Beardius curticaudatus, 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 : 32-35

Beardius curticaudatus sp. n.

( Figs 49–53 )

Type material. Holotype: male, BRAZIL, Amazonas State : Manaus, AM 010 Km 26, 55 m a.s.l., Adolfo Ducke Forest Reserve, #64, Igarapé Bolívia (Ig. 23), S02°59'14.8" W59°56'47.1", 09–12.xi.2008, Malaise trap suspended 3 m above the ground, U.G. Neiss et al. ( MZSP) . Paratypes: 2 males, as holotype ( MZSP, INPA) . 2 males, Novo Airão, AM 352 Km 9, 123 m a.s.l., Igarapé no Sítio do Sr. Valdenor, #6, S02°42'04.5" W06°55'23.4", 11– 14.viii.2008, Malaise trap suspended 3 m above the ground, A.M.O. Pes et al. ( MZUFBA, ZMBN) .

Diagnostic characters. The species belongs in the xylophilus group. The male can be separated from all other members of the genus by the combination of the following characters: acrostichals present; anal point short; and basal projection of inferior volsella long, digitiform, bearing long lamellae reaching the apex of the inferior volsella.

Etymology. From Latin curticaudatus , meaning short tailed, referring to the size of the anal point.

Description

Male (n = 4–5). Total length 2.18–2.71, 2.52 mm. Wing length 1.06–1.12, 1.09 mm. Total length / wing length 2.07–2.61, 2.32. Wing length / length of profemur 1.93–2.15, 2.00.

Coloration. Head and abdomen pale; thorax pale, with vittae and scutum stramineous. Legs pale.

Head. AR 1.00–1.32, 1.25; ultimate flagellomere 460–519, 508 µm long. Inner vertical 1; outer verticals 3–4, 4; postorbitals 3–4, 4. Clypeus with 10–13, 11 setae. Tentorium 71–116, 96 µm long; 23–35, 30 µm wide. Stipes 121–129 (3) µm long. Palpomere lengths (in µm): 25–46, 35; 28–46, 35; 99–129, 114; 124–167, 149; 182–233, 202. Third palpomere with 3–4, 4 sensillae subapically, longest 13–15, 14 µm long.

Thorax ( Fig. 50 ). Scutal tubercle absent. Dorsocentrals 7–9, 8; acrostichals 7–8, 8; prealars 2. Scutellum with 6 setae.

Wing ( Fig. 49 ). VR 1.36–1.50, 1.43. R with 4–8, 6 setae; R 4+5 with 2 setae at apex. Brachiolum with 2 setae. Remaining veins bare.

Legs. Spur of fore tibia (including scale) 37–48, 43 µm long; spur of mid tibia (including comb) 54–64, 59 µm long; spur of hind tibia (including comb) 64–70, 67 µm long. Width at apex of fore tibia 43–48, 46 µm; of mid tibia 43–54, 48 µm; of hind tibia 48–54, 51 µm. Lengths and proportions of legs as in Table 8.

Hypopygium ( Figs 51–53 ). Anal point small, bluntly triangular, 5–7, 6 µm long, arising from broadly rounded posterior protrusion of tergite IX. Tergite IX without setae, tergal bands present. Laterosternite IX with 2–3, 2 setae. Phallapodeme 56–58, 57 µm long. Transverse sternapodeme 46–56, 51 µm long. Gonocoxite 101–104, 102 µm long. Superior volsella digitiform, 48–68, 56 µm long, with 3–5, 4 dorsal, 2 apical, and 2 ventral setae, without microtrichia. Median volsella absent. Inferior volsella strongly curved, clavate, 73–89, 83 µm long, with 2 apical thin and 4–5, 4 subapical stout setae, with microtrichia in basal 1/3; projection arising from base of volsella, 66–73, 71 µm long, with about 12 long, curved lamellae. Gonostylus 99–116, 109 µm long. HR 0.89–1.02, 0.97. HV 2.11– 2.40, 2.30.

Female and immatures. Unknown.

Distribution. The species is collected in the Amazonas State in Brazil.

Figures

FIGURES 49–53. Beardius curticaudatus sp. n., male. 49—wing; 50—thorax; 51—hypopygium, lateral view; 52—anal point and tergite IX and dorsal aspect of left gonocoxite and gonostylus; 53—hypopygium with anal point and tergite IX removed, left dorsal aspect, right ventral aspect.