and 45 µm. LAps 27 µm and 40 µm. Pc 1 20 – 30 µm long, Pc2 42 – 77 µm long, Pc 3 17 – 32 µm long. One sensillum near precorneal setae. Dc 1 27 – 50 µm long; Dc 2 30 – 50 µm long; Dc 3 10 – 15 µm long; Dc4 110 – 145 µm long. Distance between Dc1 and Dc 2 20 – 27 µm; Dc2 and Dc3 77 – 132 µm; Dc3 and Dc4 2 – 7 µm. Wing sheath with four to five rows of pearls.

Abdomen ( Figs 3 A, B, C). Tergite I and sternite I without shagreen. Tergite II–III with band of fine shagreen anteriorly, posteriorly with a row of spines. Shagreen on tergites IV–VIII orally with points grouped in small rows, getting sparse posteriorly; shagreen reaches the posterior row of spines on the tergites VII– VIII; posterior row of spines with small points orally. Sternite and parasternites II–VIII with shagreen.

Sternites IV–VII with a row of small spines posteriorly. Sternites VIII on male with a group of spines posteriorly. Sternite VIII on female with shagreen only and low broad posterior projection. Conjunctive TII/III with 2 – 5 hooklets; TIII/IV with 5 hooklets; TIV/V with 5 hooklets; TV/VI with 4 – 5 hooklets; TVI/VII with 3 – 4 hooklets.

O-setae present ventral and dorsal in all segments (not drawn). Segment I with 4 D-setae, 1 L-setae very long, without V-setae. Segment II with 4 D, 4V-setae. Segments III–VII with 5 D, 4V. Segment VIII with 2 D, 1 V. Segments II and VIII with 3 L-setae. Segment III–VII with 4 L-setae. Segment IV with D1-seta 75 – 100 µm long, D5-seta 75 – 117 µm long, L1-seta 22 – 45 µm long, L2-seta 90 – 120 µm long, L3-seta 50 – 95 µm long, L4-seta 17 – 30 µm long. Segment VIII with D4-seta 40 – 77 µm long, D5-seta 55 – 75 µm long, L1-seta 33 – 67 µm long, L2-seta 127 – 167 µm long, L3-seta 52 – 90 µm long

Anal lobe 125-158 µm long ( Fig. 3 C). Anal lobe fringe with lateral 2 – 3 stout and median 17 – 19 taeniate setae; taeniate setae 375 – 460 µm long, one median spur. Anal macrosetae 27 – 120 µm long; median setae 107 – 200, µm long.

Larva (n=1–2). Head. Capsule length 245 µm, width 145 µm. Ventral head length 177 – 183 µm. Ventral length/width 1.14. Labrum with scalloped antero-median margin, SI bifid, SII large, rising from small tubercle, SIII thin between SI and SII ( Fig. 3 D). Brush of premandible not discernible. Mentum as Fig. 3 E. Distance between seta submentalis 42 – 47 µm. Mandible length 60 µm ( Fig. 3 F). Antenna ( Fig. 3 G). AR 2.33. Length of segment I 70 – 72 µm; basal segment width 15 µm; antennal blade 20 µm long; ring organ at 20 – 22 µm from the base of first antennal segment.

Abdomen. Longest abdominal seta, 132 – 158 µm. Procercus 20 µm high and 17 µm wide. Subbasal seta of posterior parapods simple.

Remarks. The larvae were collected from decayed leaves in litter, in a low order stream bellow a waterfall, in the Serra do Japi (Jundiaí, SP) 1058 m a.s.l..

Figures

FIGURE 2. Onconeura japi n. sp. A – B — male, hypopygium, A — detail of tergite IX, dorsal, B — hypopygium, tergite IX removed, sclerites hatched; left: dorsal, right: ventral view with gonostylus removed. C – F — female genitalia, C — ventral view, left with gonapophysis removed, D — dorsal view, E — apodeme lobe, F — labia.

FIGURE 3. Onconeura japi n. sp. A – C — pupa, A — abdomen, dorsal view, B — sternite II, C — sternite VIII and anal lobe. D – G — larva, D — labrum, E — mentum, F — mandible, G — antenna.