Culicoides (Haematomyidium) dellapei Spinelli, Ronderos & Díaz, 2021

Spinelli, Gustavo R., Ronderos, Maria M. & Díaz, Florentina, 2021, Two new species and new records of Neotropical Culicoides Latreille (Diptera: Ceratopogonidae), Zootaxa 4915 (3), pp. 401-410 : 404-406

Culicoides (Haematomyidium) dellapei Spinelli, Ronderos & Díaz n. sp.

( Figs. 7–12 )

Diagnosis. The only Neotropical species of the subgenus C. (Haematomyidium Goeldi) with the following combination of characters: females with flagellomeres 4–12 subequal in length; sensilla coeloconica on flagellomeres 1, 6–8; palpal segment 3 slender, slightly swollen on distal 1/3, with subapical pit; poststigmatic pale spots in r 3 fused in an oblique double spot; cell m 1 with two pale spots, distal one well separated from wing margin; cell m 2 with pale spot posterior to medial fork, without pale spot anterior to cubital fork; macrotrichia sparse on distal third of cells r 3 and m 1, only few at extreme apical margin in m 2, cua 1 and anal cell, absent in base of m 2. Male unknown.

Female. Head ( Fig. 7 ) dark brown. Eyes bare, separated by distance slightly shorther than the length of one ommatidia. Flagellum brown; flagellomeres 4–8 slightly longer than 9–12, 13 longest; AR 0.76; sensilla coeloconica on flagellomeres 1, 6–8. Palpus ( Fig. 8 ) brown, segment 3 slender, slightly swollen on distal 1/3, with moderately deep subapical pit opening by rounded pore; PR 2.60; P/H ratio 0.82. Mandible with 15 teeth.

Thorax ( Fig. 9 ). Uniformly dark brown; scutellum with 4 large, 8 small setae. Legs dark brown; tibiae with subbasal pale rings, broad apex of hind tibia pale, fore and midfemora with subapical pale rings; hind tibial comb with four spines, second from spur longest. Wing ( Fig. 10 ) length 0.90 mm; width 0.42 mm; CR 0.57; second radial cell, distal half of first radial cell in dark spot; pale spot over r-m cross vein abutting wing margin; two poststigmatic pale spots in r 3 fused as oblique double spot; distal pale spot in r 3 transverse, not abutting anterior wing margin; m 1 with two oval pale spots, distal one well separated from wing margin; m 2 with elongate pale spot posterior to medial fork, rounded pale spot narrowly separated from wing margin in apex of cell, no trace of pale spot anterior to cubital fork; cua 1 with rounded pale spot narrowly separated from wing margin; anal cell with one distal pale spot. Macrotrichia sparse on distal third of r 3 and m 1, only few at extreme margin in m 2, cua 1 and anal cell, absent in base of m 2. Halter brownish, apex of knob whitish.

Abdomen ( Fig. 11 ). Dark brown. Two slightly unequal spermathecae with broad, straight, moderately long necks ( Fig. 12 ), measuring 54 by 40 μm and 48 by 37 μm, necks 6 μm; rudimentary third, ring present.

Male. Unknown.

Type data and depository. “ Holotype female, Argentina, Buenos Aires, Tandil , 19-II-19-III-2006, P. Dellapé, at light” ( MLPA) .

Distribution. Argentina, known only from the type-locality, in a backyard of a house in a periurban area of Tandil city in southeastern Buenos Aires province. The city is located in the Tandil sierras, forming part of the Tandilia orographic system (maximum height 534 above sea level). The dominant vegetation is the grass steppe, among which numerous herbaceous species grow ( Dellapé & Carpintero 2012).

Etymology. We are pleased to name this species after its collector, Dr. Pablo Dellapé, entomologist at the Museo de La Plata.

Taxonomic discussion. This species belongs to the subgenus C. (Haematomyidium), that includes small species with dark brown scutum, rarely with prominent pattern. The females of this subgenus can be recognized by the sensilla coeloconica on flagellomeres 1, 5–8 or 1, 6–8; wing with second radial cell included in a very dark spot, the cell r 3 with 3 or 4 small pale spots, the 2 poststigmatic pale spots sometimes fused, the subapical pale spot in cell r 3 usually transverse, not attaining wing margin, the cell m 2 with only one or two pale spot distal to level of cubital fork; one pale spot in apex of anal cell, apices of veins dark; and 2 functional spermathecae present.

This new species is very similar to Culicoides crucifer by virtue of the similar wing pattern and by the slender palpus. However, in the latter species the third palpal segment is distinctly longer (palpal ratio 3.54 in the holotype, 3.34 in the specimen of C. crucifer recorded below), the poststigmatic pale spots are clearly separated, and the macrotrichia cover the distal half of the wing, including cells m 2 to its base, cua 1 and anal cell.

The widely distributed species Culicoides debilipalpis Lutz, 1913 also has a very similar wing pattern, but in this species the macrotrichia is much more abundant, extending in two rows to base of cell m 2, the eyes are pilose and the spermathecae necks are longer.

Figures

FIGURES 7–12. Culicoides dellapei n. sp. Holotype female, 7–12. 7 head. 8 palpus. 9 legs. 10 wing. 11 abdomen. 12 detail of spermathecae. Scale bars = 0.05 mm.