Dasyhelea brachystyla, Grogan, Willliam L., Díaz, Florentina, Spinelli, Gustavo R. & Ronderos, Maria M., 2016

Grogan, Willliam L., Díaz, Florentina, Spinelli, Gustavo R. & Ronderos, Maria M., 2016, The biting and predaceous midges of Guadeloupe (Diptera: Ceratopogonidae). II. Species of the subfamily Dasyheleinae, Zootaxa 4184 (2), pp. 201-254 : 241-243

Dasyhelea brachystyla new species

( Figs. 23–24 )

Diagnosis. The only Neotropical species of Dasyhelea in the mutabilis group with a very short, stout gonostylus with an abruptly tapered apex and sharply pointed tip, gonocoxal apodemes and paramere fused, forming a symmetrical structure, paramere moderately slender and extends beyond apex of aedeagus, and an aedeagus with a very broad basal arch and convergent or overlapping posterolateral arms. Female unknown.

Male. Head ( Fig. 23 A). Dark brown. Eyes contiguous for a distance equal to the width of 3 ommatidia. Frontal sclerite elliptical, moderately slender with slender posterior projection that extends to base of clypeus. Antennal flagellum dark brown; flagellomeres 2–9 rhomboidal, 10–13 elongate, only 11–13 sculptured; flagellomeres 2–10 with whorl of long sensilla chaetica comprising the moderately dense plume that extends to or beyond base of flagellomere 13; antennal ratio 0.84–1.05 (0.97, n=8). Clypeus ( Fig. 23 B) with 7 pairs of setae. Palpus ( Fig. 23 B) brown; segment 3 moderately long, slightly longer than 4+5 combined with 1 capitate sensilla on distal external surface; PR 3.86–4.37 (4.11, n=8). Thorax. Scutum dark brown; scutellum golden brown with 6 large, 3 smaller setae. Femora, tibiae dark brown, tarsi paler except tarsomeres 5 infuscated; hind tibial comb with 7 spines; prothoracic tarsal ratio 1.83–2.00 (1.90, n=8), mesothoracic tarsal ratio 1.85–2.14 (1.98, n=7), metathoracic tarsal ratio 1.90–2.08 (1.97, n=8). Wing ( Fig. 23 C) membrane hyaline with moderately dense macrotrichia on distal 2/3; 2nd radial cell very short with tiny lumen; apices of costa, radius at perpendicular angle with wing margin; fork of CuA1 at level of apex of 2nd radial cell; wing length 0.82–0.90 (0.87, n=7) mm, width 0.30–0.34 (0.31, n=7) mm; costal ratio 0.46–0.51 (0.48, n=7). Halter brown. Abdomen. Dark brown. Genitalia ( Figs. 23 D, 24A). Tergite 9 tapering gradually distally, apex truncate, extending beyond apices of gonocoxites; apicolateral process slender, elongate with large apical seta; cercus very small, short, located near base of apicolateral process with 3 small setae. Sternite 9 ( Figs. 23 D, 24B) 0.43 length of greatest width; anterior margin nearly straight; posterior portion elongate, heavily sclerotized with short, hyaline, slightly notched apical projection. Gonocoxite straight, stout, twice as long as broad, with a few large setae on apicomesal side; gonostylus broad, very short, 0.56 length of gonocoxite, distal portion abruptly tapered with narrowed apex and pointed tip. Gonocoxal apodemes and paramere ( Figs. 23 D, 24C) forming a symmetrical structure; proximal portions of gonocoxal apodemes moderately stout, recurved over 90º with narrow pointed apex, distal portions curved, slender, fused with the base of the moderately slender paramere that extends beyond apex of aedeagus, tip rounded. Aedeagus ( Figs. 23 D, 24D) broad, 0.60 length of greatest width; basal arch heavily sclerotized, shallow, concave, extending 0.14 of total length of aedeagus; basal arm moderately slender, nearly straight, laterally directed; posterolateral arms heavily sclerotized, slender, curved distally, apices convergent or overlapping, extending over distal portion of posteromedian projection, tips pointed; posteromedian projection apparently conical, mesally swollen, apical portion extending beyond posterolateral projections, tip slightly truncate, folded ventrally.

Female. Unknown.

Distribution. Guadeloupe.

Type material. Holotype male labeled “ Guadeloupe, Basse Terre, NE Pigeon (16.14404º N, 61.74977º W), 18-V-2012, RH Turnbow, BL trap ” (deposited in FSCA) . Paratypes 7 males, as follow: same data as holotype except 23-V-2012 , 2 males; same data except Trace des Cretes (D-14), 22-V-2012 , 4 males; same data except 3.2 km E of Mahault , 24-V-2012 , 1 male.

Derivation of specific epithet. The specific epithet is a combination of two Greek terms, brachy (short) and styl (a pointed instrument), in reference to the unusually short gonostyli of males of this new species.

Discussion. Males of Dasyhelea brachystyla differ from males of all other Neotropical species of Dasyhelea in the mutabilis group by their peculiar short, stout gonostylus, symmetrical gonocoxal apodemes and paramere, and the broad complex aedeagus with slender posterolateral arms that extend over the distal portion, the apex of which is truncate and folded ventrally.

Figures

FIGURE 23. Dasyhelea brachystyla n. sp. Holotype male. A. head. B. palpus. C. wing. D. genitalia.

FIGURE 24. Dasyhelea brachystyla n. sp. Holotype male. A. genitalia. B. sternite 9. C. gonocoxal apodemes and paramere. D. aedeagus. Scale bar: 0.05 mm.