Atrichopogon (Atrichopogon) rufiventris, Marino & Rossi & Cazorla, 2022

Marino, Pablo I., Rossi, Juan F. & Cazorla, Carla G., 2022, A new species of Atrichopogon (Atrichopogon) Kieffer (Diptera: Ceratopogonidae) redescription and first record from Argentina of Atrichopogon (A.) eucnemus and Atrichopogon (A.) woodfordi by Macfie, Zootaxa 5188 (6), pp. 574-586 : 579-582

Atrichopogon (Atrichopogon) rufiventris n. sp.

( Figs. 10–19 )

Diagnosis. Only extant species of Atrichopogon in the Neotropical Region without pigmented wings, and with uniformly blackish scutum and scutellum. Male: ventral portion of aedeagal-parameral complex somewhat rounded posteriorly. Female: one heavily sclerotized spermatheca with moderately narrow neck.

Male. Head ( Fig. 10 ). Dark brown. Ommatidia with interfacetal spicules, narrowly separated medially for length of 2–3 ommatidia. Antenna brown with dense well developed plume setae; flagellomeres 2–9 partially fused, 10–13 elongate; flagellomere 13 with apical nipple, not basally constricted; AR 0.91–1.25 (1.06, n = 10). Maxillary palpus ( Fig. 11 ) brown; segment 3 slender, with deep sensory pit near mid-length; segments 4–5 separate, 5 short, more slender than 4; PR 2.70–3.40 (2.98, n = 8). Head width/ mouthparts length 1.38–1.72 (1.63, n = 10). Thorax. Blackish except legs. Scutum ( Fig. 12 ) with sparse setae arising directly from surface, not in pits. Paratergite with one stout seta. Anepisternum well developed, sharply bilobed posteriorly. Legs yellowish brown; hind tibia expanded only at apex; hind tibial spur length equal to width of hind tibia at midlength; hind tibial comb with 9 spines; prothoracic TR 3.00–3.55 (3.34, n = 10), mesothoracic TR 2.83–3.67 (3.48, n = 10), metathoracic TR 2.66–3.14 (2.55, n = 10); claws curved, moderately stout; empodia present. Wing ( Fig. 13 ) plain, without pattern of pigmentation; without macrotrichiae on membrane; second radial cell 3X longer than first, first radial cell with narrow lumen; wing length 1.38–1.50 (1.43, n = 10) mm; width 0.38–0.42 (0.40, n = 10) mm; CR 0.63–0.70 (0.67, n = 10). Halter pale. Abdomen. Reddish brown. Genitalia ( Fig. 14 ): 8-9 of equal width; tergite moderately 9 short, not extending to level of apex of gonocoxite; posterior margin slightly rounded. Sternite 9 with posterior margin broadly concave, with two rows of setae, 10 setae in the first row, 6 in the second. Gonocoxite without medial lobe, 2.25X longer than greatest breadth. Gonostylus tapering gradually from base; 0.90 length of gonocoxite, slightly recurved distally, tip pointed. Aedeagal-parameral complex broad with two projections, one dorsal, triangular with blunt tip, one ventral with rounded margin, posteriorly sinuous with medial truncate tip, lateral arms stout, moderately sclerotized directed anterolaterally; basal arch extending 1/2 of total length. Cercus not extending beyond margin of tergite 9.

Female. ( Fig. 15 ). As for male, with following differences: proportions of flagellomeres as shown in Fig. 16 , flagellomeres 1–8 dark brown, slightly longer than broad, vasiform, flagellomeres 9–13 elongate, 13 longest; AR 1.36–1.76 (1.54, n = 10). Maxillary palpus ( Fig. 17 ) brown, basal 2/3 of segment 3 slightly swollen with deep sensory pit near mid-length; segments 4–5 separate, their combined lengths slightly longer than segment 3; PR 2.31–3.00 (2.74, n = 11); head width/ mouthparts length 1.28–1.43 (1.34, n = 12). Mandible poorly developed, without teeth. Thorax. Legs with hind tibial comb with 9 spines; prothoracic TR 3.18–3.89 (3.45, n = 13), mesothoracic TR 3.10–3.90 (3.34, n = 13), metathoracic TR 2.47–2.82 (2.64, n = 13); claws curved, tip not bifid. Wing ( Fig. 18 ) membrane with numerous macrotrichiae in r 3 and m 1, scarce in m 2; radial cells narrow, second 4.5X longer than first; wing length 1.24–1.46 (1.36, n = 10) mm; width 0.46–0.56 (0.51, n = 13) mm; CR 0.69–0.75 (0.71, n = 10). Abdomen ( Fig. 19 ). Segments 1–7 reddish brown, 8–10 darker. Sternite 7 subquadrangular. Sternite 8 without elongate cuticular extensions, posterior margin boat-shaped. Sternite 9 rectangular, laterally sclerotized. Genital sclerotization open, anterior margin rounded. Spermatheca dark brown, ovoid, measuring 100–116 (114, n = 13) by 70–90 (86, n = 13) µm, with narrow neck, measuring 14 (n = 13) µm. Cercus pale.

Distribution and bionomics. Atrichopogon rufiventris n. sp. is known from Buenos Aires province, Argentina: from the southwest in Sierra de la Ventana and from the northeast, in the grassland area of the Reserva Natural Integral de Punta Lara, and also in two areas within the Reserva Costera Municipal de Avellaneda, the gallery forest and the vineyards.

Type material. Holotype male on slide, labeled: “ HOLOTYPE Atrichopogon rufiventris Marino and Rossi , Argentina, Buenos Aires, Reserva Costera Municipal de Avellaneda , 5-XII-2019, J. Rossi, sweep net ” ( MLPA); allotype female on slide, labeled as for holotype . Paratypes, 15 males, 17 females, as follows: same data as holotype , 1 male, 2 females ( MLPA); same locality, 19-XII-2019 , 2 males, 2 females, J. Rossi, sweep net ( MLPA); same locality, 9-III-2021 , 1 male, 3 females J. Rossi, sweep net ( MLPA); same locality, 23-III-2021 , 3 females, J. Rossi, sweep net ( MLPA); same locality, 20-IV-2021 , 1 male, J. Rossi, sweep net ( MLPA); 27-IV-2021 , 1 female, J. Rossi, sweep net ( MLPA); same locality, 4-V-2021 , 2 males, 1 female, J. Rossi, sweep net ( MLPA); Reserva Natural Integral Punta Lara (Coronillo), 7/ 14-XII-2016 , 1 male, 1 female, C. Cazorla, Malaise trap, ( MLPA); same data except 34º 47’ 18”S; 58º 00’ 01” W, marginal forest,10/ 11-XI-2014 , 1 male, Cazorla-Campos, CDC light trap; same data except 9/ 10-XII-2014 , 1 male; same data except 7/ 8-I-2015 , 1 male, 1 female; Sierra de la Ventana, Reserva provincial Tornquist, arroyo “de la clausura” 38º 02’ 46.1”S; 61º 59’ 10.1” W, 16-XI-2006, 1 male, Cazorla-Marino, sweep net ( MLPA); same data except 21-XII-2006 , 1 male, 2 females; same data except 7-II-2007 , 2 males, 1 female, Marino- Cazorla ( MLPA) .

Taxonomic discussion. Males and females of Atrichopogon rufiventris n. sp. were associated by their reddish brown abdominal coloration observed in ethanol 70%, and the scutum and scutellum uniformly blackish. This new species is very similar to the Patagonian species A. obfuscatus Ingram & Macfie , and A. seudoobfuscatus Spinelli from Buenos Aires province. The male genitalia of these three species are very similar, however in A. obfuscatus and A. seudoobfuscatus the posterior margin of sternite 9 is deeply concave and the tergite 9 is moderately elongated. Females of these two species differ from those of A. rufiventris by their large mandibular teeth, and their legs, halter and cercus are brown. In addition, the female of A. seudoobfuscatus has bare eyes, a distinctive pattern of pigmentation on their scutum and larger spermathecae.

Derivation of specific epithet. The specific name rufiventris refers to the reddish-brown coloration of the abdominal segments observed in freshly collected specimens.

Figures

FIGURES 10–14. Atrichopogon rufiventris n sp. Holotype male, 10–14. 10 head. 11 maxillary palpus. 12 scutum and scutellum. 13 wing. 14 genitalia. Scale bars: 0.1 mm.

FIGURES 15–19. Atrichopogon rufiventris n sp. Allotype female, 15–19. 15 habitus. 16 head. 17 maxillary palpus. 18 wing. 19 tip of abdomen, ventral view. Scale bars: 0.1 mm.