Leptocera aequilimbata Duda, 1925

Buck, Matthias & Marshall, Stephen A., 2009, Revision of New World Leptocera Olivier (Diptera, Sphaeroceridae), Zootaxa 2039 (1), pp. 1-139 : 23

Leptocera aequilimbata Duda, 1925

( Figs. 4 , 38–44 , 138 )

Leptocera (Paracollinella) aequilimbata Duda, 1925: 58 (lectotype ♂, present designation by M. Buck, SMTD). Leptocera aequilimbata .— Roháček et al., 2001: 150 (World catalog).

Description. Relatively small, body length 1.8–2.4 mm. Completely dark brown and lacking paler areas found in related species. Arista short-pubescent ( Fig. 4 ). Palpus slender. Mid tibia with bristle above distal dorsal about 0.5–0.7x as long as distal anterodorsal bristle. Mid tibia with lowermost bristle of proximal posterodorsal series as long as or slightly longer than lowermost bristle of anterodorsal series; posteroapical bristles short, ventral one up to twice as long as dorsal one.

Male terminalia ( Figs. 38–41 ): Sternite 5 with relatively small posteromedial field of enlarged microtrichia; hind margin with 5–8 weak and short scales, lateral ones often shorter than medial ones; length of scales varies geographically: scales very short in specimens from Cusco region, longer in specimens from Lake Titicaca area. Epandrium with relatively few long bristles ventrally. Anterior section of surstylus with apex of anterior process strongly sclerotized, pointed and curved laterally; ventral lobe little produced, with short to moderately long bristles; long posterior bristle inserted relatively close to dorsal margin (compare L. longilimbata sp.n.). Posterior section of surstylus with small, tooth-like anterior process at base, medial margin desclerotized, apical area with the usual two strong bristles (lateral one shorter and with blunt tip), posterior surface with few long pale hairs. Cercus with both finger-like, microtrichose and transparent, bare, lamellate medial process (finger-like process weakly sclerotized, sometimes inconspicuous and easily overlooked). Postgonite with deep posterobasal notch ( Fig. 138 ).

Female terminalia ( Figs. 42–44 ): Tergite 7 long and strongly convex, anteriorly with a pair of strong, cruciate bristles, surface microtrichose and dull throughout except for narrowly shining hind margin. Sternite 7 with thickened and narrowly shining hind margin (often difficult to appreciate in slightly teneral specimens). Sternite 8 very wide. Fused tergite 10 + cerci short, with short hairs. Spermathecae elongate, with weakly striate surface.

Type material. Lectotype ♂, designated here by M. Buck ( SMTD): PERU, Dpto. Cusco, Cuzco, 3,700–4,000 m, 17.vi.1905 . Paralectotypes (all SMTD): PERU. Dpto. Cusco: 1 ♂, same as lectotype but 3,500 –4,200 m, 24.v.1905 ; 1 ♂, 1 ♀, same but 3,700 –4,200 m; 1 ♂, 1 ♀, same but 4,000 –4,200 m, 12.vi.1905; 1 ♂, Cuzco, O. Garlepp ; 2 ♂♂, “Laristhal” [= Lares Valley , ~ 50 km N Cuzco], 3,000 –4,000 m, 9.viii.1903 . Dpto. Puno: Puno, “Titicaca-See” [= Lago Titicaca], 1 ♀, 17.xi.1902 , 1 ♂, 21.xi.1902 . BOLIVIA. Dpto. La Paz : 1 ♀, Guaqui, “Titicaca-See” [= Lago Titicaca], 30.v.1903 . Note : Duda (1925) mentions a total of 10 ♂♂ and 6 ♀♀ syntypes at the SMTD but we were only able to locate 8 ♂♂ and 4 ♀♀ .

Other material examined. PERU. Dpto. Puno: 2 ♂♂, 2 ♀♀, La Huerta, 3,800 m, 24–28.xi.1955, L.E. Peña ( CNCI) . Dpto. Junín: 1 ♀ (tentatively identified as L. aequilimbata ), Ondores, 4,100 m, 28–31.xii.1980, Puna and wet pastures, Gärdenfors et al. ( MZLU) . BOLIVIA. Dpto. La Paz : 8 ♂♂, 1 ♀, Lago Titicaca, Mapac, Sahuiña, 3,812 m, 23.iv.1997, L. Masner ( DEBU, CBFC) ; 2 ♂♂, 3 km E Desaguadero, shore Lago Titicaca , 16°33'26"S, 69°01'21"W, 19.iv.2001, shoreline drift, sweep, S.A. Marshall ( DEBU) . ARGENTINA. Prov. Jujuy: 1 ♂, Lecho, 32 km E La Quiaca, 3,300 m, 24.x.1968, L.E. Peña ( CNCI) .

Distribution. An uncommon, high elevation species of the Andes (3,300 to at least 4,100 m), ranging from south Peru to northern Argentina.

Discussion. This species is readily characterized by the small marginal scales of male sternite 5 and the entirely pruinose disc of female tergite 7 in conjunction with weakly striate spermathecae. Further diagnostic characters include the short-pubescent arista and the presence of both finger-like and transparent, lamellate processes to the male cercus (both characters shared with the closely related L. longilimbata sp.n.).

Figures

FIGURES 2–6. Leptocera heads and antennae. Heads of (2) L. argentinica sp.n. (Argentina); (3) L. fulva (Costa Rica). Arista and first flagellomeres of (4) L. aequilimbata (Peru); (5) L. neocurvinervis (Chile); (6) L. caenosa (U.S.A.). ad s—additional setulae on orbit, l or—lower orbital bristle, u or—upper orbital bristle.

FIGURES 38–44. Leptocera aequilimbata (38–40: Argentina, 41–44: Bolivia). Male terminalia (phallus and postgonites omitted): (38) lateral; (39) posterior; (40) ventral, right cercus omitted; (41) sternite 5. Female terminalia: (42) dorsal; (43) spermathecae; (44) ventral. aps—anterior process of anterior section of surstylus, cb—cruciate bristles, ce—cercus, cp—finger-like process of cercus, ep—epandrium, fm—field of dense microtrichia, ha—hypandrial apodeme, hy—hypandrium, lp—lamellate process of cercus, pa—phallapodeme, proc—process at base of posterior section of surstylus, pss—posterior section of surstylus, S—sternite, sc—enlarged scales, se—subepandrial sclerite, T—tergite (female tergite 8 divided into two halves), vap—ventral appendage of tergite 8, vls—ventral lobe of anterior section of surstylus.

FIGURES 138–146. Postgonites and aedeagal complex of Leptocera caenosa group. Postgonites of (138) L. aequilimbata (Argentina), (139) L. argentinica sp.n. (Argentina), (140) L. neocurvinervis (Chile), (141) L. erratica sp.n. (South Africa), (142) L. sphaerotheca sp.n. (U.S.A.), (143) L. ellipsipennis (Juan Fernández Is.), (144) L. parallelipennis sp.n. (Juan Fernández Is.), (145) L. cultellipennis (Juan Fernández Is.). Aedeagal complex of (146) L. duplicata (Juan Fernández Is.). bp—basiphallus, dp—distiphallus, ea—ejaculatory apodeme, pa—phallapodeme, pg—postgonites.