Pegomya provecta ( Villeneuve, 1923 )

Michelsen, Verner, 2009, Taxonomic revision of the Pegomya meridiana species group (Diptera: Anthomyiidae) including natural enemies of invasive Hypericum spp. (Clusiaceae), Zootaxa 2299, pp. 29-43 : 35-39

2. Pegomya provecta ( Villeneuve, 1923)

Figs. 13–23 .

Chortophila (Phorbia) provecta Villeneuve 1923: 95 .

Chortophila provecta Villeneuve ; Séguy 1923: 132, fig. 205d.

Description. Size. Small; wing length (2.7–)3.2–4.3(–4.6)mm.

Male. Head (except lower frons to varying extent ochre yellow in teneral individuals), body and legs brownish black to black, except tibiae sometimes ochre brown, covered in dense ash-grey dusting infuscated with brown on upper parts of thorax and abdomen. Antenna black except scape and pedicel ochre brown; prementum mat, covered in thin dusting. Mesonotum with pattern of three darker stripes, those along dorsocentral setal rows very narrow; abdomen with a mid-dorsal dark stripe widened towards fore margins and falling short of hind margins of tergites II–V. Wing and calypteres dark brown infuscated; knob of halter yellow. NB: Males from Turkey and Uzbekistan are lighter greyish in appearance than males from Europe by reduced brown tinge on body and wings.

Frons at narrowest point 1.2–2.0 times as wide as anterior ocellus; moderately narrow parafrontals at this point contiguous to distinctly separated by a frontal stripe markedly widened downwards. Orbital- and interfrontal setulae absent, frontal setae 3–4 increasing in length downwards. Face short, in profile lying well behind fronto-parafacial angle; parafacial inflexed on lower part, in middle about 0.7 times as wide as postpedicel; gena in profile broad, convex at lower margin, with setae arranged in single row. Postpedicel about 1.7 times longer than broad, rounded apically; arista with short pubescence. Proboscis short, unremarkable; palpus longer than prementum.

Mesonotal ground-setulae sparse, absent between dorsocentral rows. Rows of presutural acrostichals a little closer to each other than to adjacent dorsocentral rows; about 3 pairs of presutural acrostichals, middle pair slightly enlarged. Lateral posthumeral seta long; prealar seta fully half to three-quarters length of posterior notopleural seta, always discernible from mesonotal ground setulae. Proepisternals 2, proepimerals 2–3; katepisternals 1+2. Vein C setulose ventrally on at least basal two-thirds, entirely bare dorsally. Lower calypter almost same size as upper calypter.

Fore tibia with 1 p-seta; mid tibia with 1 ad-, 1 pd- and 1 p-seta; hind tibia with 1 av-, 2(–3) ad- and 2 pdsetae. Mid femur without av-setae but with 3–6 pv-setae on basal half; hind femur with short av- and pv-setae on basal half and some stronger av-setae on distal half.

Abdomen relatively short, depressed except for strongly thickened caudal segments. Tergites III–V without discal setae. Tergite VI bare; spiracles VII absent ( Fig. 15 ). Sternite V ( Figs. 13, 14 ) and genitalia ( Figs. 16– 19 ) distinctive.

Female. Apart from primary sexual differences very similar to male, but different as follows: Frontal stripe black on upper half, orange-yellow on lower half. Thorax and abdomen covered in rather dense ashgrey dusting; faint pattern of narrow light brown striping usually visible on mesonotum; abdomen without dark mid-dorsal stripe or dark subshine. Wing faintly ochre brown tinged; calypteres whitish; knob of halter yellow. Frons broad, parallel-sided with frontal vitta about three times as wide as each parafrontal, without pair of crossed setae or setulae; parafrontal with 2–3 orbital setae followed by 2–3 frontal setae. Abdominal tergite V barely longer than tergite IV; in addition to spiracles V, it even accommodates forwardly displaced spiracles VI at its lateral margins (as in P. meridiana , Fig. 9 ). Oviscapt ( Figs. 20–22 ) in most respects in agreement with that of P. meridiana ( Figs. 10–12 ), but (1) spiracles VII are absent from tergite VI, (2) epiproct, hypoproct and cerci each with a pair of short setae, (3) cerci slightly convex, not so blade-like; and (4) hypoproct less convex in lateral view. Three spermathecae small, globular ( Fig. 23 ).

Material examined. CZECH REPUBLIC [ ZMUC]: Kunice–Vrchy, 49.56N 14.42E, 450m, edge of mixed forest, 3 males 11.vi.1983 (M. Barták). DENMARK [ ZMUC]: F: Funen, Ørritslev Skov, 55.30N 10.26E, <10m, 1 male 2.vi.1960 (A. Michelsen); LFM: Falster, Bøtø, 54.38N 11.57E, <10m, 1 male 3.vi.1984 (S. Andersen); NEZ: Zealand, Boserup Skov, 55.40N 12.02E, <10m, 1 male 6.vi.1981 (V. Michelsen). UZBEKISTAN [ ZMUC]: Aman-Kutan, 39.19N 66.55E, 1300m, pasture, 69 males, 6 females 23.v.1989 (M. Barták). TURKEY [ ZMUC]: Nevsehir: Avanos–Ürgüp area, 38.40N 34.50E, 1000–1050m, 14 males, 1 female 4–6.v.1993 (V. Michelsen); Izmir: Samsun Daġı, 37.39N 27.02E, <200m, 1 female 24–26.iv.1993 (V. Michelsen).

Other material (teste D.M. Ackland). SWEDEN [Coll. D.M. Ackland]: Torne Lappmark: Abisko, Mt. Nuolja, meadow, 800m, 1 male 27–29.vii.1993 (A.C. Pont).

Distribution. A local, rarely collected species with a distribution in western Eurasia that largely coincides with that of P. meridiana . EUROPE: Czech Republic ( Meixnerová & Rozkošný 1999), Denmark ( Petersen 2001); France ( Villeneuve 1923); Germany ( Hennig 1973b); Great Britain ( Hennig 1973b); Sweden. NEAR EAST: Turkey. CENTRAL ASIA: Uzbekistan. Presently recorded for the first time from Sweden, Turkey and Uzbekistan.

Biology. Nothing is known, but as a member of the Pegomya meridiana species group larval development of P. provecta may expectedly take place in seed-capsules of Hypericum . However, the surprising record from Torne Lappmark, the northernmost province of Sweden lying far north of the distribution range of Hypericum , suggests that the species exploits seed-capsules of some other host plant, or is able to live on both Hypericum and some alternative host plant.

Figures

FIGURES 13 – 19. Pegomya provecta (Villeneuve), male terminalia. 13, 14. Sternite V. 15. Asymmetrical pregenital sclerites of segments VI – VIII showing spiracles VI (arrows). 16, 17. Hypopygium. 18. Pre- and postgonites. 19. Phallus. Same scale.

FIGURES 20 – 23. Pegomya provecta (Villeneuve), female terminalia. 20. Oviscapt, lateral. 21. Distal part of same, dorsal. 22. Oviscapt, flat-mounted. 23. Spermatheca and duct. Same scale. Abbreviations: ce = cerci, ep = epiproct, hy = hypoproct, VI – VIII = abdominal segment numbers.

FIGURES 9 – 12. Pegomya meridiana (Villeneuve), female terminalia. 9. Abdominal segments V and VI, right half in internal view showing spiracles V – VII. 10. Oviscapt, lateral. 11. Distal part of same, dorsal. 12. Oviscapt, flat-mounted. Same scale. Abbreviations: ce = cerci, ep = epiproct, hy = hypoproct; sp = spiracle; V – VIII = abdominal segment numbers.