Agromyza canadensis Malloch, 1913

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

Agromyza canadensis Malloch

Figs 1 , 2 , 7-10 , 175-178

Agromyza canadensis Malloch, 1913: 299. Frick 1952a: 372; Spencer 1969: 39, 1990: 198; Spencer and Steyskal 1986b: 59; von Tschirnhaus 1993: 512 [suspected to be conspecific with A. pseudorufipes Nowakowski].

Description

(Figs 1 , 2 , 7-10 ). Wing length 3.1-3.9 mm (♂), 3.3-4.0 mm (♀). Length of ultimate section of vein M4 divided by penultimate section: 0.5-0.7. Eye height divided by gena height: 4.2-7.3. First flagellomere small and rounded; pale tuft of apical hairs varies from teardrop-shaped to encompassing distal 1/3 of segment. Ocellar triangle relatively small with corners rounded.

Chaetotaxy: Three or two ori; two ors. Five dorsocentrals (sometimes small fifth seta indistinct), decreasing in size anteriorly. Mid tibia with two posteromedial setae.

Colouration: Setae brown. Body predominantly brown with yellowish tint or yellow with brownish tint, with thorax darker and halter white. First flagellomere dark brown to brown and scape and pedicel yellow to brownish; face and lunule dirty yellow in ON specimens; gena (excluding ventral margin), parafacial (excluding inner margin) and anterior margin of postgena light brown in female; postpronotum and notopleuron yellowish in part; lateral and sometimes apical margins of scutellum and postsutural scutum yellow in females and some males. Pleuron paler brown with venter darker and posterior region yellowish; metanotum yellow with brown mottling and dark brown mediotergite; males sometimes darker. Calypter margin and hairs white. Legs yellow with faint brownish tint; tarsi sometimes paler and femora sometimes slightly darker. Abdomen brownish yellow, paler in female with dorsum sometimes brownish and oviscape brown.

Genitalia: (Figs 175-178 ) Surstylus indistinct, fused to epandrium; inner surface with many small, rounded tubercle-like setae not reaching anterior corner. Hypandrium relatively narrow with apex pointed; inner lobe small, rounded and with large separate medial sclerite closely associated with postgonite. Postgonite large and flat with partial fusion to hypandrial band; with sparse hairs on outer face. Halves of basiphallus flat, wide and poorly sclerotised; apices broad, converging past internal subapical fold. Distiphallus very large, resembling a thick band with anterior and posterior margins strongly curled outwards; basal portion with small, shallow lateral sculpturing. Ejaculatory apodeme well-developed basally, but reduced, thin and pale apically.

Hosts.

Boraginaceae - Cynoglossum , Mertensia ( Benavent-Corai et al. 2005).

Distribution.

Canada: ON, QC*. USA: CA, VA*.

Type material.

Holotype: Canada. ON: Cottage Beaulieu, Beaulieu, 14.viii.1906 (1♀, USNM).

Additional material examined.

Canada. ON: Hawkeston , 28.vi.1927, C.H. Curran, CNC353079 (1♂, CNC); Mer Bleu[e], 5mi E Ottawa, 9.vi.1966, D.D. Munroe, CNC353082 (1♂, CNC), Ottawa, Montfort Hosp., 17.vii.1993, J.R. Vockeroth, CNC353074 (1♂, CNC), Ottawa, 18.viii.1924, G.S. Walley, CNC353081 (1♀, CNC), damp second-growth Acer - Betula woods, 17.viii.2000, J.R. Vockeroth, CNC353075 (1♀, CNC), 30.v.1958, J.R. Vockeroth, CNC353078 (1♂, CNC), 30.vi.1958, J.R. Vockeroth, CNC353080 (1♂, CNC); damp second-growth Acer - Betula woods, 6.viii.1996, J.R. Vockeroth, CNC353073 (1♂, CNC), QC: Burnett, 13.viii.1977, J. O’Hara, CNC353076 (1♀, CNC), Old Chelsea, 11.vi.1959, J.R. Vockeroth, CNC353077 (1♀, CNC) . USA. VA: nr. Plummers Island , 20.v.1914, R.C. Shannon (1♂, USNM), Giles Co., Ripplemead , White Riverbend Pk., 37°19'N, 80°41'W, 9.v.2006, S.A. Marshall (1♀, DEBU), Fairfax Co. , Great Falls Park, quarry, 38°59.1'N, 77°14.8'W, Malaise trap, D.R. Smith, 24.iv-2.v.2007 (4♀, USNM), 3-10.v.2007 (12♀, USNM) .

Comments.

Agromyza canadensis is highly similar to the Palaearctic A. pseudorufipes Nowakowski, especially with regards to the derived structure of the phallus. It is also a borage feeder on Myosotis , Podonosma and Trigonotis ( Benavent-Corai et al. 2005). Von Tschirnhaus (1993) suggested that the two species could be conspecific, but additional study is required.

Figures

Figures 1 - 6. Agromyza canadensis Malloch, female head 1 anterior 2 lateral 3 Phytobia setosa (Loew), wing, with detail of junction of R 1 and costa 4 Melanagromyza virens (Loew), wing, with detail of junction of R 1 and costa 5 political map of the United States and Canada 6 detail of the Delmarva states - Delaware, Maryland, Virginia and West Virginia, and the District of Columbia. Abbreviations: c, costal vein; fr orb, fronto-orbital setae; iv s - inner vertical seta; oc, ocellar seta; ori a, anterior inferior orbital seta; ori p, posterior inferior orbital seta; ors a, anterior superior orbital seta; ors p, posterior superior orbital seta; ov s, outer vertical seta; po, postocellar seta; sc, subcostal vein; vb, vibrissa.

Figures 7 - 11. Agromyza canadensis Malloch, female 7 lateral 8 detail of thorax, lateral 9 dorsal 10 detail of thorax, dorsal 11 Agromyza pseudoreptans Nowakowski, extended female postabdomen, lateral (fig. 20 from Spencer 1987). Abbreviations: 1, fore; 2, mid; 3, hind; anatg, anatergite; anepm, anepimeron; anepst, anepisternum; ap sctl s, apical scutellar seta; cx, coxa; dc s, dorsocentral seta (numbered from back); f, femur; kepst, katepisternum; ktg, katatergite; lat sctl s, lateral scutellar seta; mr, meron; mtg, mediotergite; npl, notopleuron; npl s, notopleural seta; ovsc, oviscape (fused tergite and sternite 7); pre spal s, presutural supra-alar seta; post ial s, postsutural intra-alar seta; post spal s, postsutural supra-alar seta; pprn, postpronotum; pprn s, postpronotal seta; proepst, proepisternum; sctl, scutellum; t, tibia; T, tergite; tar, tarsus; trch, trochanter.

Figures 175 - 178. Agromyza canadensis Malloch, male genitalia 175 external genitalia, ventral 176 hypandrium and postgonite, ventral 177 hypandrial complex, left lateral 178 phallus, ventral.