Forcipomyia (Trichohelea) tehuelche, Marino & Spinelli, 2004

Marino, Pablo I. & Spinelli, Gustavo R., 2004, Descriptions of the Patagonian species of the subgenus Trichohelea of Forcipomyia, with a key to the Neotropical species (Diptera: Ceratopogonidae), Journal of Natural History 38 (17), pp. 2251-2262 : 2260-2261

Forcipomyia (Trichohelea) tehuelche sp. n.

(figures 18–23)

Diagnosis

A medium-sized, brown species; flagellomeres 1–8 distinctly broader than long; third segment of maxillary palpi broadly swollen, sensory pit deep opening by a small pore; CR 0.55; tarsal claws equal, small, bifid at extreme apex; female genital sclerotization open, subquadrangular; two pyriform spermathecae; aedeagus stout with distal medial process, basal arch extending to one-tenth of total length; parameres inverted U-shaped, lateral arms subparallel.

Female

Wing. Length 1.26 mm (1.22–1.30, N ~2); breadth 0.56 mm (0.54–0.58, N ~2).

Head. Dark brown. Vertex pilose. Eyes bare, contiguous by a distance equal to diameter of three ommatidia. Flagellum of antenna with flagellomeres 1–8 distinctly broader than long; 9–12 elongated, cylindrical, approximately 2.5 times longer than greatest breadth; distal flagellomere slightly longer than 9–12; AR 1.68 (1.62–1.74, N ~2). Palpus short; third segment broadly swollen at midportion, nearly as long as the combined length of fourth and fifth segments, with deep sensory pit opening by a small rounded pore; fifth segment slightly narrower than 4; PR 1.70 (1.59–1.81, N ~2). Mandible abruptly tapering to pointed apex, armed with 10 very small teeth. Maxilla slender, nearly straight, with six pairs of minute teeth.

Thorax. Scutum brown, humeral areas slightly paler; scutellum pale brown, with approximately 20 strong setae and 15 slender ones. Legs pale brown, densely covered by hairs; prothoracic TR 1.93 (1.92–1.93, N ~2), mesothoracic TR 1.87 (1.86–1.87, N ~2), metathoracic TR 1.88 (1.87–1.88, N ~2). Claws small, very curved, moderately stout, bifid at extreme apex; empodium well developed. Wing densely covered with macrotrichia, more abundant on anterior margin; a small pale area situated immediately distad to the second radial cell; first radial cell almost obliterated, second radial cell well formed; CR 0.55 (0.54–0.55, N ~2). Halter whitish.

Abdomen. Pale brown, pilose. Genital sclerotization open, subquadrangular. Two pyriform, well-sclerotized spermathecae, subequal, measuring 0.062× 0.050 mm and 0.052× 0.044 mm, necks of 0.006 mm.

Male

Wing. Length 1.38 mm; breadth 0.46 mm.

Similar to female with the usual sexual differences: eyes bare except inner margin with sparse pilosity; flagellomeres 1–9 similar in length, 10–13 (figure 18) in proportion of 56-43-35-47; AR 1.22; palpus (figure 19) with third segment slightly shorter than the combined length of fourth and fifth segments, segments in

proportion of 11-19-30-18-18; PR 2.5; tarsal claws equal, small, 0.5 times as long as tarsomere 5, bifid at extreme apex, empodium absent; prothoracic TR 1.44, mesothoracic TR 1.53, metathoracic TR 1.83; wing (figure 20) with CR 0.46.

Genitalia (figure 21). Sternite 9 stout, 0.66 times longer than greatest breadth, with narrow, shallow caudomedian excavation; tergite 9 tapering, with conspicuous, pilose apicolateral processes; sternite 10 spiculate. Gonocoxite 2.3 times longer than greatest (basal) breadth; gonostylus 0.85 as long as gonocoxite, slen-

der, nearly straight, tip pointed. Aedeagus stout, slightly sclerotized; basal arms short, recurved; basal arch very low, extending to one-tenth of total length; lateral arms convex; distal portion very lightly sclerotized, tapering to pointed tip, with a pair of subapical, lateral pointed processes (figure 22). Parameres (figure 23) highly sclerotized, inverted U-shaped, lateral arms subparallel.

Distribution

In subantarctic forest of southern Patagonia (Santa Cruz province in Argentina) ( figure 24 ).

Types Holotype „; allotype ”, Argentina, Santa Cruz Prov., Lake del Desierto , 9–11

December 1996, G. Spinelli, malaise trap; paratype ”, same data except 9 December 1996, sweep net.

Discussion

Females of F. (T.) tehuelche are barely distinguishable from those of F. (T.) limnetis . Characters to distinguish their males may be found in the discussion under the latter species.

Figures

FIG. 24. Known localities for the Patagonian species of the subgenus Trichohelea.