Dasyhelea recurva, Grogan & Díaz & Spinelli & Ronderos, 2019

Grogan, William L., Díaz, Florentina, Spinelli, Gustavo R. & Ronderos, Maria M., 2019, The Biting Midges of the Caribbean island Curaçao (Diptera: Ceratopogonidae) I. Species in the genus Dasyhelea Kieffer, Zootaxa 4700 (3), pp. 301-325 : 310-311

Dasyhelea recurva n. sp.

(Figs. 6–10, 55–57)

Diagnosis. The only Neotropical species of the mutabilis group with the following combination of characters. Males aedeagus heavily sclerotized with broad, stout basal arms, and slender posterolateral arms with recurved, bifid apices; gonocoxal apodemes and paramere asymmetrical, the right gonocoxal apodeme slender and narrowly fused to paramere, the left gonocoxal apodeme stout and broadly fused to paramere. Female unknown.

Male. Head (Fig. 6). Dark brown. Eyes contiguous, the distance of contiguity not discernible in holotype, the only known specimen. Antennal flagellum dark brown; flagellomeres 2–9 rhomboidal, 10–13 elongate, only 10–13 sculptured; flagellomeres 2–10 with whorl of long sensillae chaetica comprising the moderately dense plume; antennal ratio 0.95; flagellum length 0.45 mm. Frontal sclerite elliptical, with slender moderately long, pointed, ventral projection. Clypeus with 5 pairs of setae. Palpus (Fig. 7) brown; segment 3 as long as 4+5 combined with 1–2 capitate sensillae on distal 1/4 of mesal surface; palpal ratio 3.60. Thorax (Fig. 8). Dark brown; scutellum with 6 large setae. Femora, tibiae dark brown, tarsi light brown, tarsomeres 5 infuscated; hind tibial comb with 6 spines; prothoracic tarsal ratio 1.91, mesothoracic tarsal ratio 2.25, metathoracic tarsal ratio 2.21. Wing (Fig. 9) membrane hyaline with moderately dense macrotrichiae; radial cells without lumen, 2 nd radial cell very short; apices of costa, radius at perpendicular angle with wing margin; fork of CuA 1 distad to level of apex of 2 nd radial cell; anal lobe moderately developed; wing length 0.62 mm, width 0.20 mm; costal ratio 0.44. Halter dark brown. Abdomen. Dark brown. Genitalia (Figs. 10, 55–57). Tergite 9 tapering gradually distally to rounded apex that extends to or near apices of gonocoxites; apicolateral processes parallel, slender, elongate with 1 medium-sized apical seta; cercus very small, located at base of apicolateral process with 4 setae, the 2 mesal medium-sized, external ones longer. Sternite 9 (Figs. 10, 55) 0.42 length of greatest width; anterior margin nearly straight; posterior portion tapered with broad, rounded apex that extends nearly to basal arch of aedeagus. Gonocoxite stout, 1.7 x longer than broad with 10–12 large setae on apicomesal surface and a slender baso-mesal tubercle; gonostylus as long as gonocoxite, distal portion slightly curved, tapering gradually distally with broader apex and pointed tip. Gonocoxal apodemes and paramere (Figs. 10, 56) asymmetrical; distal-most sections of gonocoxal apodemes broad, foot-shaped, apices rounded; right apodeme nearly straight, proximal portion slender, narrowly fused to paramere; left apodeme much broader than right, proximal portion broadly fused to paramere; paramere moderately stout basally, tapering slightly distally, apex apparently obliquely truncate. Aedeagus (Figs. 10, 57) heavily sclerotized, 0.55 length of greatest width; basal arch concave, extending 0.20 of total length of aedeagus; basal arms short, stout, apices tapered, recurved 60°; medio-posterior margin with 2 short, conical, apicolateral teeth; posterolateral arms convergent proximally, with abruptly recurved apical sections and bifid tips; posteromedian projection short, very lightly sclerotized, with blunt apex.

Female. Unknown.

Distribution. Curaçao.

Type material. Holotype male, labeled “ Curaçao, Christoffel Nat. Pk., Christoffelberg , trailhead parking, 12°20ʹ40.63ʹʹ N, 69°67ʹ11.38ʹʹ W, 9-XI-2014, M. C. Thomas, BL trap ” (deposited in FSCA).

Derivation of specific epithet. The specific name is a combination of two Latin terms, re (back, again) and curv (curved), a reference to the distinctive recurved apices of the posterolateral arms of the aedeagus.

Discussion. At least two other primarily tropical New World species of Dasyhelea have aedeagal posterolateral arms with recurved apices: D. borgmeieri Wirth & Waugh (1976) , that was originally described from Brazil, Grenada, Panama and Trinidad (type locality), then subsequently recorded from the Galápagos Islands ( Ecuador) by Borkent (1991), and it was recently discovered in the USA from Florida (WLG; personal observations) and also from Belize (WLG; in FSCA); and, D. cacaoi Wirth & Waugh (1976) that is known only from Panama and Trinidad (type locality). The males of these two species differ from D. recurva n. sp. in having less massive aedeagi with apically pointed posterolateral arms, sternite 9 that extends just beyond the basal arch ( D. borgmeieri ) or, is very elongate, tapered and extends more than 1/2 the length of the posterolateral arms ( D. cacaoi ). Males of D. borgmeieri further differ from D. recurva n. sp. in having symmetrical gonocoxal apodemes and a short slender paramere, a greatly curved gonostylus and tergite 9 with very short apicolateral processes. Males of D. cacaoi also differ from D. recurva n. sp. in having more elongate gonocoxites, a longer tergite 9 with a convex apical margin and a longer, slender paramere with pointed curved apex.

In addition, this species is also similar to D. curacaoensis n. sp., but the latter species differs from D. recurva in having a very short antennal flagellum, longer gonocoxites, shorter nearly straight gonostyli, a much broader tergite 9, and a longer paramere with curved, J-shaped apical section, and, aedeagus with straight, tapered posterolateral arms with pointed apices.