Gravatamberus curtus, Mendes & Andersen, 2008

Mendes, Humberto Fonseca & Andersen, Trond, 2008, A review of Antillocladius Saether and Litocladius Mendes, Andersen et Saether, with the description of two new Neotropical genera (Diptera, Chironomidae, Orthocladiinae), Zootaxa 1887 (1), pp. 1-75 : 45-47

Gravatamberus curtus sp. n.

( Figs 48–52 )

Type material: Holotype male, MEXICO: Campeche: Calakmul, Ejido Novo Becan, El Chorro , 18º35’25.5’’N, 89º15’28.8’’W, 130 m a.s.l., 30.iv.1997, Malaise trap, A. Contreras-Ramos et al. ( ZMBN) . Paratypes: 2 males, COSTA RICA: Guanacaste: Caccao , 4–7.v.1993, Malaise trap, T. Andersen ( MZUSP, ZMBN) .

Diagnostic characters: The species can be separated from all other members of the genus by having less than 10 setae in cell m proximal to RM; Sc with 6–15 setae; costal extension 68–86 µm long, ending well before wing tip; and AR 0.64–0.69.

Etymology: From Latin, curtus , meaning short, referring to the short costal extension.

Male (n = 1–3). Total length 1.29–1.43 mm. Wing length 0.71–0.84 mm. Total length / wing length 1.63– 1.81. Wing length / length of profemur 2.43–2.68. Coloration brown; thorax light brown with darker markings on preepisternum, median anepisternum and notum; legs and tarsi uniformly light brown.

Head. AR 0.64–0.69. Antenna with 12 flagellomeres, ultimate flagellomere 173–187 µm long, stout subapical seta 32–50 µm long. Temporal setae 8–10, including 3–4 inner verticals, 2–3 outer verticals, and 3–4 postorbitals. Clypeus with 8–11 setae. Tentorium, stipes, and cibarial pump as in Figure 48 . Tentorium 61–73 µm long, 11–13 µm wide. Stipes 84–86 µm long. Palp segment lengths (in µm): 14–16, 20–23, 57–61, 57–68, 75–116. Third palpomere with 2 sensilla clavata subapically, longest 9–11 µm long.

Thorax ( Fig. 49 ). Antepronotum with 1–3 setae. Dorsocentrals 8–13; acrostichals 7–14, all scalpellate; prealars 4–7, extended anteriorly; supraalar 1. Scutellum with 2 setae.

Wing ( Fig. 50 ). VR 1.33–1.41. C extension 68–86 µm long. Brachiolum with 1 seta, Sc with 6–15 seta, C extension with 7–8 non-marginal setae, R with 10–17 setae, R 1 with 6–8 setae, R 4+5 with 5–18 setae, M 1+2 with 23–35 setae, M 3+4 with 8–17 setae, Cu with 10–13 setae, Cu 1 with 6–11 setae, PCu with 16–24 setae, An with 10–14 setae. Cell m with 1–7 setae, r 4+5 with about 75–100 setae, m 1+2 with about 60–90 setae, m 3+4 with 15–49 setae, cu with 0–19 setae, and an with 11–58 setae.

Legs. Spur of foretibia 27–32 µm long, spurs of midtibia 20–29 µm and 14–16 µm long, spurs of hind tibia 32–36 µm and 14–18 µm long. Width at apex of foretibia 20 µm, of midtibia 20–23 µm, of hind tibia 25– 27 µm. Comb with 11 setae, longest 23–34 µm, shortest 14–20 µm long. Lengths and proportions of legs as in Table 9.

Hypopygium ( Figs 51–52 ). Tergite IX with 0–2 setae, laterosternite IX with 3–5 setae. Phallapodeme 52– 59 µm long, transverse sternapodeme 43–61 µm long. Gonocoxite 95–111 µm long. Gonostylus 50–54 µm long, megaseta 4–9 µm long. HR 1.91–2.04, HV 2.48–2.62.

Biology and distribution: The species is known from Mexico and Costa Rica where males were collected in Malaise traps. In Mexico it was taken in the Calakmul Biosphere Reserve, a large lowland rainforest reserve on the Yucatan Peninsula. In Costa Rica it was taken in a mountain rainforest in the Guanacaste Province

Figures

FIGURES 48–52. Gravatamberus curtus sp. n., male. 48—tentorium, stipes, and cibarial pump; 49—thorax; 50—wing; 51—anal point and tergite IX and dorsal aspect of left gonocoxite and gonostylus; 52—hypopygium with anal point and tergite IX removed, dorsal aspect to the left and ventral aspect to the right.