Antillocladius atalaia, 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 : 21-23

Antillocladius atalaia sp. n.

( Figs 7–11 )

Type material: Holotype male, Brazil: Rio de Janeiro: Arraial do Cabo, Morro do Atalaia , 10.i.2006, sweep net (swarming), H.F. Mendes ( MZUSP) . Paratypes: 9 males, same data as holotype ( ZSM, ZMBN) .

Diagnostic characters: The species can be separated from all other members of the genus by the presence of setae on squama, bifid inferior volsella, and long virga.

Etymology: Named after the type locality; the name is to be regarded as a noun in apposition.

Male (n = 10, except when otherwise stated). Total length 1.87–2.14, 2.03 mm. Wing length 1.14–1.30, 1.22 mm. Total length / wing length 1.45–1.76, 1.66. Wing length / length of profemur 2.19–2.50, 2.28. Coloration brown, thorax dark brown without distinct marks.

Head. AR 1.23–1.54, 1.38. Ultimate flagellomere 400–479, 439 µm long. Temporal setae 7–14, 11; including 1–5, 4 inner verticals; 3–5, 4 outer verticals; and 3–4, 3 postorbitals. Clypeus with 3–8, 6 setae. Tentorium, stipes, and cibarial pump as in Figure 7 . Tentorium 91–120, 108 µm long; 18–22, 20 µm wide. Stipes 102–136, 117 µm long. Palp segment lengths (in µm): 16–24, 21; 36–54, 44; 84–113, 96; 77–100, 87; 95–120, 107 (9). Third palpomere with 3–6, 5 sensilla clavata subapically; longest 9–16, 13 µm long.

Thorax ( Fig. 8 ). Antepronotum with 2–5, 3 setae. Dorsocentrals 7–13, 10; acrostichals 15–23, including 3–8, 4 simple anterior and 10–19, 14 scalpellate; prealars 3–5, 4; supraalar 1. [One paratype with weak seta on left side of preepisternum, others lack seta]. Scutellum with 6–10, 8 setae.

Wing ( Fig. 9 ). VR 1.22–1.39, 1.32. C extension 57–86, 72 µm long. Brachiolum with 1–2, 1 setae; R with 0–5, 2 setae; R 1 with 0–2, 1 setae, other veins and membrane bare. Squama with 4–11, 8 setae.

Legs. Spur of foretibia 50–59, 54 µm long; spurs of midtibia 25–38, 32 µm and 23–27, 25 µm long; spurs of hind tibia 43–59, 51 µm and 18–27, 24 µm long. Width at apex of foretibia 29–34, 31 µm; of midtibia 32– 34, 33 µm; of hind tibia 39–45, 42 µm. Comb with 12–16, 14 setae; longest 29–48, 37 µm; shortest 16–23, 20 µm. Lengths and proportions of legs as in Table 1.

Hypopygium ( Figs 10–11 ). Tergite IX covered with microtrichia; laterosternite IX with 5–8, 7 setae. Anal point triangular, 36–61 (3) µm long, 25–29 (3) µm wide at base, 6–9 (3) µm wide at apex, with 10–19, 14 setae. Phallapodeme 79–98, 87 µm long; transverse sternapodeme 27–43, 34 µm long. Virga 25–48, 40 µm long composed of two spines. Gonocoxite 159–193, 177 µm long. Gonostylus 77–98, 87 µm long; megaseta 14–17, 15 µm long. HR 1.93–2.13, 2.02; HV 2.15–2.56, 2.33.

Biology and distribution: The species was collected together with A. axitiosus sp. n., A. brazuca sp. n., A. folius , and A. ultimus sp. n. in a hill-side close to the sea in Rio de Janeiro State, Brazil ( Fig. 12 ). All five species were collected swarming together from noon to 6:00 pm. The air temperature was around 30º C. The hill-side is covered by restinga vegetation with large cactus plants. There are no streams nearby, but some phytotelmata (mostly bromeliads) and a few rock-pools along the coast. At the sampling site the soil was covered by mosses and lichens, which could be the habitat of the larvae. The immatures of A. musci , A. folius and A. pluspilalus are all terrestrial and have been found living in mosses and lichens on tree-trunks and stones.

Figures

FIGURE 12. Restinga vegetation in Morro do Atalaia, Arraial do Cabo, Rio de Janeiro State, Brazil, 10.i.2006; the type locality of Antillocladius atalaia sp. n., A. brazuca sp. n., and A. ultimus sp. n. (Photo: H. F. Mendes).

FIGURES 7–11. Antillocladius atalaia sp. n., male. 7—tentorium, stipes, and cibarial pump; 8—thorax; 9—wing; 10— anal point and tergite IX and dorsal aspect of left gonocoxite and gonostylus; 11—hypopygium with anal point and tergite IX removed, dorsal aspect to the left and ventral aspect to the right.