Leptocera schlingeri Richards, 1963

Buck, Matthias & Marshall, Stephen A., 2009, Revision of New World Leptocera Olivier (Diptera, Sphaeroceridae), Zootaxa 2039 (1), pp. 1-139 : 128-130

Leptocera schlingeri Richards, 1963

( Figs. 1 , 30–35 , 305–311 )

Leptocera (Leptocera) schlingeri Richards, 1963: 235 (holotype ♂, CASC, examined).

Leptocera schlingeri .— Roháček et al., 2001: 157 (World catalog).

Description. Body length 1.8–3.1 mm. Habitus as in Fig. 1 . Brown with the following yellow to yellowish brown areas: ocellar triangle, inner surface of antenna (often more or less reddish), palpus, thoracic stripe from postpronotal lobe to notopleural callus (sharply contrasting with medium to dark brown scutum and pleuron), legs except upper half of mid coxa. The brown areas of the body vary from dark brown (vertex, occiput, anterior slope of mesonotum, central stripe of scutum, area mediad of postpronotal lobes, posterior fourth of scutum, scutellum, most of anepisternum and anepimeron, abdominal sclerites except usual pale area on syntergite 1+2, and female terminalia) to pale brown (anterior half of frons, face, gena, sometimes distinct scutal stripes on each side between dorsocentral row and row of enlarged acrostichals [fading out posteriorly], lower pleuron to a variable degree and female terminalia). Wing with yellowish veins, stem vein becoming pale yellow towards base. Tegula and base of costa pale yellow. Orbits without setulae behind level of upper orbital bristle. Arista long-pubescent. Palpus slender. Mesonotum velvety (especially scutellum), pruinose area restricted to a W-shaped anterior area of scutum (bands extending posteriorly ca. 1/3 length of scutum between paramedian rows of acrostichals and laterally along dorsocentral lines) and spots around bases of bristles and hairs of scutum and scutellum (absent from bases of smaller hairs on posterolateral parts of scutum). Four dorsocentral bristles, usually with an enlarged hair in front of first one. Acrostichals sparser than in other species, only 4–6 rows present at level of transverse suture; no row between paramedian rows of enlarged acrostichals. Prescutellar pair of acrostichals slightly to moderately enlarged. Prosternal membrane often with a pair of setulae on each side of midline. Costal sector 1 of wing with unusually short bristles. Fore tarsus slender, similar in both sexes. Mid tibia with lowermost bristle of proximal posterodorsal series short, at most half as long as lowermost bristle of anterodorsal series; bristle above distal dorsal short, clearly shorter than corresponding bristle above distal anterodorsal; posteroapical bristles short, of subequal length. Dorsal surface of hind tibia lacking bristle-like, more or less erect hairs.

Male terminalia ( Figs. 305–308 ): Sternite 5 with wide posteromedial field of black microtrichia; black scales at hind margin numerous, short but robust (median ones shorter than lateral ones). Sternite 8 fused to epandrium. Epandrium with relatively few long bristles ventrally. Anterior section of surstylus with anterior process wide, bearing a bare (devoid of microtrichia), preapical, lateral ridge, which terminates in a small point anteriorly; ventral lobe low, slightly rising posteriorly, bearing a peculiar finger-like posteromedial process with a strong bristle near its base; ventral lobe otherwise with very short hairs except for three long posterior bristles. Posterior section of surstylus relatively slender, with two strong apical/preapical bristles (both with tapered tips) plus two slender bristles of similar length, posterior surface otherwise only with ca. three bristles in basal half. Cercus hemispherical, simple, with numerous bristles. Subepandrial sclerite medially divided ( Figs. 30, 31 ). Aedeagal complex as in Figs. 32–35 . Postgonite with nearly straight posterior margin, shank with patch of microtrichia at base.

Female terminalia ( Figs. 309–311 ): Tergite 7 short, completely pruinose, mid section only with short hairs. Fused tergite 10 + cerci large (much larger than in L. caenosa group), with a pair of long but fine, weak hairs near hind margin, otherwise with several shorter hairs, of which one pair near the centre is slightly enlarged. Sternite 7 wide, with pale, weakly sclerotized hind margin. Spermathecae cylindrical with rounded ends, apical half not wider than basal half, surface with fine transverse ridging.

Type material. Holotype ♂, and 2 ♂♂, 7 ♀♀ paratypes ( CASC): ECUADOR, Prov. Pastaza, 6–8 mi W Mera , 1,500 m, 10.ii.1955, Schlinger & Ross. Of the 9 paratypes we did not examine 1 ♂ and 3 ♀♀.

Other material examined. ECUADOR. Prov. Napo : 1 ♀, Tena , 500 m, 22–27 May 1987, secondary rainforest, malaise, Brown & Coote ( DEBU) ; 1 ♂, 2 ♀♀, 12 km SW Tena , 8–11.vii.1976, dung trap day 2–5 ( DEBU, QCAZ) ; 1 ♂, Jatun Sacha Res. , 6 km E Misahuallí, 1°04'S, 77°37'W, 450 m, 30.iv–8.v.2002, S.A. Marshall ( DEBU) ; 1 ♀, same but 5–7.v.2002, by stream, dung pans ( QCAZ) ; 3 ♂♂, 3 ♀♀, same but 1–2.v.2002, compost, yellow pans, M. Buck ( DEBU, QCAZ) ; 4 ♀♀, same but 1–4.v.2002, pond edge, malaise, Marshall et al. ( DEBU) . Prov. Pastaza : 1 ♀, 70 mi SE Limoncocha , 29.v.1976, malaise, J. Cohen ( USNM) ; 3 ♂♂, 4 ♀♀, Puyo , 2,500 ft, 16.iv.1958, R.W. Hodges ( MSUC) ; 1 ♀, Puyo , 1–7.ii.1976, malaise, Spangler et al. ( USNM) ; 1 ♀, Río Puyo , Levi-Castillo ( USNM) ; 1 ♂, 2 ♀♀, Cononaco , 29.v.1976, malaise, J. Cohen ( USNM) ; 1 ♀, Tewaneo , 19.v.1976, malaise, J. Cohen ( USNM) . Prov. Zamora-Chinchipe : 1 ♂, 1 ♀, Cumbaratza , 12.vi.1976, Langley et al. ( USNM) . PERU. Dpto. Loreto : 6 ♂♂, 6 ♀♀, Campamento San Jacinto , 12.vii.1993, FIT, R. Leschen ( DEBU, MUSM) ; 34 ♂♂, 48 ♀♀, same but 175–215 m, various dates: 3.vi–26.vii.1993 ( DEBU, MUSM) ; 2 ♂♂, 2 ♀♀, 1.5 km N Teniente López , 230–305 m, 18 and 20.vii.1993, FIT, R. Leschen ( DEBU) . Dpto. Madre de Dios : 1 ♀, Los Amigos Biol. Stn. , 2–14.vi.2006, Paiero & Klymko ( MUSM) .

Distribution. An uncommon species of the upper Amazonian basin and adjacent Andean foothills in Ecuador and Peru, from 175 to 1,500 m.

Biology. Some of the specimens examined were collected on compost or dung.

Discussion. This is the most distinctive species of Leptocera in the New World. The contrasting yellow lateral stripes of the thorax immediately identify the species. Besides the remarkable colour pattern the species is characterized by several unique morphological characters such as the absence of hairs between paramedian rows of enlarged acrostichals, short setulae of first costal sector, finger-like posteromedial process of anterior section of surstylus, and cylindrical spermathecae. The phylogenetic affinities of L. schlingeri are uncertain. It might be related to the L. caenosa group based on the apomorphic fusion of sternite 8 and epandrium. However, this character is shared with the L. fulva group.

Figures

FIGURE 1. Leptocera schlingeri, male (Peru).

FIGURES 30–35. Aedeagal complex and subepandrial sclerite of Leptocera schlingeri (Peru): (30) subepandrial sclerite and posterior section of surstylus, lateral; (31) subepandrial sclerite, posterior section of surstylus and right cercus, posterior; (32) base of phallapodeme, postgonites and phallus, dorsal; (33) aedeagal complex, lateral; (34) same, posterior; (35) same, anterior. bcp—basal connection between postgonites, bp—basiphallus, ce—cercus, dp—distiphallus, ea—ejaculatory apodeme, pa—phallapodeme, pg—postgonites, pss—posterior section of surstylus.

FIGURES 305–311. Leptocera schlingeri (Peru). Male terminalia (phallus and postgonites omitted): (305) lateral; (306) posterior; (307) ventral; (308) sternite 5. Female terminalia: (309) dorsal; (310) spermathecae; (311) ventral. ce—cercus, proc—posteromedial process of anterior section of surstylus.