Dasyhelea nelidae, 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 : 244-247

Dasyhelea nelidae new species

( Figs. 25–26 )

Diagnosis. The only Neotropical species of the fasciigera complex with males having an elongate sub-triangular sternite 9 with a greatly tapered distal portion with irregular margins and slender apex, an inner gonostylus with a short subapical prong and an aedeagus covered with a thin hyaline envelope. Females have an infuscated wing membrane, a small (length 34 µm) ovoid spermatheca with a short broad neck, and a subgenital plate with a circular, lightly sclerotized anterior portion, a slightly rectangular heavily sclerotized posterior portion and a small lumen.

Male. Head ( Fig. 25 A). Dark brown. Eyes contiguous for a distance equal to width of 3 ommatidia. Frontal sclerite rhomboid with slender ventral projection extending to base of clypeus. Antennal flagellum 2–9 rhomboid with flagellomeres 9–13 elongate, 13 broad, much shorter than 9–12; flagellomeres 2–10 with whorl of long sensilla chaetica forming the dense plume that extends to or beyond base of flagellomere 13; antennal ratio 0.84– 0.94 (0.88, n=7). Palpus ( Fig. 25 B) light brown; segment 3 moderately long with scattered mesal capitate sensilla; palpal ratio 3.28–3.42 (3.36, n=5). Thorax. Dark brown. Scutellum golden brown with 6 large, 1 smaller setae. Prothoracic tarsal ratio 2.17–2.35 (2.47, n=6), mesothoracic tarsal ratio 2.68–2.70 (2.74, n=6), metathoracic tarsal ratio 2.21–2.38 (2.32, n=6). Wing ( Fig. 25 C) slender; membrane slightly infuscated with dense macrotrichia; veins dark brown; 2nd radial cell moderately well developed; junction of costa, radius forming a poorly developed acute angle; fork of CuA1 at level just beyond apex of costa, radius; wing length 0.80–0.88 (0.84, n=5) mm, width 0.26– 0.30 (0.28, n=5) mm; costal ratio 0.45–0.47 (0.46, n=5). Genitalia ( Figs. 25 D, 26A). Tergite 9 tapering gradually distally to moderately broad, truncate apex that extends to or beyond apices of gonocoxites; apicolateral process heavily sclerotized, elongate, cylindrical with moderately short apical seta; cercus apparently represented by 2 shorter lobes arising from basal portion of apicolateral process with short apical setae. Sternite 9 ( Figs. 25 D, 26B) 0.50 length of greatest width; distal portion sub-triangular, greatly tapered with irregular margins and slender apex. Gonocoxite straight, stout, 1.55 x longer than greatest width; distal 2/3 becoming increasingly broader, with subapicomesal pointed triangular process, distal margin rounded. Gonostylus ( Fig 26 C) bifurcate; outer gonostylus broad on proximal 1/4, distal portion slightly curved, slender with pointed apex; inner gonostylus half as long as outer gonostylus, proximal 2/3 broad, distal 1/3 tapered, curved, distal portion slender with short subapical prong and sharply pointed tip. Gonocoxal apodemes and paramere ( Figs. 25 D, 26D) in form of asymmetrical structure; gonocoxal apodemes heavily sclerotized, right apodeme short, curved, broadly fused to paramere, left apodeme much longer, basal portion moderately broad, recurved, distal portion slender, slightly sinuate, extreme apical section narrowly fused to paramere; paramere broad proximally, distal portion curved, slightly tapered with acute, pointed tip. Aedeagus ( Figs. 25 D, 26E) 0.50 length of greatest width, covered with thin hyaline envelope which extends from near apices of basal arms to apex of sternite 9; basal arch heavily sclerotized, moderately shallow, extending 0.33 of total aedeagus length, distal margin dentate; basal arm slender, slightly recurved; posterolateral arm heavily sclerotized, apically divided, each half crossing each other.

Female. Head ( Fig. 25 E). Dark brown. Eyes contiguous for a distance equal to the width of 2 ommatidia. Antennal flagellum with flagellomeres 2–13 vasiform, 9–13 slightly longer than 2–8; antennal ratio 0.65–0.76 (0.70, n=2). Clypeus ( Fig. 25 F) with broad, detached wing-like proximal portion; distal portion narrow with 4 pairs of setae. Palpus ( Fig. 25 G) pale brown; segment 3 moderately short with 3–4 capitate sensillae on proximal 2/3 of mesal surface; palpal ratio 2.87 (n=3). Thorax. Scutum dark brown; scutellum paler with 6 large, 2 smaller setae. Femora, tibiae dark brown, tarsi slightly paler; hind tibial comb with 5 spines; prothoracic tarsal ratio 2.00–2.22 (2.07, n=3), mesothoracic tarsal ratio 2.22–2.55 (2.39, n=3), metathoracic tarsal ratio 2.08–2.09 (2.08, n=3). Wing ( Fig. 25 H) moderately broad; membrane infuscated, covered with dense macrotrichia except for a narrow area posterior of radial cells; veins dark brown; 2nd radial cell reduced to a short suture; fork of CuA1 at level of apex of costa, radius; anal lobe moderately well developed; wing length 0.70–0.74 (0.72, n=3) mm, width 0.30–0.32 (0.31, n=3) mm; costal ratio 0.42–0.46 (0.44, n=3). Halter dark brown. Abdomen ( Fig. 25 I). Dark brown. Subgenital plate with a circular, lightly sclerotized anterior portion, a slightly rectangular heavily sclerotized posterior portion and a small lumen; posterior margin straight; posterolateral arms slender, recurved. Spermatheca small (34 x 26 µm), ovoid, heavily sclerotized, neck short, length 4 µm.

Distribution. Guadeloupe.

Type material. Holotype male labeled “ Guadeloupe, Basse Terre, NE Pigeon (16.14404º N, 61.74977 º W), 18-V-2012, RH Turnbow, BL trap ” (deposited in FSCA) ; allotype female same data as holotype except 23-V-2012 . Paratypes 6 males, 3 females, as follows: same data as holotype , 3 males, 1 female; same data except 17-V-2012 , 1 male; same data as allotype 3 males , 1 female; same data except Pointe a Lezard, 17-V-2012 , 1 female. Derivation of specific epithet. This species is named after Mrs. Nélida Caligaris, artistic technician of the División Entomología, Museo de La Plata.

Discussion. This new species is a member of the Dasyhelea fasciigera complex as defined by Remm (1962) and Borkent & Forster (1986), which Dominiak (2012) included in the subgenus Pseudoculicoides (= mutabilis group). Males in the Fasciigera complex differ from males of all other species in the mutabilis group by their bifurcate gonostyli. This complex is composed of the following six species that inhabit the Americas ( Borkent & Forster 1986; Dominiak & Szadziewski 2010; Dominiak 2012): Dasyhelea bifida Zilahi-Sebess (1936) , D. crassiseta Borkent & Forster , D. fasciigera Kieffer (1925b) , D. furva Remm (1967) , D. pollex Borkent & Forster , and D. tristyla Wirth. Males of D. bifida differ from this new species by their triangular tergite 9 with a pointed tip and their bifurcate aedeagal posterolateral arms. Males of D. crassiseta differ from this new species by their inner gonostylus that is as long as the outer gonostylus and the paramere is produced beyond the aedeagus. Males of D. fasciigera differ from this new species by their tergite 9 with a deeply notched distal margin and their single aedeagal posterolateral arms that are stout with blunt tips. Males of D. pollex differ from this new species by their trefoil-shaped tergite 9 and their bifurcate aedeagal posterolateral arms. Males of D. tristyla differ from this new species by their U-shaped inner gonostylus and their bifurcate aedeagal posterolateral arms, each of which is recurved ventrolaterally.

It is likely that Dasyhelea pumila Macfie (1939) , which is known only from Santa Catarina, Brazil, is also a member of the fasciigera complex because it has a bifurcate gonostylus. However, in this species the shape of the male aedeagus is simple and lacks posterolateral arms as in other species in the fasciigera complex, and, the spermatheca has an elongate oblique neck. Regardless, males of D. pumila differ from males of D. nelidae by their sternite 9 with a rounded posteromedian projection and their nearly straight paramere.

Figures

FIGURE 25. Dasyhelea nelidae n. sp. Holotype male, A – D, Allotype female, E – I. A, E. head. B, G. palpus. C, H. wing. D. genitalia. F. clypeus. I. subgenital plate and spermatheca.

FIGURE 26. Dasyhelea nelidae n. sp. Holotype male. A. genitalia. B. sternite 9. C. gonostylus. D. gonocoxal apodemes and paramere. E. aedeagus. Scale bar: 0.05 mm.