Beardius hirtidorsum, Pinho & Mendes & Andersen, 2013

Pinho, Luiz Carlos, Mendes, Humberto Fonseca & Andersen, Trond, 2013, Revision of Beardius Reiss et Sublette, 1985 (Diptera: Chironomidae), with the description of twenty new species, Zootaxa 3742 (1), pp. 1-78 : 40-42

Beardius hirtidorsum sp. n.

( Figs 67–70 )

Type material. Holotype male, BRAZIL, Roraima State: Boa Vista, Lago Magalhães , 10.xii.1971, F. Reiss ( ZSM) . Paratypes: 3 males, as holotype ( MZSP) . 3 males, Mato Grosso State: Ribeirão Cascalheira, Afluente Ribeirão Bonito , S12°55'36" W51°53'28", 08.x.2007, light trap, L.C. Pinho et al. ( ZMBN, MZUFBA) .

Diagnostic characters. The species belongs in the parcus group. The male can be separated from all other members of the genus by the tapering apex of the superior volsella; and the conspicuous, long macrotrichia in posterior part of scutum.

Etymology. From Latin hirtidorsum , meaning hairy back, referring to the diagnostic macrotrichia on scutum.

Description

Male (n = 5–7, except when otherwise stated). Total length 2.24–3.06, 2.57 mm. Wing length 1.14–1.23, 1.17 mm. Total length / wing length 1.95–2.48, 2.18. Wing length / length of profemur 2.02–2.09, 2.06.

Coloration. Head, thorax and abdomen pale. Legs pale.

Head. AR 1.04–1.18, 1.11; ultimate flagellomere 399–440, 416 µm long. Inner verticals 2; outer verticals 4; postorbitals 2–3, 2. Clypeus with 9–13, 11 setae. Tentorium 81–124, 103 (4) µm long; 26–30, 28 (4) µm wide. Stipes 103–116, 112 µm long. Palpomere lengths (in µm): 26–30, 28; 26–30, 28; 67–95, 75; 102–118, 112; 164– 185, 175 (4). Third palpomere with 2–4, 3 sensillae subapically; longest 12–16, 14 µm long.

Thorax ( Fig. 68 ). Scutal tubercle present; scutum with distinct, long macrotrichia in posterior 1/2. Dorsocentrals 5–7, 6; acrostichals absent; prealars 2. Scutellum with 4–5, 4 setae.

Wing ( Fig. 67 ). VR 1.36–1.46, 1.41. R with 0–4, 1 seta; R 4+5 with 2–4, 3 setae at apex. Brachiolum with 2 setae. Remaining veins bare.

Legs. Spur of fore tibia (including scale) 36–40, 38 µm long; spur of mid tibia (including comb) 40–56, 48 µm long; spur of hind tibia (including comb) 48–60, 56 µm long. Width at apex of fore tibia 36–40, 38 µm; of mid tibia 36–40, 37 µm; of hind tibia 40–48, 46 µm. Lengths and proportions of legs as in Table 11.

Hypopygium ( Figs 69–70 ). Anal point bluntly triangular, 4–8, 6 µm long, barely overreaching posterior margin of tergite IX. Tergite IX without setae, tergal bands present. Laterosternite IX with 2–3, 2 setae. Phallapodeme 43– 60, 53 µm long. Transverse sternapodeme 26–39, 33 µm long. Gonocoxite 93–102, 98 µm long. Superior volsella with narrow, curved apex, 28–35, 32 µm long, with 6–9, 7 dorsal and 1–2, 2 ventral setae, with microtrichia dorsally. Median volsella 2–3, 2 µm long, with 2 apical setae, longest 18–24, 22 µm long. Inferior volsella slightly curved, 32–51, 43 µm long, with 2 apical thin and 5–7, 6 stout bifid subapical setae, with microtrichia dorsally in basal 1/2; projection absent. Gonostylus 93–112, 102 µm long. HR 0.91–1.04, 0.98. HV 2.22–2.73, 2.49.

Female and immatures. Unknown.

Distribution. The species is collected in the Mato Grosso and Roraima states in Brazil.

Figures

FIGURES 67–70. Beardius hirtidorsum sp. n., male. 67—wing; 68—thorax; 69—anal point and tergite IX and dorsal aspect of left gonocoxite and gonostylus; 70—hypopygium with anal point and tergite IX removed, left dorsal aspect, right ventral aspect.