Dasyhelea spatula, 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 : 216-219

Dasyhelea spatula new species

( Figs. 7–8 )

Diagnosis. The only Neotropical species in the grisea group with male tergite 9 having an elongate, quadrangular distal portion that extends well beyond apices of gonocoxites and short, triangular, slightly divergent apicolateral processes; and distal portion of the paramere flat, triangular, greatly expanded, spatula-shaped with recurved tip. Females with slender, elongate anterior portion of subgenital plate, and posterior portion with U-shaped excavation; and an ovoid spermatheca with a stout, elongate, greatly recurved neck.

Male. Head ( Fig. 7 A). Brown. Eyes contiguous for a distance equal to the width of 4 ommatidia. Frontal sclerite broad, slightly bilobed. Antennal flagellum dark brown; flagellomeres 2–9 rhomboidal, 10–13 elongate, 11 or 13 longest; flagellomeres 2–10 with whorl of long sensilla chaetica that form the dense plume that extends to base of flagellomere 13; antennal ratio 0.93. Clypeus ( Fig. 7 B) with 6 pairs of setae. Palpus ( Fig. 7 C) light brown; segment 3 moderately short, slightly bulbous with scattered capitate sensilla; palpal ratio 2.27. Thorax. Scutum dark brown; scutellum with 8 large, 3 smaller setae. Wing ( Fig. 7 D) slender; membrane hyaline, covered with dense macrotrichia; 2nd radial cell narrow; apex of costa, radius at slight oblique angle; fork of CuA1 at level just anterior to base of 2nd radial cell; anal lobe well developed; wing length 1.04 mm, width 0.36 mm; costal ratio 0.52.

Abdomen. Dark brown. Genitalia ( Figs. 7 E, 8A). Tergite 9 tapering progressively distally to apices of gonocoxites, with an elongate quadrangular distal portion that extends considerably beyond gonocoxites, with short, triangular, slightly divergent apicolateral processes with 1 small apical seta; cercus small, located anterior to apicolateral process with several short setae. Sternite 9 ( Figs. 7 E, 8B) 1/3 length of greatest width; anterior margin curved, convex; posteromedian portion slightly elongated with short cap-like process that extends onto posterior margin of basal arch of aedeagus. Gonocoxite moderately short, 1.50 x longer than greatest width; gonostylus slightly longer than gonocoxite, pilose, nearly straight, proximal 1/4 with short mesal lobe near terminus of tapered section, apex bluntly rounded. Gonocoxal apodemes and paramere ( Figs. 7 E, 8C) forming an asymmetrical structure; proximal portion of gonocoxal apodemes broad, with recurved extreme base; right apodeme with tapered, slightly sinuate distal portion, the slender pointed apex of which narrowly contacts paramere; left apodeme with moderately slender distal portion, with truncate apex that does not contact paramere; paramere slender basally, broader mesally, distal portion recurved ventrolaterally, apex broad, spatulate with recurved tip. Aedeagus ( Figs. 7 E, 8D) heavily sclerotized, 0.60 length of greatest width; basal arch very low, extending only 0.10 of total length; basal arm broad, apex narrowed, recurved nearly 180º; posterolateral arms stout, slightly convergent with blunt apices, each with serrate inner margin.

Female. Head ( Fig. 7 F). Brown. Eyes contiguous for a distance equal to the width of 4 ommatidia. Frontal sclerite broad, slightly bilobed, with long, slender ventral projection. Antennal flagellum dark brown; flagellomeres 2–8 vasiform, 9–13 becoming gradually more elongate, 13 longest; antennal ratio 0.87. Clypeus with 5 pairs of setae. Palpus ( Fig. 7 G) light brown, short; segment 3 moderately short with 2 capitate sensillae on mesal surface; palpal ratio 2.09. Thorax. Scutum brown, humeral areas and prescutellar depression paler; scutellum slightly paler with 8 large, 2 smaller setae. Legs pale brown; hind femur with mesal dark spot; femorotibial joints dark; tarsomeres 5 infuscated; hind tibial comb with 6 spines; prothoracic tarsal ratio 2.36, mesothoracic tarsal ratio 2.07, metathoracic tarsal ratio 2.40. Wing ( Fig. 7 H) moderately broad; membrane hyaline, covered with dense macrotrichia; 2nd radial reduced to a short suture; apex of costa, radius at oblique angle; fork of CuA1 at level anterior to base of 2nd radial cell; anal lobe well developed, broad; wing length 0.98 mm, width 0.44 mm; costal ratio 0.51. Halter pale. Abdomen ( Fig. 7 I). Brown. Subgenital plate moderately sclerotized; anterior portion slender, elongate; posterior portion stout, with U-shaped median excavation; posterolateral arms more heavily sclerotized, bases connected by slender sclerite. Spermatheca ovoid, length/width 68 x 60 µm, with stout greatly elongate neck that is recurved nearly 180º and narrowly separated from spermatheca, length 50 µm.

Distribution. Guadeloupe.

Type material. Holotype male, allotype female labeled “ Guadeloupe, Basse Terre , Trace des Cretes (D-14), 22-V-2012, R. H. Turnbow, BL trap ” (deposited in FSCA) .

Derivation of specific epithet. The species epithet is a reference to the broad, triangular, spatulate distal portion of the male paramere.

Discussion. The aedeagus of the holotype male of D. spatula has serrate inner margins of the posterolateral arms that are similar to those of D. hamula n. sp. However, the holotype male of that species differs from this new species in having a slender distal portion of the paramere with a subapical sharply pointed tubercle and a short, recurved apex. The subgenital plate and spermatheca of the allotype female of D. spatula is similar to females of D. pseudoincisurata , but the latter species is larger (wing length 1.20–1.47 mm), the distal portion of the subgenital plate is extremely slender and the neck of its spermatheca is tapered and not nearly as recurved as in this new species.

Figures

FIGURE 7. Dasyhelea spatula n. sp. Holotype male, A – E, Allotype female, F – I. A, F. head. B, G. clypeus. C, G. palpus. D, H. wing. E. genitalia. I. subgenital plate and spermatheca.

FIGURE 8. Dasyhelea spatula n. sp. Holotype male. A. genitalia. B. sternite 9. C. gonocoxal apodemes and paramere. D. aedeagus. Scale bar: 0.05 mm.