Leptocera cultellipennis ( Enderlein, 1938 )

Buck, Matthias & Marshall, Stephen A., 2009, Revision of New World Leptocera Olivier (Diptera, Sphaeroceridae), Zootaxa 2039 (1), pp. 1-139 : 62-64

Leptocera cultellipennis ( Enderlein, 1938)

( Figs. 13 , 110–116 , 145 )

Skottsbergia cultellipennis Enderlein, 1938: 650 (holotype ♀, NHRS, not examined).

Leptocera cultellipennis .— Roháček et al., 2001: 152 (World catalog).

Description. Body length 1.8–2.7 mm. A brown species, frons and inner surface of pedicel more or less reddish. The following areas of thorax are paler brown, with a somewhat reddish tinge: postpronotal lobes, notopleuron and adjacent parts of transverse suture, postalar callus, entire scutellum, postnotum (mediotergite darker than laterotergite). Scutum with four dorsocentral bristles (anterior one at most half as long as the one behind it). Third dorsocentral bristle from behind noticeably shifted forward: its socket in front of line connecting sockets of presutural supra-alar and presutural intra-alar bristles (the latter greatly reduced and barely longer than other hairs of scutum). Wing rudiment narrow and apically pointed, lacking all veins except costa beyond apex of R 1 ( Fig. 13 ). Mid tibia with bristles of proximal posterodorsal series slightly less shifted ventrally than in other species, its lowermost bristles inserted almost exactly at middle (not below middle) of mid tibia. Bristle above distal dorsal bristle shorter than corresponding bristle above distal anterodorsal. Dorsal posteroapical bristle short, ventral posteroapical not differentiated (as in Fig. 18 ).

Male terminalia ( Figs. 110–113 ): Sternite 5 with small microtrichose posteromedial area, lacking enlarged scales at hind margin. Surstylus with anterior process of anterior section rounded apically and with small anterior point; ventral lobe relatively short and high, ventral margin straight to concave, with relatively long bristles; the long posterior bristle on a small prominence. Posterior section of surstylus with two strong bristles close to apex, both with fine tips (outer one shorter and less tapered); inner margin of surstylus only very narrowly desclerotized (requires careful observation), posterior surface of surstylus with few bristles. Cercus with a completely transparent, lamellate medial process (requires careful observation); inner edge of sclerotized part with fairly large microtrichia, grouped into a small tuft near middle. Postgonite with posterobasal notch of moderate width ( Fig. 145 ).

Female terminalia ( Figs. 114–116 ): Tergite 7 often paler posteriorly, relatively short, slightly convex, pruinose except for slightly shining, narrow hind margin; enlarged paramedian bristles moderately strong and convergent, rarely cruciate. Sternite 7 becoming paler posteriorly except for dark brown, shining hind margin. Sternite 8 not emarginate on each side of posteromedial lobe. Tergite 10 + cerci relatively long, with few short hairs. Spermathecae elongate, dilated apical portion finely striate.

Type material. Holotype ♀ ( NHRS, not examined): CHILE, Masatierra [= Robinson Crusoe I.], 1917. Note: examination of the type was not necessary because the species is easily recognised and restricted to one small island.

Other material examined. CHILE. Reg. Aconcagua: 97 ♂♂, 100 ♀♀, Juan Fernández Is., Robinson Crusoe I., from the following localities: lower, upper, and highest part El Yunque trail, Plazoleta del Yunque , above Plazoleta, Damajuana, N side Mirador de Selkirk, quebrada on S side Mirador de Selkirk, Rabanal, Puerto Inglés, Puerto Francés, various dates: 23–30.i.1992 and 31.xii.1992 – 12.i.1993, various habitats: open forest, fern forest, mossy seep, creek, steep eroded slope, various methods: pan traps, aspirated, Berlese, S.A. Marshall ( DEBU, IESC) .

Distribution. Endemic to Robinson Crusoe I. (Juan Fernández Is., Chile).

Discussion. This species is easily recognised based on the narrow, apically pointed wing rudiment. It differs furthermore from other Juan Fernández Leptocera by its paler and somewhat reddish scutellum and the unusual forward position of the third dorsocentral bristle from behind. The male genitalia are similar to L. duplicata but the ventral lobe of the anterior section of the surstylus is relatively short and its ventral margin straight to concave (not slightly convex).

Figures

FIGURES 10–15. Leptocera wings: (10) L. fulva (Belize); (11–12) L. ellipsipennis, showing variation (Juan Fernández Is.); (13) L. cultellipennis (Juan Fernández Is.); (14) L. parallelipennis sp.n., normal wing venation (Juan Fernández Is.); (15) ditto, aberrant venation. Scale bar 0.1 mm. Cs—costal sector.

FIGURES 110–116. Leptocera cultellipennis (Juan Fernández Is.). Male terminalia (phallus and postgonites omitted): (110) lateral; (111) posterior; (112) ventral; (113) sternite 5. Female terminalia: (114) dorsal; (115) spermathecae; (116) ventral. lp—lamellate process of cercus.

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.

FIGURES 16–29. Leptocera mid tibiae and basitarsi. Mid tibia, dorsal: (16) L. neocurvinervis (Chile); (17) L. duplicata (Juan Fernández Is.). Apical half of mid tibia and basitarsus, posterior: (18) L. parallelipennis sp.n. (Juan Fernández Is.); (19) L. ellipsipennis (Juan Fernández Is.); (20) L. erythrocera (Honduras); (21) L. sphaerotheca sp.n. (Mexico); (22) L. plax sp.n. (Ecuador); (23) L. tapanti sp.n. (Costa Rica); (24) L. cymatonota sp.n. (Mexico); (25) L. parafinalis (Canada); (26) L. neofinalis sp.n. (Canada); (27) L. kanata sp.n. (Canada); (28) L. fontinalis (France); (29) L. nigra (South Africa). d ad—distal anterodorsal bristle, d d—distal dorsal bristle, d pa—dorsal posteroapical bristle, l ad—lowermost bristle of proximal anterodorsal series, l pd—lowermost bristle of proximal posterodorsal series, mv—midventral bristle, pa v—preapical ventral bristle, vb—ventrobasal bristle of basitarsus, v pa—ventral posteroapical bristle.