Saetherocladius triangulatus, Andersen, Trond, Mendes, Humberto F. & Pinho, Luiz C., 2010

Andersen, Trond, Mendes, Humberto F. & Pinho, Luiz C., 2010, Four new species of Saetherocladius Andersen et Mendes from Mata Atlântica, Brazil (Diptera: Chironomidae: Orthocladiinae), Zootaxa 2608, pp. 45-56 : 51-53

Saetherocladius triangulatus sp. n.

( Figs 14–19 )

Type material. Holotype male, slide mounted in Canada balsam. Brazil: São Paulo State, Parque Estadual Intervales, Ribeirão Grande, Barra Grande, 10–13.xii.2000, Malaise trap (Trilha 4), M.T. Tavares et al. ( MZUSP). Paratypes 1 male, São Paulo State, Estação Biológica Boracéia, Salesópolis, Trilha dos Pilões, 23o39'04.8''S, 5o53'41.8''W, 30.iii.2001, Malaise trap ( Mata 3), S.T.P. Amarante et al.; 3 males, as previous except 23o39'05.3''S, 5o53'51.7''W, 2–5.iv.2001, Malaise trap (Bosque 6) ( MZUSP, ZMBN).

Diagnostic characters. The species can be separated from the other species in the genus by the following combination of characters: AR 0.45–0.50; virga 8–11 µm long; inferior and superior volsella not well separated; inferior volsella bluntly triangular, without dorsal microtrichia; gonostylus with distinct outer projection and anal point spatulate.

Etymology. From Latin triangulus, having three angles, referring to the shape of the gonostylus.

Male (n = 4–5, except when otherwise stated). Total length 1.10–1.37, 1.23 mm. Wing length 682–857, 751 µm. Total length / wing length 1.54–1.69, 1.62. Wing length / length of profemur 2.47–2.66, 2.53.

Coloration. Thorax and head brown; legs, abdomen and antennae light brown.

Head. AR 0.45–0.50, 0.48. Ultimate flagellomere 122–176, 139 µm long. Temporal setae 6–8, 7 including 2–4, 3 inner verticals; 3–4, 3 outer verticals and 0–1, 1 postorbital. Clypeus with 5–6, 6 setae. Tentorium, stipes and cibarial pump as in Figure 14 . Tentorium 77–93, 88 µm long; 12–16, 14 µm wide at sieve pore. Stipes 61–75, 68 µm long; 20–25 (2) µm wide. Palp segment lengths / widths (in µm): 11–16, 14 / 10–12, 11; 23–27, 25 / 11–14, 13; 50–59, 55 / 17–20, 19; 41–54, 47 / 11–14, 12; 81–84 (3) / 9–11 (3). Third palpomere with 3–6, 5 sensilla clavata subapically; longest 8–11, 9 µm long.

Thorax ( Fig. 15 ). Antepronotum with 2–4, 3 setae. Dorsocentrals 11–14, 12; acrostichals 9–13, 12 starting close to antepronotum; prealars divided into 3–4, 3 posterior and 2–4, 3 anterior setae; supraalar 1. Scutellum with 4 setae.

Wing ( Fig. 16 ). VR 1.37–1.45, 1.40. Costal extension 0–14, 7 µm long. Brachiolum with 1 seta; R with 1– 3, 2 setae; other veins bare. Squama with 0–1, 0 seta.

Legs. Spur of fore tibia 31–36, 34 µm long; spurs of mid tibia 12–15, 13 µm and 9–11, 10 µm long; spurs of hind tibia 26–34, 29 µm and 10–14, 12 µm long. Width at apex of fore tibia 20–23, 22 µm; of mid tibia 18– 20, 19 µm; of hind tibia 26–30, 28 µm. Comb with 14–16, 15 setae; longest 23–27, 25 µm long; shortest 13– 16, 15 µm long. Lengths and proportions of legs as in Table 4.

Hypopygium ( Figs 17–19 ). Anal point 16–36, 25 µm long; 7–10, 8 µm wide at base; 2–3, 2 µm wide at apex; with 4–6, 5 setae basally. Laterosternite IX with 2–5, 4 setae. Phallapodeme 42–59, 50 µm long; transverse sternapodeme 41–52, 48 µm long. Virga 8–11, 10 µm long. Gonocoxite 91–105, 95 µm long. Gonostylus 50–52, 51 µm long, with large, subrectangular crista dorsalis and distinct outer projection; megaseta 4–8, 6 µm long. HR 1.76–2.00, 1.88. HV 2.19–2.63, 2.43.

Female and immatures. Unknown.

Distribution and ecology. The species was collected in Malaise traps in Parque Estadual Intervales and in the Reserva Biológica Boracéia, indicating a distribution in the coastal areas of São Paulo State. Both nature reserves have mainly primary Atlantic forest.

Figures

FIGURES 14 – 19. Saetherocladius triangulatus sp. n., male. 14 — tentorium, stipes and cibarial pump; 15 — thorax; 16 — wing; 17 — anal point and tergite IX and dorsal aspect of left gonocoxite and gonostylus; 18 — hypopygium with tergite IX and anal point removed, dorsal aspect to the left, ventral aspect to the right; 19 — gonostylus with crista dorsalis projecting upwards.