Systellapha Enderlein 1922
Creators: name: Marshall, Stephen A.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Micropezidae
Systellapha

description: Systellapha Enderlein
Systellapha Enderlein, 1922: 189. Type species: Systellapha ornatithorax Enderlein (orig. des.).
Generic description: Length 7–10 mm. Colour: Mostly dark brown, frontal vitta velvety black and broadly convex anteriorly, orange to brown posteriorly; pedicel orange with short black setulae, first flagellomere orange with pale setulae. Palpus black. Epicephalon glossy brown, reddish to dark brown anteriorly; paracephalon microtrichose. Notum with conspicuous silvery microtrichose vittae laterally and sometimes with less conspicuous narrow vittae in central darker area, thoracic pleuron with vertical to diagonal silvery microtrichose bands. Fore and hind tarsi entirely white. Mid femur and hind femur yellowish brown with variously developed dark brown rings in basal and distal halves. Female with shining brown oviscape.
Head: Arista sparsely short-plumose on basal 3/4, bare distally; pedicel with apical ventral bristle almost as long as scape; first flagellomere 1.5X as long as wide. Palpus extremely broad, strongly convex ventrally, dorsal apex pointed. Clypeus prominent, shining, microtrichose only at posterior corners. Two large fronto-orbital bristles, one anterior and one posterior. Black anterior part of pre-ocellar portion of frontal vitta convex, broadly rounded or tapered to anterior margin; remainder of frontal vitta and paracephalon flat. Orbital plate sparsely setulose. Inner and outer vertical and postocellar bristles well-developed, inner verticals and postocellars in an almost straight row.
Thorax: Scutellum and a small prescutellar middle part of scutum silvery microtrichose. Cervical sclerite simple, postpronotum microtrichose with a few scattered minute setulae. One short suprahumeral bristle. One or two well-developed postsutural dorsocentral bristles. Wing with a large inclinate costagial bristle (as long as supraalar) and large but diffuse discal and apical bands; second costal sector slightly longer than third (1.1–1.2X); anal cell short, distal angle forming an equilateral triangle.
Female abdomen with oviscape as long as remainder of abdomen. Spermatheca with long major duct and much shorter minor duct arising separately from tapered apex of bursa copulatrix, both ducts leading to paired spermathecae on separate stems, stems of larger spermathecae pigmented and with small processes. Ventral receptacle small to indistinct.
Male abdomen with epandrium elongate, anteroventral arms long and articulating with long posterior hypandrial arms and base of hypandrial bridge. Sternite 5 with an elongate genital fork, with inner basal lobes and spines on inner surfaces of arms; arms long, slender, incurved and distally downturned. Basal distiphallus dorsoventrally flattened, forming a deep V-shape with the arms of the V articulating with the small basiphallus and overlapped by very small and inconspicuous postgonites. Distal distiphallus and anterior tongue of hypandrium exceptionally long, hypandrium longer than epandrium, distal distiphallus threadlike.
Similar genera: Although Systellapha has been widely treated as a synonym of Grallipeza, it is unlikely that Systellapha and Grallipeza are closely related. Grallipeza males, like males of Calosphen Hennig, are characterized by a small epandrium, a short phallus ending in a large phallic bulb (the distal distiphallus is thus absent), and a broad and scoop-like hypandrium. This contrasts sharply with the elongate epandrium, narrow hypandrium and thread-like distal distiphallus of Systellapha. Internal female characters of Systellapha, especially the four spermathecae including a large pair and a much smaller pair on a short duct, also differ widely from Grallipeza. A few Grallipeza species also have two pairs of spermathecae, but these species have two spermathecal ducts of similar length and have a greatly enlarged ventral receptacle, in marked contrast to the unequal spermathecal ducts and minute ventral receptacle of Systellapha. All three species of Systellapha were sequenced for the barcode region of CO1, supporting their recognition as distinct but closely related species widely separated from the type species of Grallipeza.
Distribution: Systellapha was previously known only from southern Brazil and Paraguay; the genus is here newly recorded from Argentina.
Key to the species of Systellapha
1. Dorsocentral bristles in single pair (Fig. 2A). Notum with narrow central silvery vitta bisecting a broad brown middle part (Fig. 2A). Genital fork (sternite 5) of male with 2-3 long, narrow inner basal lobes each ending in 1-2 spurs (Fig. 1B)................................................................................... Systellapha digifurca new species.
– Dorsocentral bristles in two pairs (Fig. 4A). Notum with central portion uniformly dark brown. Genital fork of male with a single subquadrate inner basal lobe ending in several spurs (Fig. 3B)............................................ 2
2. Long apical ventral bristles of pedicel black. Mid and hind femur distinctly marked with broad white and dark bands (Fig. 2C). Upper margin of parafacial dark, contrasting with orange lower part of orbital strip. Genital fork of male with basal lobe broad and undivided apically, with multiple spurs (Fig. 3B). Minor spermathecal duct of female much less than half as long as major duct (Fig. 3D)........................................................... Systellapha ornatifemur new species
– Long apical ventral bristles of pedicel golden. Mid and hind femur weakly banded, with dark bands much narrower than pale parts of femora (Fig. 4B). Upper margin of parafacial similar in colour to dark lower margin of orbital strip (Fig. 4A). Genital fork of male with basal lobe shallowly divided apically, one part with a single spur and the other with multiple spurs (Fig. 4E). Minor spermathecal duct of female more than half as long as major duct (Fig. 4C)...... Systellapha ornatithorax Enderlein
description: Published as part of Marshall, Stephen A., 2020, Revision of the genus Systellapha Enderlein (Micropezidae, Taeniapterinae), pp. 369-376 in Zootaxa 4751 (2) on pages 369-371, DOI: 10.11646/zootaxa.4751.2.11, http://zenodo.org/record/3713687