Female: only species of Culicoides in the Neotropical Region with the following combination of features: 2^nd radial cell in dark spot, r₃ with four sparsely distributed pale spots, r-m crossvein pale; hind femur with subapical pale band; scutum with two anterior submedian clover-leaf shaped spots; third palpal segment elongate, slightly swollen, cylindrical, without a sensory pit but with capitate sensilla scattered on the surface cuticle. Male: only species in the Neotropical Region with the following combination of features: tergite 9 with a posteromedial notch, parameres with slightly sinuous stem, swollen on mid-portion and without a ventral lobe and the basal arch of aedeagus extending 2/3 of total length.

Female. Head (Fig. 2d). Brown. Eyes bare, separated by distance equal to diameter of nearly one ommatidium (Fig. 2a). Antennal pedicel brown; flagellum pale brown, flagellomeres 1–8 pale on proximal ½; AR 0.90–1.00 (0.95, n = 8); sensilla coeloconica on flagellomeres 1, 6–8, two on 1, three on 6, three or four on 7 and four on 8. Palpus (Fig. 2b) brown; third segment elongate cylindrical, slightly swollen, without sensory pit, with sensilla scattered on surface; PR 3.30–3.90 (3.54, n = 12). Proboscis moderately long; P/H ratio 0.87–1.00 (0.95, n = 13); mandible (Fig. 2c) with 19–25 (22, n = 12) teeth.

Thorax (Fig. 2e). Dark brown, with prominent pattern of well-defined yellowish patches, humeral depression pale. Scutum with two anterior submedian clover-leaf shaped spots, two posterior submedian pale areas; lateral portion with anterior, posterior pale areas; prescutellar depressions pale; scutellum with yellowish lateral margins; postscutellum brown with pale median area. Wing (Fig. 1a) with contrasting pattern of pale and dark spots; distal ½ of 1^st, all of 2^nd radial cell in dark spot; pale spot over r-m extending from M₁ to just below radius; another pale spot from dorsal portion of radius to margin of costa; r₃ with four small separated pale spots: 1^st rounded, between 2nd radial cell and M₁; 2^nd extending posterior to 2nd radial cell, abutting wing margin; 3^rd ovoid, in mid portion of cell, larger than 2^nd spot; 4^th distal pale spot close to 3^rd spot, extending to wing margin; m₁ with two pale spots, 1^st small, ovoid, beyond fork of M₁ and M₂, 2^nd larger than 1^st, not close to wing margin; m₂ with four pale spots: 1^st proximal to CuA, 2^nd and 3^rd between medial and mediocubital forks, 4^th larger, not reaching wing margin; cua₁ with a rounded pale spot in middle of cell; anal cell with faint basal sinuous pale area and one distal pale spot near mediocubital fork that is nearly subdivided, abutting wing margin; wing base with faint pale spot on M; apices of M₁, M₂ and CuA₁ broadly pale; macrotrichia sparsely distributed on distal half of wing; wing length 1.10–1.30 (1.25, n = 13) mm, breadth 0.50–0.58 (0.56, n = 12) mm; CR 0.60–0.68 (0.65, n = 13). Halter stem pale, knob brown. Legs (Fig. 2g) brown; femora with subapical, tibiae with subbasal pale bands; apex of hind tibia pale; hind tibial comb with four spines, that nearest spur longest.

Abdomen. Brown. Two subequal-size ovoid spermathecae (Fig. 2f), measuring 37.5–47.5 × 32.5–35.0 (n = 2) µm and 37.5–40.0 × 30.0–32.5 (n = 2) µm, slender sclerotized necks with 7.5 µm; third slender, elongate rudimentary spermatheca, length 27.5–30.0 (n = 2) µm.

Male. Similar to female with usual sexual differences. Sensilla coeloconica on flagellomeres 1, 6-10, one on 1, 6-8, two on 9, three on 10; AR 0.80–0.87 (0.85, n = 4). PR 1.6–2.0 (1.78, n = 4). Wing with pattern of pale spots as in Fig. 1b, wing length 0.95–1.08 (1.00, n = 4), breadth 0.35–0.40 (0.38, n = 4); CR 0.62–0.64 (0.63, n = 4). Terminalia (Fig. 3a): Tergite 9 long, tapered slightly at mid length, distal portion broader with short conical apicolateral processes, with distinct posteromedial notch; sternite 9 with rounded posteromedian excavation. Gonocoxite twice as long as broad, ventral, dorsal roots slender, elongated, sclerotized; gonostylus tapering distally, distal portion curved, apex broader with beak-like tip. Parameres (Fig. 3b) separate, each one with heavily sclerotized basal knob; stem long, curved near base, slightly sinuous, swollen on mid portion without ventral lobe; apical portion tapered, elongate, abruptly bent without lateral fringe of spicules. Aedeagus (Fig. 3a) Y-shaped; basal arms heavily sclerotized; basal arch triangular, extending 2/3 of total length; distal portion moderately slender, apex rounded.

Figure 1. 

Culicoides hildebrandoi sp. n. Wing. a Female b Male.

Figure 2. 

a–g Culicoides hildebrandoi, female sp. n. a Eye separation, anterior view b Palpal segment 3 c Mandibular teeth d Head, anterior view e Thorax, dorsal view f Spermathecae g Legs (right to left) fore-, mid- and hind.

Figure 3. 

Culicoides hildebrandoi, male terminalia sp. n. a Terminalia and aedeagus (parameres removed), ventral view b Parameres, ventral view.

Holotype female, labeled “Brazil, Rondônia, Porto Velho, Rancho Colorado Farm, 08°42'3.7"S; 63°59'3.8"W, 20.VIII.2014, CDC light trap, forest, Jansen F Medeiros col.” (CCER). Allotype male labeled as for female (CCER). Paratypes 12 females and three males: 11 females and three males same data as holotype (7 females, 2 males ILMD; 4 females, 1 male CCER); 1 female, Brazil, Amazonas, Balbina, 08.V.1985, CDC light trap, E. Castellón & S. Gomes col. (ILMD).

This is a forest species of the Amazon region of Brazil in the states of Amazonas and Rondônia.

This species is named in memory of the late Dr. Luiz Hildebrando Pereira da Silva, a parasitologist who dedicated many years to studying Tropical Diseases such as Malaria and Chagas Disease. During his long career, Dr. Hildebrando was director of the Pasteur Institute, France. In Brazil he was a Medical School Professor at the University of São Paulo and Federal University of Rondônia. He also created the Institute for Research of Tropical Pathologies in Rondônia and was pivotal for the implementation of Oswaldo Cruz Foundation in Rondônia.