Dasyhelea latiala, 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 : 311-314

Dasyhelea latiala n. sp.

( Figs. 11–21 , 58–60 )

Diagnosis. The only Neotropical species of the mutabilis group with the following combination of characters. Males 3 rd palpal segment slender, palpal ratio 4.00; gonocoxal apodemes slightly asymmetrical; paramere, slender with bifid apex; aedeagus very complex, composed of two sections, a heavily sclerotized basal portion and a hyaline distal portion; and tergite 9 with rounded apical region that extends considerably beyond gonocoxites and elongate, stout, broadly divergent widely spaced apicolateral processes. Females with moderately long antennal flagellum, flagellomeres 2–8 moniliform to vasiform, 9–13 elongate, much longer than 2–8 and antennal ratio 0.78–0.97; palpus moderately long, segment 5 extending beyond tip of proboscis; wing very broad, length/width ratio 2.03–2.16; subgenital plate with a sub-circular basal portion with an ovoid lumen and a very broad trapezoidal apical portion; spermatheca moderately large (42.5 x 37.5 µm), ovoid, heavily sclerotized with a short, slightly recurved neck.

Male. Head ( Fig. 11 ). Dark brown. Eyes contiguous for a distance equal to the width of 2 ommatidia. Antennal flagellum with flagellomeres 2–9 rhomboid, 10–13 elongate, 13 broader than 10–12; 2–10 with single whorl of long sensillae chaetica comprising the dense plume; antennal ratio 0.97; flagellum length 0.51 mm. Frontal sclerite rhomboidal, with slender elongate ventral extension. Clypeus ( Fig. 12 ) with 4 pairs of setae. Palpus ( Fig. 13 ) brown, elongate, apex extending considerably beyond tip of proboscis; segment 3 slender, as long as 4+5 combined, apex extending near apex of proboscis, with scattered capitate sensillae on inner surface; palpal ratio 4.00. Thorax. Scutum dark brown; scutellum pale brown with 6 large, 2 smaller setae. Wing ( Fig. 14 ) moderately slender; membrane hyaline with moderately dense macrotrichiae; veins brown; 2 nd radial cell very short, open apically; apices of costa, radius perpendicular with wing margin; fork of CuA 1 at level of base of 2 nd radial cell; anal lobe moderately developed; wing length 0.80 mm, width 0.27 mm; costal ratio 0.46. Abdomen. Dark brown. Genitalia ( Figs. 15 , 58–60 ). Tergite 9 base broad, tapering progressively distally to rounded apex that extends considerably beyond gonocoxites; apicolateral processes elongate, stout, broadly divergent with subapical seta; cercus conspicuous, located at base of apicolateral process with 3–4 setae. Sternite 9 ( Figs. 15 , 58 ) 0.45 length of width; base broadly curved; posteromedian portion broad, tapering slightly distally with notched apex. Gonocoxite stout, 1.7 x longer than broad, distal margin straight, apicomesal surface with group of dense, moderately long setae; gonostylus nearly as long as gonocoxite, proximal 1/2 broad, tapering abruptly at mid-length, slightly curved with pointed tip. Paramere and gonocoxal apodemes ( Figs. 15 , 59 ) nearly symmetrical; gonocoxal apodemes slender on proximal 1/2, distal portions broader with small basal spur, apices truncate; paramere slender, nearly straight, apex bifurcate.Aedeagus ( Figs. 15 , 60 ) 0.60 length of greatest width, very complex, composed of two sections; basal arch stout, slightly curved, extending nearly 0.50 of total length, distal margin notched; basal arm stout, anterolaterally directed with mid-posterior outer tooth; posterior projection short, stout, with slightly expanded rounded tip; distal portion covered by a hyaline envelope that reaches tips of posteromedian projection and borne on pair of slender, heavily sclerotized processes directed anterolaterally, contiguous to inner margin of basal arms.

Female. Head ( Fig. 16 ). Dark brown. Eyes contiguous for a distance equal to the width of 2–3 ommatidia. Antennal flagellum with flagellomeres 2–8 moniliform to vasiform, 9–13 longer than 2–8, 13 longest; antennal ratio 0.78–0.97 (0.87, n=2); flagellum length 0.37–0.40 (n=2) mm. Frontal sclerite rhomboidal, with slender elongate ventral extension. Clypeus ( Fig. 17 ) with 7 pairs of setae; anterior margin concave. Palpus ( Fig. 18 ) light brown; segment 3 nearly as long as 4+5 combined, with scattered capitate sensillae on mesal surface; palpal ratio 3.66 (n=2). Thorax ( Fig. 19 ). Scutum dark brown, paler on humeral angles and prescutellar depressions; scutellum yellowish, with 6 large, 2 smaller setae. Legs light brown, tarsomeres 5 more darkly infuscated; hind tibial comb with 6 spines; prothoracic tarsal ratio 2.14–2.25 (2.19, n=2), mesothoracic tarsal ratio 2.00, metathoracic tarsal ratio 2.18–2.22 (2.20, n=2). Wing ( Fig. 20 ) very broad, length/width ratio 2.03–2.16; membrane hyaline with dense macrotrichiae; veins brown; 2 nd radial cell very short, open distally; apices of costa, radius at slight oblique angle with wing margin; fork of CuA 1 just anterior to base of 2 nd radial cell; anal lobe well developed; wing length 0.65–0.80 (0.72, n=2) mm, width 0.32–0.37 (0.35, n=2) mm; costal ratio 0.50 (n=2). Halter yellowish. Abdomen ( Fig. 21 ). Dark brown. Subgenital plate ( Fig. 21 ) with a sub-circular basal portion with an ovoid lumen and broad trapezoidal apical portion; posteromedian margin rounded with a small bifurcate posteromedian projection; posterolateral arms slender, recurved 30˚ at mid-length. Spermatheca ( Fig. 21 ) small (42.5 x 37.5 µm), ovoid, heavily sclerotized; neck short, slightly recurved, length 12.5 µm.

Distribution. Curaçao.

Type Material. Holotype male, labeled “ Curaçao, Piscadera Baai, 5-XII-2015, M. C. Thomas, Blacklight trap in mangroves”; allotype female with same data except 0.5 km N of Cambi , 12°07ʹ36.88ʹʹ N, 69°58ʹ1.14ʹʹ W, 6-XI- 2014 (deposited in FSCA). One female paratype with same data as holotype (deposited in MLPA).

Derivation of specific epithet. The specific epithet was derived from two Latin terms, lati (broad, wide) and ala (wing), a reference to the very broad wing ( Fig. 20 ) of females of this new species.

Discussion. The paramere of the holotype male of D. latiala n. sp. is similar to males of D. yamana Díaz & Spinelli (in Díaz et al. 2014: Fig. 17E ) from Tierra del Fuego province, Argentina which have a slightly shorter, narrower paramere with a more deeply bifid apex. In addition, the gonocoxal apodemes of D. yamana are also symmetrical with a short basolateral spur that is similar to the more elongate basolateral spurs on the larger, nearly symmetrical gonocoxal apodemes of D. latiala . However, males of D. yamana differ from the holotype of D. latiala in having a much longer wing (wing length 1.14–1.23 mm vs. 0.80 mm in D. latiala ) that is not as narrow with a more poorly developed anal lobe; a more typical aedeagus with a large, stout posteromedian projection, a broad nearly straight basal arch and slender posterolateral arms with recurved tips; sternite 9 has a longer, more narrow distal extension; stouter gonostyli; and tergite 9 has shorter, less widely divergent apicolateral processes. Females of D. yamana differ from females of D. latiala n. sp. in having a shorter antennal flagellum with only flagellomeres 9–13 slightly longer than broad; a more elongate 3 rd palpal segment with a larger palpal ratio (4.00–4.80 vs. 3.66 in D. latiala ); a longer wing (wing length 0.93–1.08 mm vs. 0.65–0.80 mm in D. latiala ) with a shorter costa (costal ratio 0.41–0.45 vs. 0.50 in D. latiala ) with a more poorly developed anal lobe; a broader frontal sclerite in which the dorsal portion is fused with the narrower ventral portion; a more typical semi-circular subgenital plate but without a broad trapezoidal anterior portion and posteromedian projection; and a spherical spermatheca with a short straight neck.

Males of D. williamsi Wirth & Waugh (1976) have a very short broader paramere but the distal 2/3 is deeply bifid and their apices are broad and widely separated; the shape of the aedeagus is much different with long, stout lateral arms that are widely spaced basally, curved distally with broad nearly convergent tips; the distal 1/2 of the gonostyli are much broader; tergite 9 is much shorter with a straight margin and very short apicolateral processes; and sternite 9 is more elongate and extends just below the apex of the aedeagus. In addition, the thorax and much of the abdomen of both sexes of D. williamsi is mostly yellowish.

Finally, the very unusual, greatly complex aedeagus of the holotype male of D. latiala does not resemble the aedeagi of other males in the mutabilis group including those in the fasciigera complex. Accordingly, it is possible that we have not correctly associated both sexes of this species. However, we are fairly confident of their association as all three specimens in the type series were collected in the same region and their overall colorations are similar.

Figures

FIGURES 11–21. Dasyhelea latiala n. sp. Holotype male, 11–15, allotype female, 16–21. 11, 16 head. 12, 17 clypeus. 13, 18 palpus. 14, 20 wing. 15 genitalia. 19 thorax. 21 apex of abdomen and spermatheca. Scale bars = 0.05 mm.

FIGURES 52–69. Male Dasyhelea genitalia structures: sternites 9 (left column), gonocoxal apodemes and parameres (middle column), and aedeagi (right column). 52–54 D. aliciae n. sp., 55–57 D. recurva n. sp., 58–60 D. latiala n. sp., 61–63 D. cyrtostyla n. sp., 64–66 D. curacaoensis n. sp., 67–69 D. rhopaloparamera n. sp. Scale bars = 0.05 mm.