Paratanytarsus silentii, Trivinho-Strixino, Susana, 2010

Trivinho-Strixino, Susana, 2010, Two new species of Paratanytarsus (Diptera: Chironomidae) from southeast of Brazil, Zootaxa 2726, pp. 59-67 : 65-66

Paratanytarsus silentii , sp. n.

( Fig. 19 )

Type material. Holotype male, Brazil: São Paulo State, São Paulo, Córrego do Silêncio, Parque Estadual do Jaraguá (23°24’ S e 45°44’ W), leg. F. O. Roque, 03/VIII/2000. Paratype: 1 male same data as holotype.

Etymology. From Latin silentii , refers to the name of the stream (Córrego do Silêncio) where the specimens were collected.

Diagnosis. Adult male: wing membrane transparent, covered with setae; AR 1.22; LR 2.58–2.77; hypopygium with anal tergite bands separated; anal point long, without anal crests; superior volsella quadrangular, digitus very long, extending well beyond posteromedian corner of superior volsella; median volsella slender and very long (58 µm), with several spatulate lamellae distally.

Description. Male (n = 2). Dimensions. Small, length c. 3.30 mm. Wing length 1415–1562 µm.

Coloration. Head pale yellowish green, flagellum and maxillary palp yellowish. Thorax green yellowish. Wing membrane transparent and veins pale. Abdomen yellowish. Legs pale.

Head. Eyes ratio 1.27–1.54. Antenna with 13 flagellomeres; flagellum 906 µm long; AR 1.22. Palpomeres 1–5 length: 25, 31–50,125–156, 187–221 µm. Frontal tubercles short, 6 µm long (1). Temporal setae 8–9. Clypeus with 12–14 setae.

Thorax. Acrostichals 15, biserial beginning near antepronotum; dorsocentrals 8, uniserial; prealar 1; scutellars 6.

Wing. 418 µm wide; C ending close to R4+5, before wing apex; R4+5 ending slightly distally to apex of M 3+4; R2+3 indistinct. Membrane covered with setae, becoming dense in distal ½ part. Setae present on all veins except M and RM; brachiolum with 1 seta; squama bare. RM proximal to FCu, VR 1.16–1.26.

Legs. Fore tibia with short white spur 17–20 µm long. Mid and hind tibiae with black combs; each tibia with only one spur. Lengths (in µm) and proportions as table 4.

fe ti ta1 ta2 ta3 ta4 ta5 LR

p1 625–787 363–388 1000–1006 525–550 381–387 287–281 106–131 2.58–2.77 p2 756–781 556–562 356–369 187–194 119–131 81 50–62 0.63–0.66 p3 794–800 669–681 500–512 312–319 219–237 137–144 62–81 0.73–0.76 Hypopygium ( Fig. 19 ). Anal tergite bands separated; median setae absent. Anal point long and slender; anal point crests absent. Superior volsella quadrangular, with five lateral robust setae; digitus very long, extending well beyond posteromedian corner of superior volsella. Inferior volsella slightly bent in median part, extending slightly beyond base of gonostylus. Median volsella slender and very long (58 µm), with several spatulate lamellae distally and 4–5 setiform lamellae on inner margin.

Remarks. The absence of anal crests in the male hypopygium of Paratanytarsus silentii sp. n. agrees with Paratanytarsus corbii and the undescribed species (op.cit.). The main characteristic that differentiates the male of P. s i l e n t i i sp. n. from these two species is the very long stem of the median volsella and digitus.

Figures

FIGURE 19. Paratanytarsus silentii sp. n., male. Hypopygium, dorsal view left, ventral view right. Scale: 100 µm.