Phytomyza clematiphaga Spencer, 1969

Lonsdale, Owen, 2021, Manual of North American Agromyzidae (Diptera, Schizophora), with revision of the fauna of the " Delmarva " states, ZooKeys 1051, pp. 1-481 : 1

Phytomyza clematiphaga Spencer

Figs 760-762

Phytomyza clematiphaga Spencer, 1969: 236. Sehgal 1971 b: 361; Spencer and Steyskal 1986b: 176; Eiseman and Lonsdale 2018: 69.

Description.

Wing length 2.0-2.4 mm (♂), 2.4-2.5 mm (♀). Vein dm-m absent. Eye height divided by gena height: 2.3-3.6. First flagellomere relatively large, broad and longer than high, with shape subcircular to more subrectangular; length at most 1/3 more than height; hairs on most of segment elongate and sometimes bushy (more so towards anterior margin), with length usually not exceeding width of base of arista. Cheek distinct.

Chaetotaxy: One ori; two ors. Postocellar and ocellar setae subequal to fronto-orbitals. Four dorsocentrals decreasing in size anteriorly. Two rows of acrostichal setulae.

Colouration: Setae brown with pale shine (not dark brown to black). Head mostly light yellow; ocellar tubercle brown medially with spot extending to ocelli; fronto-orbital plate to posterolateral corner of frons around vertical setae whitish, faintly white pruinose; back of head with dark brown spot above foramen (not reaching margin); first flagellomere black; palpus brownish to brown or yellow, sometimes only darker apically. Notum light yellow with wide medial stripe between dorsocentral rows on anterior 2/3, one pair of floating intra-alar stripes near centre, and sometimes one pair of narrow, sometimes curved, postsutural supra-alar stripes; grey pruinosity evident on darker regions. Metanotum light yellow with mediotergite and venter of anatergite dark brown with greyish pruinosity. Pleuron mostly light yellow with faint grey pruinosity evident on pigmented regions; anepisternum with nearly indistinct, narrow, irregular anteroventral stripe; katepisternum with dark ventral spot that does not reach base of seta; meron mostly brown. Halter white. Calypter white. Legs yellow with distal segments of tarsi becoming more brown or brownish apically. Abdomen yellow (excluding oviscape), with dorsum brownish anterior to terminalia in male; posterior margin of tergites yellow.

Genitalia: (Figs 760-762 ) Hypandrium with two setae and haired membrane projecting from inner lobe. Postgonite cleft apically and with several outer subapical sockets and one seta. Epiphallus with broad, flat lateral arm. Halves of basiphallus broad and interlocking at base, with strong ventrobasal arm on left 1/2. Sclerotized halves of hypophallus broadly arched and well-sclerotised with apices broad and narrow, nearly meeting medially; basal 1/2 curved, stouter and darker, distal 1/2 paler, similarly curved and directed downwards at apex. Mesophallus rounded at base, longer than wide, dark and subcylindrical, fused to distiphallus; mesophallus + distiphallus as long as basiphallus. Distiphallus dark, entirely split into one pair of narrow tubules that are slightly flared apically. Ejaculatory apodeme with base and margin closest to duct dark with remainder pale to clear; sperm pump dark ventrally.

Variation: MD males differs as follows: notal stripes fused into one large irregular spot; side of scutellum brownish; tibiae and tarsi brownish; eye height divided by gena height: 2.6; wing length 1.9 mm.

Hosts.

Ranunculaceae - Clematis sp., C. columbiana , C. verticillaris .

Distribution.

Canada: AB. USA: CO, MD*, MT.

Type material.

Holotype: Canada. AB: Edmonton, em. 7.viii from leaf mine on Clematis sp., leg. 26.vii.1966, B. Hocking (1♂, CNC).

Paratypes examined.

USA. MO: 15 mi NE Polson, 26.vii.1967, Note No. 6702, S. Whitney (2♀, USNM).

Additional material examined.

USA. CO: Fremont Co., Bear Creek , Forest Rd 101, off of 49 Rd, 7.vii.2015, C.S. Eiseman, Clematis , em. 19-22.vii.2015, #CSE1728, CNC654335, CNC654336 (1♂, 1♀, CNC), MD: Colesville, W.W. Wirth, 14.vi.1977 (1♀, USNM), 18.vi.1977 (1♂, USNM), 28.v.1977 (3♂, USNM) .

Comments.

Phytomyza clematiphaga is here recorded for the first time in eastern North America in Maryland, with males and females that are slightly darker than their western counterparts. The species P. compta is also brightly coloured, but it has a much larger wing (2.8-3.8 mm); the first flagellomere is more densely long-haired; the calypter hairs, tibiae and tarsi are darker; the notum is darker, although the scutum sometimes maintains a similar, but more extensive vittate pattern; and the hypophallus and distiphallus differ.

Figures

Figures 760 - 765. Phytomyza clematiphaga Spencer, male genitalia 760 hypandrium and postgonite, ventral 761 hypandrial complex, left lateral 762 phallus, ventral 763 - 765 P. compta (Spencer), male genitalia 763 phallus, left lateral 764 ejaculatory apodeme 765 hypandrium and postgonite, ventral.