Culicoides rhombus Santarem, Felippe-Bauer & Castellon, sp. nov.

Culicoides rhombus Santarém, Felippe-Bauer & Castellón sp. nov.

Figs. 8 A–F; Fig. 9

Diagnosis. Female: This species is easily distinguished by the following combination of characters: palpus 3rd segment rhomboidal, with a shallow, well - developed irregular sensory pit that reaches the extreme distal portion of segment; PR 2.5–3.0; proboscis long.

Female. Head. Brown. Eyes bare (Fig. 8 B), narrowly separated, smaller than ½ ommatidium. Pedicel brown, flagellum pale brown, first eight flagellomeres paler on proximal ½; AR 1.05–1.10 (1.06, n=4) (Fig. 8 C); sensilla coeloconica on flagellomeres 1,6–8, two on 1, three on 6, two on 7 and three on 8. Palpus (Fig. 8 F) brown, 3rd segment swollen at middle length, rhomboid, with a shallow, well - developed irregular sensory pit that reaching the distal portion of segment; PR 2.5–3.0 (2.6, n=7). Proboscis long; P/H ratio 1.08–1.28 (1.13, n=6); mandible with 23 teeth.

Thorax. Dark brown. Scutum without distinct pattern in slide mounted specimens. Wing (Fig. 8 A) with contrasting pattern: second radial cell including dark spot; pale spot over R-M extending from M1 to the costal margin, subdivided; r3 with four small and separated pale spots: first, rounded, between the second radial and M1; second, poststigmatic, extending behind second radial cell, abutting wing margin; third, rounded, in middle of cell, similar to the second one; fourth, distal pale spot slightly reaching wing margin; m1 with two pale spots, the distal one far from the wing margin and greater to the proximal one; m2 with four pale spots: one proximal, near CuA, two between medial and mediocubital forks, a distal one not reaching wing margin; cua1 with a rounded pale spot in the middle of cell; anal cell with a faint basal pale area near base and a distal pale spot near mediocubital fork; wing base with a pale spot on M; M1, M2 and CuA1 with pale apex; macrotrichia scarcely distributed on the distal third of wing; wing length 0.85–0.97 (0.92, n=7) mm; breadth 0.40–0.45 (0.43, n=7) mm; CR 0.64–0.66 (0.65, n=7). Halter knob browm, stem pale. Legs (Fig. 8 D) mostly brown, femora with subapical pale bands, tibiae with subbasal pale bands; hind tibia pale apically; hind tibial comb with four spines, the one nearest the spur longest.

Abdomen. Brown. Two slightly unequal ovoid spermathecae (Fig. 8 E), measuring 45.5 µm (n=6) by 37 µm (n=6) and 38.7 µm (n=5) by 32.5 µm (n=5), with sclerotized ducts measuring 4.3 µm (n=6); long, slender, rudimentary third spermatheca present (17.5 µm).

Male. Unknown.

Type data and depository. Holotype female, BRAZIL, Roraima, Maracá, 28.VII.1987, CDC light trap, "mata", E. Castellon & S. Gomes cols. (CCER). Paratypes six females, same data except: one, 28.VI.1987, "mata 10m " (CCER); one, 30.VII.1987, "mata 5m " (MNRJ); one, 22.VII.1987, "mata 5m ” (ILMD); one, 27.VII.1987, "mata 5m ” (ILMD); one, Amazonas, Rio Pardo, 17-18.2010, CDC light trap, Capoeira, F. Pessoa col.; one same data except VI-VIII.2010, "borda de floresta" (ILMD).

Distribution and bionomics. This species is restricted to Brazilian states of Roraima and Amazonas (Fig. 9). It was associated with forest environment far from coastal regions.

Etymology. The name of this species is related with the rhomb shape aspect of the third palpal segment (Greek—rhómbos= rhombus).