Agromyza isolata 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 isolata Malloch

Figs 188-192

Agromyza isolata Malloch, 1913: 306. Frick 1952a: 373; Spencer and Steyskal 1986b: 264; Eiseman and Lonsdale 2018: 11.

Agromyza albitarsis Meigen. Misidentification. Frick 1959: 353.

Agromyza populoides Spencer, 1969: 52. Spencer and Steyskal 1986b [synonymy].

Description.

Wing length 2.3 mm (♂), 2.5-2.7 mm (♀). Length of ultimate section of vein M4 divided by penultimate section: 0.7. Eye height divided by gena height: 4.8-7.5. First flagellomere small and rounded; without pale tuft of apical hairs. Ocellar triangle only indicated laterally as subshiny regions.

Chaetotaxy: Two ori; two ors. Four strong dorsocentrals, one presutural. Mid tibia with one posteromedial seta.

Colouration: Setae golden-brown, distinct from scutum. Scutum with brownish grey pruinosity. Calypter margin and hairs white (brown in Agromyza isolata holotype). Body predominantly brown with halter white; base of first flagellomere and most of pedicel distinctly orange, entirely dark in Agromyza isolata holotype; BC, CA, and CO material with first flagellomere dark, with basal margin slightly lighter; tarsi, tibiae (hind tibia brownish medially) and apices of femora yellow. Wing veins light brown.

Genitalia: (Figs 188-192 ) Surstylus broad, not distinct from epandrium and with a number of medial tubercle-like setae along inner-distal margin on posterior 1/2. Hypandrium relatively narrow with long, tapered tip. Postgonite small and dome-like. Phallophorus elongate and produced on left side, fusing with single sclerite of basiphallus. Basiphallus short, shallowly curved and restricted to dorsal surface. Mesophallus curved in cross-section, dark, and with long, bifid, tapering “tail”, with bases either separated or fused; distiphallus short, dark, and cap-like. Ejaculatory apodeme relatively small, blade pale.

Host.

Salicaceae - Populus spp., Salix spp. ( Eiseman and Lonsdale 2018).

Distribution.

Canada: AB, BC*, ON, NS*, QC, SK. USA: CA, CO, MN [leaf mine only], PA, VA*, VT, WA.

Type material.

Holotype [ Agromyza isolata ]: USA. CA: Eureka, “22.5”, H.S. Barber (1♀, USNM; type No. 17573).

Holotype [ Agromyza populoides ]: Canada. SK: Regina, em. 23.viii.1965, [ex leaf mine on Populus deltoides ♀ X P. balsamifera ♂ (Spencer, 1969)], ex Gracillarid sp., RRD W65, Ex 2616(10), G.N. Still (1♂ [with puparium], CNC).

Paratypes examined

[ Agromyza populoides ]: Canada. ON: Grand Bend, 20.vii.1939, G.E. Shewell, CNC352879 (1♂, CNC), Ottawa, em. 28.vii.1967, mine Pop. Bals. 10.vii.1967, CNC352880 (1♀ [with puparium], CNC), SK: same data as holotype CNC352875-352878, CNC352881-CNC3528884 (4♂ 4♀ [seven with puparia], CNC).

Additional material examined.

Canada. BC: Terrace , grass, clover and buttercups, 7.vi.1960, R. Pilfrey, sweeping, CNC353092 (1♂, CNC), Wasa Lk., em. 29.vii.1959, “59-6779-01”, " Populus trichocarpa ", “R’rd”, CNC353083, CNC353084 (2♂ [with puparia], CNC), NS: S. Harbour Bch., PG962943 , 6.vii.1983, J.R. Vockeroth, CNC353091 (1♂, CNC), ON: Grand Bend, 20.vii.1939, G.E. Shewell, CNC353089 (1♂, CNC), Ottawa, 15.ix.1997, J.R. Vockeroth, CNC353090 (1♂, CNC), 16.ix.1952, CNC353088 (1♀, CNC) . USA. CO: Doolittle Ranch , Mt. Evans , 2987 m, 3.viii.1961, C.H. Mann, CNC353085 (1♂, CNC), J.G. Chillcott, CNC353087 (1♀, CNC), Summit L. Flats, Mt. Evans , 3901 m, 24.vii.1961, C.H. Mann, CNC353086 (1♂, CNC), VA: Falls Church, reared 25.v.1916, Populus , host: underside tentminer, J.J. deGryse (1♂ 2♀, USNM), VT: Chittenden Co., South Burlington , Winooski Gorge, 29.vi.2014, ex. Populus tremuloides , em. 15.vii.2014, C.S. Eiseman, #CSE1176, CNC384839-384841 (3♂, CNC), Chittenden Co., Williston, Mud Pond, 28.viii.2016, C.S. Eiseman, Populus grandidentata , em. 18-19.ix.2016, #CSE3000, CNC654500-654504 (2♂ 3♀, CNC) .

Figures

Figures 188 - 192. Agromyza isolata Malloch, male genitalia 188 external genitalia, left lateral 189 ejaculatory apodeme 190 hypandrium and postgonite, ventral 191 hypandrial complex, left lateral 192 phallus, ventral.