Beardius longicaudatus, 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 : 46

Beardius longicaudatus sp. n.

( Figs 80–84 )

Type material. Holotype: male, BRAZIL, Amazonas State : Rio Preto da Eva , AM 010 Km 113, 24 m a.s.l., Ramal do Procópio Km 15, #41, Igarapé no Sítio Dois Irmãos, S02°40'36.6" W59°23'19.8", 28.ix.2008, Malaise trap suspended 3 m above the ground, J.O. Silva et al. ( MZSP) . Paratypes: 5 males, as holotype ( INPA, ZMBN, MZUFBA) .

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 long, narrowly spatulate without microtrichia in apical 1/3; and basal projection of the inferior volsella long, digitiform, bearing long lamellae reaching the apex of inferior volsella.

Etymology. From Latin longicaudatus , meaning long tailed, referring to the shape of the anal point.

Description

Male (n = 5–6, except when otherwise stated). Total length 2.12–2.39, 2.29 mm. Wing length 0.99–1.05, 1.02 mm. Total length / wing length 2.05–2.34, 2.23. Wing length / length of profemur 1.90–2.20, 2.02.

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

Head. AR 1.11–1.19, 1.15; ultimate flagellomere 423–471, 444 µm long. Temporal setae 8–10, 9; not well separated in inner and outer verticals and postorbitals. Clypeus with 9–11, 10 setae. Tentorium 89–106, 96 µm long; 23–33, 25 µm wide. Stipes 111–129, 119 µm long. Palpomere lengths (in µm): 25–30, 28; 23–30, 28; 86–99, 94; 121–139, 132; 182–200, 192. Third palpomere with 2 sensillae subapically, longest 10–13, 11 µm long.

Thorax ( Fig. 81 ). Scutal tubercle absent. Dorsocentrals 5–7, 6; acrostichals 4–6, 5; prealars 2. Scutellum with 4–6, 5 setae.

Wing ( Fig. 80 ). VR 1.39–1.46, 1.43. R with 5–8, 6 setae; R 4+5 with 2 setae at apex. Brachiolum with 2 setae. Remaining veins bare.

Legs. Spur of fore tibia (including scale) 32–37, 34 µm long; spur of mid tibia (including comb) 54–59, 56 µm long; spur of hind tibia (including comb) 59–70, 64 µm long. Width at apex of fore tibia 37–48, 43 µm; of mid tibia 37–43, 41 µm; of hind tibia 43–48, 46 µm. Lengths and proportions of legs as in Table 14.

Hypopygium ( Figs 82–84 ). Anal point narrowly spatulate, 43–63, 56 µm long, with microtrichia restricted to basal 2/3. Tergite IX without setae, tergal bands present. Laterosternite IX with 2–4, 3 setae. Phallapodeme 63–73, 68 µm long. Transverse sternapodeme 33–43, 38 µm long. Gonocoxite 94–106, 101 µm long. Superior volsella clavate, 46–56, 51 (4) µm long, with 4–5, 4 (4) dorsal and 4 (4) ventral setae, with microtrichia on ventral surface. Median volsella absent. Inferior volsella curved, clavate, 43–66, 56 (4) µm long, with 2 apical thin and 4–5, 4 subapical stout setae; projection arising from base of volsella, 78–96, 86 (4) µm long, with numerous, long lamellae. Gonostylus 96–114, 104 µm long. HR 0.90–1.08, 0.97. HV 2.00–2.42, 2.22.

Female and immatures. Unknown.

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

Figures

FIGURES 80–84. Beardius longicaudatus sp. n., male. 80—wing; 81—thorax; 82—hypopygium, lateral view; 83—anal point and tergite IX and dorsal aspect of left gonocoxite and gonostylus; 84—hypopygium with anal point and tergite IX removed, left dorsal aspect, right ventral aspect.