Dasyhelea quadrifurca, 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 : 213-216

Dasyhelea quadrifurca new species

( Figs. 5–6 )

Diagnosis. The only Neotropical species of the grisea group with males having an aedeagus with a four-pronged fork-like distal portion, a broad heart-shaped frontal sclerite, and moderately long cylindrical apicolateral processes with 1–2 apical setae. Female unknown.

Male. Head ( Fig. 5 A). Dark brown. Eyes contiguous for a distance equal to the width of 3–4 ommatidia. Frontal sclerite ( Fig. 5 B) broad, heart-shaped, with long, slender ventral projection that extends to dorsum of clypeus. Antennal flagellum dark brown; flagellomeres 2–9 rhomboid, 10–13 elongate, 13 longest; flagellomeres 2–10 with whorl of long sensilla chaetica that comprise the dense plume that extends to apex of flagellomere 12; antennal ratio 0.96. Clypeus with 11 pairs of setae. Palpus ( Fig. 5 C) brown; segment 3 short, with 1–2 capitate sensilla on distolateral surface; palpal ratio 2.50. Thorax. Scutum dark brown; scutellum slightly paler with 9 large, 5 smaller setae. Legs brown, tarsi paler except tarsomeres 5 infuscated; hind tibial comb with 7 spines; prothoracic tarsal ratio 2.13, mesothoracic tarsal ratio 2.47, metathoracic tarsal ratio 2.16. Wing ( Fig. 5 D) membrane hyaline, covered with dense macrotrichia; 2nd radial cell well developed; apices of costa, radius at slight oblique angle; fork of CuA1 anterior to level of base of 2nd radial cell; anal lobe well developed; wing length 1.22 mm, width 0.42 mm; costal ratio 0.50. Halter brownish. Abdomen. Dark brown. Genitalia ( Figs. 5 E, 6A). Tergite 9 with broad, rounded caudal margin that extends beyond apices of gonocoxites; apicolateral process slender, elongate, with 1–2 moderately long apical setae; cercus conspicuous, located just anterior of base of apicolateral process, with 4–6 thin setae. Sternite 9 ( Figs. 5 E, 6B) 0.33 length of greatest width, tapered abruptly distally, posteromedian margin narrow with shallow excavation. Gonocoxite stout, 1.43 x longer than greatest width, broadest at mid-portion with short, mesal process; gonostylus as long as gonocoxite, nearly straight, proximal 1/3 moderately broad, distal 2/3 slightly tapered, apex slightly broadened, bluntly rounded. Gonocoxal apodemes and paramere ( Figs. 5 E, 6C) forming an asymmetrical structure; proximal portions of gonocoxal apodemes stout, recurved; right apodeme 0.60 length of left apodeme, broadly contacting paramere; left apodeme with slender, straight distal portion, tapering slightly distally to pointed tip that does not contact paramere; paramere slender basally, broader mesally, distal portion curved at base nearly 90°, tapering to pointed tip. Aedeagus ( Figs. 5 E, 6D) nearly 0.80 length of greatest width; basal arch heavily sclerotized, extending 0.25 of total length; basal arms slender distally, apex recurved; posterolateral arms with inner straight, sub-parallel portions with rounded tips, and stout, straight outer portion with pointed tip that extend 3/4 length of inner posterolateral arm.

Female. Unknown.

Distribution. Guadeloupe.

Type material. Holotype male labeled “ Guadeloupe, Basse Terre , Pointe a Lezard, 17-V-2012, R. H. Turnbow, BL trap ” (deposited in FSCA).

Derivation of specific epithet. The specific epithet is from the Latin, quadri (four) and furca (fork), in reference to the four-pronged fork-like distal portion of the male aedeagus.

Discussion. The holotype male of this new species is similar to males of three primarily Nearctic species: D. griseola Wirth , D. pseudoincisurata and D. stemlerae Waugh & Wirth (1976) in that its posteromedian margin of sternite 9 has a shallow excavation and aedeagal posterolateral arms bearing an outer process. However, males of D. griseola differ from this new species by their very short apicolateral processes, the hyaline outer process of the aedeagal posterolateral arms are mesally recurved, and their wing has a longer costa (costal ratio 0.57). Males of D. pseudoincisurata also differ from this new species by their straight distal margin of tergite 9 with longer greatly divergent apicolateral processes, outer aedeagal posterolateral arms have broader tips, and the tip of their gonostylus is usually notched. Finally, males of D. stemlerae differ from this new species by their tergite 9 with a much narrower truncate apex and the inner and outer processes of their aedeagal posterolateral arms are of nearly equal length.

Figures

FIGURE 5. Dasyhelea quadrifurca n. sp. Holotype male. A. head. B. frontal sclerite. C. palpus. D. wing. E. genitalia.

FIGURE 6. Dasyhelea quadrifurca n. sp. Holotype male. A. genitalia. B. sternite 9. C. gonocoxal apodemes and paramere. D. aedeagus. Scale bar: 0.05 mm.