Pyrgotomyia Hendel, 1934

Korneyev, V. A., 2012, Revision of the genus Pyrgotomyia Hendel (Diptera: Pyrgotidae), African Invertebrates 53 (1), pp. 187-187 : 188-190

Genus Pyrgotomyia Hendel, 1934

Pyrgotomyia: Hendel 1934: 154 ; Vanschuytbroeck 1963: 23; Steyskal 1980: 560. (Type species: Pyrgotomyia ciliata Hendel, 1934 , by original designation.)

Metropina Enderlein, 1942: 108 ; Vanschuytbroeck 1963: 23; Steyskal 1972: 5; 1980: 559. (Type species Metropina temporalis Enderlein, 1942 , by original designation.) Syn. n.

Diagnosis: Species of Pyrgotomyia can be recognized from the other Old World Pyrgotini by a combination of the following: face oblique, concave without medial carina; gena with large subocular sclerite; palp short oval; lateral vertical seta lacking; presternum simple saddle-like, without finger-like lobes; mesonotum with 4–6 dorsocentral setae (including 1 or 2 presutural), 2 pairs of scutellar setae; wing narrow with dorsal surface of vein R 4+5 setulose over all its length, and very short posteroapical lobe of cell bcu; femora without long or thickened setae; oviscape simple, slightly curved dorsally and densely setulose at its apex but bearing no sclerotized hooks; elongate, apically barbed, arrow-like aculeus in female; posteriorly directed finger-like surstyli in male.

Pyrgotomyia shares such characters as concave face without medial carina, short rounded palp, more than 2 dorsocentral setae, posteriorly directed surstyli of male, apically setulose oviscape and arrow-like aculeus with Gelomyia Hendel, 1908, Paragelomyia Hendel, 1933 and Trichempodia Enderlein, 1942 ; these characters apparently are synapomorphies of these four taxa. Pyrgotomyia readily differs from them by the long pedicel and flagellomere 1, and at least this character is a synapomorphy supporting its monophyly.

Superficially similar species of the genera Euphya Wulp, 1885 and Eupyrgota Coquillett, 1898 (the spinifemur group of species), which share the concave face without carina, long antenna, lacking lateral vertical seta and similarly slender appearance, clearly differ from Pyrgotomyia by the presence of two ventrolateral rows of short spurious setae on the femora, elongate bar-like palp, bare vein R 4+5 and only 2 dorsocentral setae.

Description:

Slender flies of moderate size (wing length 4.0– 6.5 mm) of yellow or yellow-and-brown body coloration; wings with brown or pale brown subapical crossband and faintly darkened area along apical portion of costal vein.

Head slightly longer than or as long as high, and wider than long and high; short setose; ocelli absent and ocellar triangle very poorly defined or absent; parafacial bare,

with large subocular dilation; face concave, without facial carina, with lateroventral corner slightly produced anteriorly beyond facialium and visible in profile; supraclypeal sclerite moderately high (0.33× as high as face), poorly separated from face; lateral vertical seta indistinguishable; antenna as long as face, flagellomere 1 micropubescent rounded to almost acute apically, as long as or slightly longer than pedicel; arista micropubescent, 2-segmented; palpus wide and short, 0.7× as long as flagellomere 1, 1.7–1.9× as long as wide, rounded; labellum 0.7× as long as oral cavity; 1 proclinate or lateroclinate orbital seta 0.5–0.7× as long as, and 1 ocellar and 1 postocellar setae 0.7–1.1× as long as numerous (8–10) strong irregular seta-like setulae in anterior portion of frons; 1 medial vertical as long as flagellomere 1, lateral vertical seta lacking or indistinguishable from postocular and occipital setulae; presternum simple saddle-like without projected lobes, with 2–4 pairs of fine setulae; postpronotal lobe with 10–14 setulae and 0–1 seta; proepimeron slender, with 2–5 tiny setulae; mesonotum shining or subshining, non-microtrichose, sparsely and short setulose on sides, with 1–7 moderately long presutural and 2–4 postsutural setulae or setae forming regular row; presutural supra-alar and prescutellar acrostichal setae absent; scutellum with 2 pairs of setae; 1 anepisternal, 1 anepimeral and 1 katepisternal seta; wing moderately narrow, 2.7–2.9× as long as wide, with humeral and subcostal breaks; costa reaching medial vein; Sc straight, narrowly broken before costa; vein R 2+3 with (rarely without) spurious (“stump”) vein; vein R 4+5 setose over whole length; Cu 2 reaching wing margin; haltere yellow; coxae and trochanters sparsely setulose without brushes of combs of setae; femora and tibiae uniformly short setulose, fore and hind femora dorsally with 1 or 2 short and fine setae hardly distinguishable from setulae; female mid femur without bare femoral organ; hind tibia with sub-basal constriction; hind tarsi in both sexes almost symmetrical, hind tibia and basal tarsomere apicoventrally with combs of dense setulae on medial surfaces; empodium short microtrichose; syntergite 1+2 not narrowed at middle; female preabdominal sternites moderately narrow, conspicuously widening from 2 to 6, each with 2 groups of setae and setulae separated by bare medial area; oviscape narrow, almost cylindrical, curved dorsally, as long as or longer than preceding abdominal tergites, its apex with row of moderately long setae around its perimeter, often with longer and somewhat curled setae on dorsal side; apex without papillae, hooks, spinules or taenia-like structures on eversible membrane, except rudimentary ventromedial and ventro-lateral lobes in P. callosa sp. n. and P. stuckenbergi sp. n.; aculeus short (nearly as long as oviscape width in its medial portion), flattened dorsoventrally, with wider, bulky base and narrow, often barbed apex; 3 oval, smooth spermathecae; male abdomen elongate oval, not periolate, sternites 3–4 very narrow, linear, setulose, sternite 5 almost equal-sided triangular; sternite 8 setulose, hypandrium narrow, with gonites flap-like, microtrichose; phallapodeme narrow, vanes separate; ejaculatory apodeme fan-shaped; epandrium and surstyli densely covered with microscopic setulae mounted on small papillae, but without setae; lateral (outer) surstylus flat, long and broadly oval, directed posteriorly; medial (inner) surstylus short, without prensisetae; phallus long, bare; glans without filaments of acrophallus, with single tubular sclerite of praeputium.

Distribution: The genus is restricted to the Afrotropical Region. Five species are recognized in this paper to occur in the mainland Afrotropical Region from Ivory Coast in the west to Ethiopia in the east and South Africa in the south.

Remarks: Pyrgotomyia has a well developed subocular sclerite (assumed synapomorphy with almost all Afrotropical genera except Tephritopyrgota Hendel, 1914 and allied Tylotrypes Bezzi, 1914 , Pyrgotina Malloch, 1929 , and Rhagostira Enderlein, 1942 ) and belongs to the group of genera with three or more dorsocentral setae, elongated posteriorly directed lateral surstyli (possible synapomorphies with Geloemyia , Parageloemyia , Trichempodia and Porpomastix Enderlein, 1942 ), an arrow-like subapically barbed or extended aculeus (possible synapomorphy with Geloemyia , Parageloemyia and Trichempodia ) and setulose vein R 4+5 (possible synapomorphy with most species of the three latter genera except Parageloemyia wonjuensis Kim & Han, 2001 ); setulae on R 4+5 are not found elsewhere in the tribe Pyrgotini . Species of Pyrgotomyia share the long antenna (pedicel and flagellomere 1 long), long oviscape, and eversible membrane of the ovipositor with rudimentary (or without any) sclerotized structures, and I consider these characters to support monophyly of the genus. Possible phylogenetic relationships of it and related genera are beyond the scope of this paper and will be considered elsewhere (Korneyev, in prep.).

Vanschuytbroeck (1963) compared Pyrgotomyia and Metropina based on descriptions alone and one specimen of Metropina nigra Vanschuytbroeck, 1963 erroneously placed there (synonym of Eupyrgota spinifemur Hendel, 1934 , see Korneyev 2006); the differences he noted were between Pyrgotomyia and Eupyrgota , except the presence or absence of the postpronotal (=humeral) seta, which is variable in species of the genus Pyrgotomyia , and of no taxonomic value.

Enderlein (1942) separated Metropina and Pyrgotomyia based on chaetotaxy characters, which are considered variable in this study.

Metropina temporalis , the type species of the nominal genus Metropina is found to be very similar or possibly identical to Pyrgotomyia ciliata , the type species of Pyrgotomyia (see below). I therefore consider these generic names to be synonyms.

Known females of Pyrgotomyia species show no essential characters to associate them with the nominal species based on males, except when both sexes were collected together or in an area where only one species is known to occur. For this reason, P. ciliata based on the male is not considered to be a synonym of another nominal species based on female(s). As further access to more extensive material could bring up differences between males, I formally do not consider P. ciliata to be a nomen dubium.