Cerodontha (Dizygomyza) fasciata (Strobl)

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

Cerodontha (Dizygomyza) fasciata (Strobl)

Figs 513-518

Phyllomyza fasciata Strobl, 1880: 38.

Agromyza grossicornis var. fasciata . Strobl, 1893: 135.

Dizygomyza morosa Meigen. Misidentification. Hendel 1931-1936: 90.

Dizygomyza plumbea Hendel, 1931-1936: 92. Spencer 1971 [synonymy].

Phytobia (Dizygomyza) plumbea . Groschke, 1957: 116.

Cerodontha (Dizygomyza) plumbea . (in part) Nowakowski, 1967: 645.

Dizygomyza grisea Ryden, 1952: 26. Nowakowski 1967: 645 [as synonym of Dizygomyza plumbea ]; Spencer 1971 [as synonym of Dizygomyza fasciata ]

Cerodontha (Dizygomyza) fasciata . Nowakowski, 1967: 644, 1972: 761; Spencer 1971: 153 (lectotype designation), 1976: 220; Spencer and Steyskal 1986b: 282; Benavent-Corai et al. 2005: 11.

Cerodontha (Dizygomyza) chaixiana (Groschke). Misidentification. Spencer, 1969: 115.

Description.

Wing length 2.3-2.6 mm (♂), 2.7-2.8 mm (♀). Length of ultimate section of vein M4 divided by penultimate section: 1.3-1.7. Eye height divided by gena height: 6.0-10.8. Male first flagellomere much enlarged, circular or slightly higher than long with anterodorsal margin sometimes slightly angled; covered with long, whitish hairs that end before base; female first flagellomere not enlarged or haired as for male, but with anterodorsal margin sometimes slightly angled. Arista slightly thickened on basal ¼ -1/3. Male orbital not strongly projecting, but evident along length when viewed laterally with anterior margin most prominent; female fronto-orbital plate weakly visible laterally. Lunule large, broadly semi-circular with lateral margin meeting fronto-orbital plate; slightly narrower in female. Fronto-orbital plate widest medially, not exceeding 1/5 frons width. Posterior ocelli slightly displaced.

Chaetotaxy: Two ori (anterior seta slightly shorter); two ors; sometimes with additional ors or minute anterior ori on one side. Orbital setulae in one sparse row; erect with anterior setulae slightly proclinate. Postocellar and ocellar setae subequal to fronto-orbitals. Apex of palpus sometimes with two slightly stronger setae. Four dorsocentrals, decreasing in length anteriorly, anterior dorsocentral almost 1/2 length of posterior dorsocentral. Six irregular rows of acrostichal setulae, reduced to two rows posteriorly, nearly attaining posterior margin of scutum; slightly longer posteriorly with one pair sometimes appearing as prescutellar acrostichal setae.

Colouration: Setae dark brown, paler when reflecting light. Antenna brown to dark brown with first flagellomere darker; frons dirty yellowish brown with greyish pruinosity, palest on fronto-orbital plate, region between triangle and fronto-orbital plate darker, speckled with minute brown pits; lateral margin of fronto-orbital plate darker brown and base of setae sometimes with minute brown spot; ocellar triangle dark brown, slightly larger than tubercle, confluent with dark brown margin along back of head; slightly paler triangular region surrounding ocellar triangle; dark brown spot in posterolateral corner of frons reaching base of inner vertical seta; lunule smooth, velvety greyish, sometimes slightly darker brown dorsally; clypeus and venter of gena dark brown, remainder of gena dorsally with colour and texture as seen medially on frons; face dark brown with paler regions medially and ventrally. Thorax dark brown with faint pruinosity that is thicker on notum and dorsally on pleuron; notopleuron yellowish, at least in posterolateral corner, where yellow may be more pronounced; scutum with minute light yellow spot at lateral corner of scutellum and sometimes anterior corner of postpronotum. Calypter margin and hairs yellowish white. Wing veins yellow basal to medial 1/2 of basal cells. Halter yellow. Legs dark brown; apex of fore femur light yellow for length equal to width of femur; similar faint yellowish pigment often evident on mid and hind femora with hind leg darker; tarsi paler. Abdomen dark brown.

Genitalia: (Figs 513-518 ) Epandrium with pronounced process above anus that has base constricted (absent in male from Ohio); surstylus fused to epandrium, small, directed inwards, with three stout tubercle-like setae. Subepandrial sclerite with weak transverse dorsal band and one pair of medial setae; ventral lobe dark, apically tapering and medially curved; outer margin of process minutely serrated subapically and with shallow apical point. Phallophorus with narrow process on left margin, dorsally confluent with basiphallus. Basiphallus with dorsal plate that extends along right side as downturned, pointed process mirroring single sclerite of hypophallus, which is L-shaped and narrow and paler apically; left sclerite of basiphallus dark, clavate and weakly attached to dorsobasal section. Paraphallus (one pair) clear, lobate, with weak comma-shaped sclerotisation. Mesophallus very dark, rod-shaped, narrowest basally; with complete ventral suture; distal 2/5 slightly swollen to enclose chamber, with dorsum, ventral surface and lateroventral plate better-sclerotised. Distiphallus S-shaped, divided into one pair of separate parallel tubules; darker to base with clear basal section meeting mesophallus; with small basal curve and larger apical curve both semi-circular in outline; apex slightly swollen for length equal to 2 × width. Ejaculatory apodeme with basally tapering stem with broad base; blade large, clear; sperm pump with basal mottling.

Host.

Poaceae - Poa .

Distribution.

Canada: AB, BC*, NS*, ON. USA: MA*, MD*, MI*, NC, NY*, OH*, VA*, WV*. Europe ( Papp and Černý 2016).

Type material.

Lectotype [fasciata]: Austria: Karnten: Ossiach (1♂, Coll. Strobl, Admont). [Not examined]

Lectotype [plumbea]: Austria (1♂, NMW). [Not examined]

Holotype [ Dizygomyza grisea ]: Sewden: Gotland: Fridhem, 22.vi (1♂, ZIL). [Not examined]

Material examined.

Canada. AB: Jumping Pd. Cr., 20 mi W Calgary, 28.vi.1962, K.C. Hermann, CNC480756 (1♂, CNC), BC: Atlin , 6.vii.1955, B.A. Gibbard, CNC480770 (1♀, CNC), Royston , 7.vi.1955, R. Coyles, CNC480760 (1♂, CNC), Terrace , marshy meadow, 11.vi.1960, J.G. Chillcott, CNC480740-480742 (3♂, CNC), 31.v.1960, C.H. Mann, CNC480743-480747, CNC480771-480778 (5♂ 8♀, CNC), R.J. Pilfrey, CNC480779 (1♀, CNC), 31.vi.1960, J.G. Chillcott, CNC480748-480754, CNC480780-480785 (7♂ 6♀, CNC), Zymagotitz River , 6mi W Terrace, 57 m, 20.iii.1960, R. Pilfrey, CNC480739 (1♂, CNC), NS: Kentville, 6.viii.1958, J.R. Vockeroth, CNC480757, CNC480768, CNC480769 (1♂ 2♀, CNC), ON: Dresden, 2.vii.1962, S.M. Clark, CNC480767 (1♀, CNC), Midland, swamp woods, balsam poplar, 2.v.1959, J.G. Chillcott, CNC480765 (1♀, CNC), North Gower , 14.vii.1985, D. Bell, light trap, CNC480758 (1♂, CNC), Ottawa, 14.v.1957, J.G. Chillcott, CNC480766 (1♀, CNC), swept from Sagittaria, 3.ix.1989, J.R. Vockeroth, CNC480759 (1♂, CNC), St. Lawrence Is. Nat. Par. , McDonald Is., 14.vii.1976, A. Carter, Code 4092-J, CNC480761 (1♂, CNC), St. Lawrence Is. Nat. Park, Thwartway Is., 17.vii.1976, A. Carter, Code 4133-Y, CNC480762 (1♂, CNC), St. Lawrence Is., Thwartway Is., 4.viii.1976, W. Reid, Code 4322-H, CNC480764 (1♀, CNC), Bells Corners, 5.vii.1973, F. Crombie and P. Nash, CNC480763 (1♂, CNC) . USA. MA: Concord , 17.vii.1961, W.W. Wirth (1♂, USNM), Woods Hole, vii.1918, A.H. Sturtevant (1♂, USNM), MD: Lavale, 9.v.1970, G. Steyskal (1♂, USNM), Montgomery Co., Clarksburg , Little Bennett Reg. Park, 21.ix.1990, W.E. Steiner and M.J. and R. Molineaux (1♂, USNM), Montgomery Co. , Bethseda , 4.v.1969, G. Steyskal (1♂, USNM), Montgomery Co. , 4mi SW of Ashton, 25.iv.1987, G.F. and J.F. Hevel (1♂, USNM), 28.iv.1985 (1♂, USNM), MI: Isle Royale , 3-7.viii.1936, C. Sabrosky (1♂, USNM), NC: Mitchell Co. , Roan Mtn., 1889 m, 13.viii.1957, J.G. Chillcott, CNC480755 (1♂, CNC), NY: Geneva , 28.v.1914, A.L. Melander (1♂, USNM), OH: Columbiana Co. , Beaver Creek , 40°43.8'N, 80°36.5"W, 7.vii.1976, B.A. Steinly (1♂, USNM), Stark Co. , Berlin Reservoir, 40°58.9'N, 81°06.0'W, 7.vii.1976, B.A. Steinly, sand shore, 200 net sweeps (1♂, USNM), VA: Big Meadows, 3.vii.1939, A.L. Melander (1♂, USNM), WV: Greenbrier Co. , Charmco, 6.ix.1982, G.F. and J.F. Hevel (1♂, USNM), Morgan Co., near Great Cacapon, 3.vii.1983, G.F. and J.F. Hevel (1♂, USNM), White Sulfur Springs, 16.vi.1970, G. Steyskal (1♂, USNM) .

Figures

Figures 513 - 518. Cerodontha (Dizygomyza) fasciata (Strobl), male genitalia 513 external genitalia, anterior 514 external genitalia, left lateral 515 hypandrium and postgonite, ventral 516 ejaculatory apodeme 517 phallus, ventral 518 phallus, left lateral.