Gravatamberus nidularium, 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 : 49-53

Gravatamberus nidularium sp. n.

( Figs 58–73 ).

Gen. n. 2 Pinho et al., 2005: 46.

Type material: Holotype male with pupal exuviae, BRAZIL: Santa Catarina: Florianópolis ( UCAD), in Nidularium innocentii Lemaire , 29.iv.2004, reared, F.H. Platt ( MZUSP) . Paratypes: 4 males, as holotype except for 04–19.ix.2003, emergence trap, L.C. Pinho; 2 males, as holotype except for 19.ix–03.x.2003, emergence trap, L.C. Pinho; 1 larva tentatively associated, as holotype except for L.C. Pinho; 4 males, São Bento do Sul , 26º19’25.6’’S, 48º18’26.5’’W, 660 m a.s.l., 13–16.x.2001, Malaise trap, M.V. Yamada ; 1 male, São Francisco do Sul, Vila Glória , 26º13’40’’S, 48º40’49’’W, 6 m a.s.l., 14–17.x.2001, Malaise trap, M.V. Yamada . 1 male, São Paulo: Salesópolis, Estação Biológica Boracéia, Trilha dos pilões, 23°39'04.8''S 45°53'41.8''W, 02– 05.iv.2001, Malaise trap (Trilha-3), S.T.P. Amarante et al. ( BIOTA-FAPESP) ( MZUSP, UFSCar, ZMBN, ZSM) .

Diagnostic characters: The species can be separated from all other members of the genus by having more than 10 setae in cell m proximal to RM, costal extension ending well before wing tip, and AR about 0.50 (0.42–0.78).

Etymology: From Nidularium, the generic name of the bromeliad, N. innocentii Lemaire , in which the species was collected; the name is to be regarded as a noun in apposition.

Male (n = 10, except when otherwise stated). Total length 1.27–1.48, 1.34 mm. Wing length 0.74–1.12, 0.94 mm. Total length / wing length 1.27–1.80, 1.42. Wing length / length of profemur 2.29–2.58, 2.44. Coloration light brown; thorax light brown with darker markings on preepisternum, median anepisternum and notum; legs and tarsi uniformly light brown.

Head ( Fig. 58 ). Most specimens from the type locality with 13 flagellomeres; AR 0.42–0.49, 0.46 (4); ultimate flagellomere 102–163, 135 µm long; stout subapical seta 39–48 (3) µm long. Two specimens from the type locality have only 12 flagellomeres due to fusion of segments 12 and 13, AR 0.57–0.61, and ultimate flagellomere 170–172 µm long. All paratypes from São Bento do Sul have 13 flagellomeres; AR, 0.65–0.78, 0.74 (4); ultimate flagellomere 191–286, 243 (4) µm long. Temporal setae 6–8, 7; including 2–3, 3 inner verticals; 2–3, 2 outer verticals; and 1–3, 2 postorbitals. Clypeus with 8–13, 10 setae. Tentorium, stipes, and cibarial pump as in Figure 59 . Tentorium 86–100, 91 µm long; 14–18, 16 µm wide. Stipes 73–93, 83 µm long; 23–29 (3) µm wide. Palp segment lengths (in µm): 14–16, 15; 24–29, 27; 41–77, 66; 70–98, 81 (7); 100–123, 113 (6). Third palpomere with 2 sensilla clavata subapically; longest 9–13, 11 µm long.

Thorax ( Fig. 60 ). Antepronotum with 3–7, 4 setae. Dorsocentrals 13–20, 16; acrostichals 8–14, 11 (9); prealars 3–5, 4; supraalar 1. Scutellum with 2–5, 4 setae.

Wing ( Fig. 61 ). VR 1.30–1.56, 1.38. C extension 86–107, 98 µm long. Brachiolum with 1–2, 1 seta; Sc with 13–21, 16 seta; C extension with 12–20, 17 non-marginal setae; R with 14–19, 16 setae; R 1 with 6–13, 11 setae; R 4+5 with 13–19, 16 setae; RM with 0–1, 0 seta; M with 0–1, 0 seta; M 1+2 with 28–48, 42 setae; M 3+4 with 13–23, 19 setae; Cu with 10–19, 15 setae; Cu 1 with 9–16, 14 setae; PCu with 28–40, 32 setae; An with 12–21, 16 setae. Cell m with 10–18, 15 setae proximal to RM; r 4+5 with 150–200 setae; m 1+2 with 150–200 setae; m 3+4 with 33–89, 69 setae; cu + an with 93–148, 121 setae.

Legs. Spur of foretibia 25–36, 31 µm long; spurs of midtibia 23–29, 25 µm and 14–16, 15 µm long; spurs of hind tibia 27–43, 37 µm and 14–20, 16 µm long. Width at apex of foretibia 23–25, 24 µm; of midtibia 23– 25, 24 µm; of hind tibia 29–32, 30 µm. Comb with 9–11, 10 setae; longest 32–48, 38 µm; shortest 20–23, 21 µm long. Lengths and proportions of legs as in Table 11.

Hypopygium ( Figs 62–63 ). Tergite IX without setae; laterosternite IX with 2–4, 3 setae. Phallapodeme 50–61, 58 µm long; transverse sternapodeme 52–61, 57 µm long. Gonocoxite 84–129, 115 µm long. Gonostylus 50–66, 61 µm long; megaseta 4–7, 6 µm long. HR 1.68–2.11, 1.87; HV 2.00–2.65, 2.21.

Pupa (n = 1). Total length 1.79 mm. Exuviae transparent.

Cephalothorax ( Figs 64–65 ). Frontal apotome smooth. Ocular field apparently with 1 postorbital and 1 vertical, not measurable. Antennal sheath smooth. Three median antepronotals about 38 µm long. Precorneals 3, 48, 16, and 20 µm long, respectively. Dorsocentrals 3, Dc 2 29 µm, Dc 3 34 µm, and Dc 4 32 µm long. Distance between Dc 2 and Dc 3 7 µm, between Dc 3 and Dc 4 18 µm. Prealar 16 µm long.

Abdomen ( Figs 66–67 ). Numbers of caudal spines on tergites II–VIII as: 22, 27, 25, 26, 22, 17, 14. Length (in µm) of longest caudal spine on tergites II–VIII (in µm) as: 7, 11, 11, 13, 14, 18, 20. Anal lobe 143 µm long, with two macrosetae about 40 µm long. Genital sac overreaches anal lobe by 14 µm.

Larva (n = 1) fourth instar (tentatively associated). Head capsule 186 µm long; postmentum 61 µm long. Larva cleared, color not discernable.

Head. Antenna as in Figure 68 ; segment lengths in µm: 23, 9, 4, 4, 2. Blade 27 µm long, longer than flagellum; apical style of second segment 4 µm long. S I plumose ( Fig. 69 ), other labral setae simple. Mandible ( Fig. 70 ) 66 µm long, with apical tooth and four inner teeth, fourth tooth fused with mola; seta subdentalis slender; seta interna with seven branches. Premandible ( Fig. 71 ) 34 µm long. Mentum ( Fig. 72 ) 57 µm wide; median tooth 7 µm long, 9 µm wide; with five lateral teeth.

Abdomen ( Fig. 73 ) with sparse setae and tufts, more evident on last segments. Anterior parapods fused, with numerous claws, all simple; posterior parapods 68 µm long. Supraanal seta 14 µm long. Procerci 9 µm wide, 11 µm long; with 8 setae, all about 110 µm long. Anal tubules apparently absent.

Remarks: The males from São Bento do Sul have higher AR than the males from Florianópolis (see description) and might belong to a separate species. The pupa is associated with the male adult by rearing, while the larva is tentatively associated. However, only three orthoclad genera occur in the bromeliads surveyed, Genus H sensu Epler, Limnophyes with one abundant and one rare species, and Gravatamberus gen. n. As the larvae of the other genera are associated, the larva described here most probably is correctly associated. For more information on the chironomid fauna in the bromeliads, see Pinho et al. (2005).

Biology and distribution: The species was collected in emergence traps covering the bromeliad Nidularium innocentii Lemaire ( Pinho et al. 2005; Marcondes & Pinho 2005). Adults were also collected in Malaise traps in the Atlantic Rainforest in the Santa Catarina and São Paulo states in Brazil.

Figures

FIGURES 58–63. Gravatamberus nidularium sp. n., male. 58—head; 59—tentorium, stipes, and cibarial pump; 60— thorax; 61—wing; 62—anal point and tergite IX and dorsal aspect of left gonocoxite and gonostylus; 63—hypopygium with anal point and tergite IX removed, dorsal aspect to the left and ventral aspect to the right.

FIGURES 64–67. Gravatamberus nidularium sp. n., pupa. 64—frontal apotome; 65—cephalothorax; 66—tergites; 67—sternites.

FIGURES 68–73. Gravatamberus nidularium sp. n., larva. 68—antenna; 69—S I; 70—mandible; 71—premandible; 72—mentum; 73—anal end.