Saetherolabis siriype, Andersen, Trond, Mendes, Humberto F. & Pinho, Luiz C., 2012

Andersen, Trond, Mendes, Humberto F. & Pinho, Luiz C., 2012, Two new species of Saetherolabis Andersen et Mendes, 2007 from Brazil (Diptera: Chironomidae, Orthocladiinae), Zootaxa 3300, pp. 62-68 : 65-67

Saetherolabis siriype sp. n.

( Figs 7–12 )

Type Material: Holotype male: BRAZIL, Sergipe State, Areia Branca, Serra Itabaiana, riacho Coqueiro, 05.viii.2009, light trap, A.R. Calor & L. Lecci ( MZUSP).

Etymology: From the native Brazilian language Tupi, siri and ype, ‘crab’ and ‘river, sea’, meaning river filled with crabs. The name is an allusion for the type locality and is to be treated as a noun in apposition.

Diagnostic characters: The species can be separated from both S. pectinata and S. iperuype on the straight transverse sternapodeme with strong oral projections and on the oral branch of inferior volsella which is strongly bent with apical one-half almost parallel to caudal branch.

Description: Male (n = 1). Total length 1.24 mm. Wing length 787 μm. Total length / wing length 1.58. Wing length / length of profemur 2.76.

Coloration. Head and antennae dark brown; thorax light brown with dark brown vittae, median anepisternum, preepisternum, scutellum and postnotum; abdominal segments I–V and hypopygium dark brown, abdominal segments VI–VII light brown; legs with femur brown, tibia and tarsus light brown.

Head. AR 1.20. Antenna with 11 flagellomeres, ultimate flagellomere 241 μm long. Temporal setae 4 including 2 inner verticals and 2 outer verticals. Clypeus with 4 setae. Cibarial pump, tentorium and stipes as in Figure 7 . Tentorium 79 μm long, 11 μm wide at sieve pore. Stipes 59 μm long, 34 μm wide. Palp segment lengths / widths (in μm): 11 / 12, 10 / 12, 23 / 18, 23 / 14, fifth palpomere lost. Third palpomere with 5 sensilla clavata in subapical sensillum coeloconicum ( Fig. 8 ), longest about 9 μm long.

Thorax ( Fig. 9 ). Antepronotum with 3 setae. Dorsocentrals 8, acrostichals apparently absent, prealars composed of 3 posterior and 1 anterior. Scutellum with 2 setae.

Wing ( Fig. 10 ). VR 1.54. Costal extension 109 μm long. Brachiolum with 1 seta.

Legs. Spur of fore tibia 27 μm long, spurs of mid tibia 18 μm and 10 μm long, spurs of hind tibia 41 μm and 12 μm long. Width at apex of fore tibia 24 μm, of mid tibia 20 μm, of hind tibia 25 μm. Comb with 10 setae, longest 25 μm long, shortest 16 μm long. With row of spine-like setae on all tarsomeres of fore-, mid- and hind legs, particularly distinct on ta1; setae on ta1 of fore leg 14–18 μm long. Lengths and proportions of legs as in Table 2.

Hypopygium ( Figs 11–12 ). Tergite IX with 4–5 strong setae to each side of anal point; laterosternite IX with single strong seta. Anal point 41 μm long, 9 μm wide at base, 6 μm wide at apex, without microtrichia. Phallapodeme 54 μm long; transverse sternapodeme 54 μm long, straight, with strong oral projections. Virga 10 μm long. Gonocoxite 104 μm long. Inferior volsella deeply split; oral branch strongly bent, 20 μm long, 3 μm wide medially; caudal branch straight, 12 μm long, 11 μm wide medially. Superior volsella barely indicated. Gonostylus 58 μm long, without crista dorsalis; megaseta 8 μm long. HR 1.80; HV 2.14.

Distribution: The species is known from a single male collected in a light trap in Sergipe State, near the Brazilian northeastern coast.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 295 328 180 68 58 32 35 0.55 4.13 3. 46 3.2 p2 334 338 149 72 58 30 29 0.44 4.35 4. 51 3.1 p3 317 342 216 101 90 34 31 0.63 3.40 3.05 3.2

Figures

FIGURES 7 – 12. Saetherolabis siriype sp. n., male. 7 – tentorium, stipes, and cibarial pump; 8 – palpomeres 1 - 4; 9 – thorax; 10 – wing; 11 – hypopygium, dorsal aspect; 12 – hypopygium with anal point and tergite IX removed, dorsal aspect to the left and ventral aspect to the right.