Paraleucopis Malloch, 1913

Wheeler, Terry A. & Sinclair, Bradley J., 2019, Systematics of Paraleucopis Malloch with proposal of Paraleucopidae, a new family of acalyptrate Diptera, Zootaxa 4668 (3), pp. 301-328 : 304-307

Paraleucopis Malloch, 1913

Paraleucopis Malloch, 1913: 148 . Type species: Paraleucopis corvina Malloch (by original designation). Steyskal, 1971: 1 (revision); Steyskal, 1981: 403 (revision, key to species); Wheeler, 2010: 1011 (summary).

Diagnosis. This genus is distinguished from other Paraleucopidae by a broad gena; postpronotal bristle present; anal area of wing well-developed, wing broadest near anal angle; wing veins white or yellow; halter white.

Description. Frons shiny; ocellar bristles distinct, proclinate, divergent; postocellar setae very short and weak, divergent; 2 vertical bristles, divergent; 1–2 erect orbital bristles usually present; fronto-orbital setulae proclinate; interfrontal setulae proclinate. Lunule broad, large, microtomentose. Face vertical, microtomentose, concave in lateral view; ventral margin deeply incised medially. Antennal bases usually separated by more than length of pedicel, postpedicel small, arista almost bare. Eye round. Gena very broad, swollen, curved inward toward oral cavity in ventral half, vibrissa not differentiated from genal setae, subgena visible in lateral view, postgena broad.

Scutal chaetotaxy: 1 postpronotal, 2 notopleural, 1 postsutural dorsocentral, 2 long postalar bristles. Scutum usually shiny. Scutellum convex, shiny. Subscutellum convex, microtomentose. Thoracic pleurites shiny, bare except for katepisternal bristle, setulae on katepisternum and posterior half of anepisternum; katepisternum with stronger setae near ventral margin. Wing broad, anal area and alula well-developed ( Fig. 9 ); veins white or yellow; 1 anteroventral seta proximal to costagial break and 1 seta on tegula; Sc incomplete, ending just before C, not fused with R 1 distally; C short spinose beyond R 1; R 4+5 and M 1 converging distally; CuA+CuP (anal vein) long and straight, ending before wing margin; outstanding marginal setulae between apices of R 4+5 and M 1 apparently absent. Halter pale.

Abdomen short, broad, tergites 1 and 2 and anterior part of tergite 3 densely microtomentose, rest of abdomen shiny; tergites 1 and 2 separated dorsally by distinct transverse suture. Tergites 1–5 with short, sparse setae and long dark lateral marginal setae; sternites 1–5 quadrate, narrow, with sparse setae. Male sternite 5 entire or with narrow posterior region divided by membranous region from rest of sternite. Spiracles 1–5 in pleural membrane near lateral margin of tergites.

Male postabdomen: tergite 6 relatively broad, dorsal, slightly asymmetrical; sternite 6 large, asymmetrical, ventral and left lateral. Sixth spiracles in pleural membrane near lateral margins of tergite 6. Tergite 7 in form of long, narrow strip on right side of postabdomen; sternite 7 large, asymmetrical, on left side posterior to sternite 6, narrower dorsally. Sternite 8 asymmetrical, as broad as sternites 6 and 7 combined ( Fig. 46 ). Epandrium rounded, evenly sclerotized, setose. Hypandrium broader along anterior margin. Surstylus articulated with epandrium, long, narrow. Subepandrial sclerite dark, narrow. Phallapodeme short, straight; phallic guide forming narrow ventral plate, not attached to hypandrium. Pregonite long, apparently fused with hypandrium laterally. Postgonite short, posteroventrally directed, articulated with pregonite. Basiphallus with sclerotization interrupted posteriorly; distiphallus long, bare, transversely striated, with long, narrow, lateral sclerites. Ejaculatory apodeme reduced; ejaculatory duct unmodified.

Female postabdomen ( Fig. 10 ): tergite 6 long, roughly quadrate, constricted medially; sternite 6 largely desclerotized, reduced to 2 small anterior sclerites and posterior setae (see Steyskal 1971, fig. 6). Spermathecae 2, sclerotized, clavate, denticulate; third spermatheca rudimentary. Ventral receptacle small, rounded ( Fig. 41 ). Cercus elongate and slender.

Remarks. The monophyly of Paraleucopis is supported by the following synapomorphies: gena broad, anal angle of wing broad, wing veins white, costa spinose, ejaculatory apodeme greatly reduced. The illustration of the wing of Paraleucopis corvina is incorrect in McAlpine (1987, fig. 10) and in other publications where this figure is reproduced. The Sc ends abruptly prior to a preapical expansion of R 1 and not complete as drawn (see Fig. 9 ).

The genus occurs primarily in the southwestern United States, northwestern Mexico (including Baja California) and northern regions of Argentina and Chile.

Figures

FIGURES 8–10. Female Paraleucopis. 8, Paraleucopis saguaro sp. nov., habitus; 9, P. saguaro sp. nov., wing; 10, P. corvina, postabdomen, dorsal view. Abbreviation: tg—tergite. Scale bars = 0.5 mm, except Fig. 10 where scale bar = 0.25 mm.

FIGURES 45–48. Male terminalia and male postabdomen of Paraleucopis spp. 45, P. nigra sp. nov., male terminalia, lateral view; 46, P. paraboydensis sp. nov., postabdomen, ventral view; 47, P. paraboydensis sp. nov., male terminalia, lateral view; 48, P. paraboydensis sp. nov., male terminalia, ventral view. Abbreviations: st—sternite; sur—surstylus; tg—tergite. Scale bars = 0.1 mm.

FIGURES 37–42. Male terminalia, spermathecae and female tergite 6 of Paraleucopis spp. 37, P. corvina, male terminalia, lateral view; 38, P. corvina, female tergite 6, dorsal view; 39, P. corvina, spermathecae; 40, P. mexicana, male terminalia, lateral view; 41, P. mexicana, spermathecae and ventral receptacle; 42, P. mexicana, female tergite 6, dorsal view. Abbreviations: v rep—ventral receptacle. Scale bars = 0.1 mm.