Pegomya granadensis Ackland, 1977

Michelsen, Verner, 2008, The Palaearctic species of the Pegomya terminalis species group (Diptera: Anthomyiidae), with descriptions of two new species, Zootaxa 1781, pp. 31-46 : 34-36

Pegomya granadensis Ackland, 1977

Figs. 1, 3, 5 , 8–13 , 14, 15 .

Pegomya granadensis Ackland, 1977: 198 , figs. 5–8.

Description. Small to medium-sized (WL 4.0–6.0mm; n=15).

Male. Colour: Head, body and appendages black, covered in dense ash-grey dusting. Prementum shiny, only with traces of dusting mid-basally. Disc of mesonotum with a brownish tinge and three faded dark stripes; abdomen with a very narrow but distinct mid-dorsal, dark stripe. Calypters whitish in contrast to brownish tinged wing base; haltere pale yellow.

Frons at narrowest point barely narrower that ocellar tubercle, but relatively broad parafrontalia nearly contiguous. 3–5 pairs of frontal setae reaching just above middle of frons. Orbital setulae absent, but pair of interfrontal setulae often present above frontal setae. Parafacial at narrowest point equal to basal width of fore tibia. Genal setae in single row. Aristal pubescence very short.

Presutural acrostichal rows more approximated to each other than to adjacent dorsocentral rows, consisting of 3 subequal pairs of setae and 0–3 additional setulae. Posterior posthumeral seta present but weaker than anterior posthumeral seta. Prealar seta about one-half to two-thirds as long as posterior notopleural seta. Proepimerals 2 setae, 0 setulae. Katepisternals 1 + 2 setae. Vein C distal to subcostal break without dorsal setulae. Lower calypter slightly smaller than upper calypter. Fore tibia with 1 ad (short), 1(–2) p; mid femur with pv setae on basal half; mid tibia with 0–1 a (short), 1(–2) ad, 1 pd, 1–2 p (short); hind femur with entire row of av setae and with pv setae on basal half; hind tibia with 1 av, 3 ad, 2–3 pd.

Abdomen depressed except caudally. Tergite V with both discal and hind marginal rows of setae. Tergite VI bare in front of 6–9 hind marginal setae. Sternite V in profile with angular, downward projecting lobes beset with a dense, marginal fringe of setulae. Terminalia ( Figs. 8–13 ) diagnostic, especially in respect to shape of surstyli, gonites and phallus.

Female. Colour as in male except mid-dorsal stripe of abdomen shorter and broader, formed by triangular dark markings on tergites II–IV.

Frons at narrowest point barely wider than one-third of head width. Frontal vitta about twice as wide as adjacent parafrontals, each bearing 2 reclinate and 1 proclinate orbital setae and 2(–3) parafrontal setae; frontal vitta with short but distinct pair of interfrontal setae. Posterior posthumeral seta setulose. Prealar stronger, almost same length as posterior notopleural seta. Vein C distal to subcostal break without or with a short, irregular row series of dorsal setulae.

Abdomen with tergite V bearing several erect discal setae in addition to row of hind marginal setae. Sternite V with hind marginal setae numerous, forming a distinct tuft. Distal part of depressed segment VII of oviscapt always exposed. Oviscapt ( Figs. 14, 15 ) very long, apically strongly depressed; apical margin of short cerci not forming a cutting edge.

Material examined. SPAIN: Granada [type material, ZMUC]: Rio Lanjaron near Lanjaron, 600m, 2 males 28.iv.1966 (Lyneborg–Martin–Langemark); Rio Guadalfeo, Orgiva, 300m, 1 female 19.iv.1966 (Lyneborg–Martin–Langemark); Alicante [ ZMUC]: Beniaia, stream bed, on flowering Salix , 3 males 18.iii.2007 (V. Michelsen). MOROCCO [ ZMUC]: Quezzane, 300m, 1 male 21–22.iv.1989 (Zool. Mus. Copenh. Exp.). Chechaouèn, 600m, 7 males, 1 female 22.iv.1989 (Zool. Mus. Copenh. Exp.).

Biology. An early-season species found in stream beds and other sheltered places with lush vegetation. In Morocco I have observed and collected males engaged in station-taking behaviour on shaded twigs of a small tree. In Spain I have collected males in the early spring by sweeping flowering Salix- shrubs. Immature habits are unknown, but the larva is expected to feed on horsetail ( Equisetum ).

Distribution. Apparently a western Mediterranean species, known so far from localities in southern Spain and northern Morocco.

Figures

FIGURES 1 – 5. Pegomya spp., body parts. 1. P. granadensis, frontal aspect of male head. 2. P. terminalis, frontal aspect of female head. 3. P. granadensis, female abdomen. 4. P. sp. aff. granadensis, female abdomen. 5. P. granadensis, female sternites I – V.

FIGURES 8 – 13. Pegomya granadensis, male. 8, 9. Sternite V, ventral and lateral views. 10, 11. Hypopygium, caudal and lateral views. 12. Pre- and postgonites, lateral view. 13. Phallus, lateral view. Same scale.

FIGURES 14, 15. Pegomya granadensis, female. 14. Oviscapt, flat mounted. 15. Distal part of same.