Agromyza tacita 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

Agromyza tacita Spencer

Figs 225-231

Agromyza tacita Spencer, 1969: 59. Spencer and Steyskal 1986b: 66.

Description

(Fig. 225 ). Externally as described for A. bispinata except as follows: Wing length 2.3-3.3 mm (♂). Length of ultimate section of vein M4 divided by penultimate section: 0.5-0.8. Eye height divided by gena height: 2.7-4.8. Small additional ori present in male with five spines on surstylus. First flagellomere sometimes paler with orange tint or predominantly orange with distal 1/2 infuscated; always enlarged in male. Postpronotum sometimes light brown or with orange tint. Wing veins brown to yellow. Fore tibia of MD male yellow with centre brownish.

Genitalia: (Figs 226-231 ) Surstylus fused to epandrium, easily viewed laterally, with dark anterior lobe and dark pronounced protuberances at base of marginal spines (three to five in number). Hypandrium, postgonite and ejaculatory apodeme as described for A. bispinata . Left sclerite of basiphallus overlapping base of right sclerite, which is fused to phallophorus; both halves with lateromedial membranous projection, and with weak connection to incurved distal section. Distiphallus of " Agromyza nigripes -type" (capsule-shaped with subbasal opening for entry of ejaculatory duct, pronounced dorsobasal collar, and medial convolution); ventral curve with truncated sclerotised elbow; distal section with bulging, internally spinulose medial section.

Variation: Dissected paratype with two spines on surstylus (as in A. bispinata ), but surstylus and remaining genitalia otherwise identical to holotype.

Variation: female paratypes: Wing length 2.9-3.1 mm. Length of ultimate section of vein M4 divided by penultimate section: 0.4. Eye height divided by gena height: 8.7-11.8. First flagellomere smaller, ovate; base always orange, reminder orange to brown. Anterior 1/2 of frons sometimes orangish.

Host.

Unknown - likely Poaceae ( Spencer and Steyskal 1986b).

Distribution.

Canada: AB*, MB[?], NB*, ON, QC. USA: MD*, MO, NH*, NY*, UT*, VA*.

Type material.

Holotype: Canada. ON: Ottawa, 17.vi.1946, G.E. Shewell, CNC352973 (1♂, CNC).

Paratypes: Canada. MB: Int. Peace Gardens, Turtle Mtn. For. Res., 7.viii.1958, J.G. Chillcott, CNC Type No. 10355, CNC352975 (1♀, CNC), ON: Ottawa, 15.vii.1957, J.E.H. Martin, CNC Type No. 10355, CNC352977 (1♀, CNC), 20.vi.1957, J.G. Chillcott, CNC Type No. 10355, CNC352974 (1♂, CNC), QC: Hull, 5.vi.1959, J.R. Vockeroth, CNC Type No. 10355, CNC352976 (1♀, CNC), Old Chelsea, summit of King Mt., 350 m, 11.vi.1959, J.R. Vockeroth, CNC Type No. 10355, CNC352978 (1♀, CNC).

Additional material examined.

Canada. AB: Elkwater L., 21.vii.1956, O. Peck, CNC353101 (1♂, CNC), NB: Kouchibouguac N.P., 11.vii.1977, J.F. McAlpine, Code-6035C, CNC352990-352992 (3♂, CNC), 12.vii.1977, J.F. McAlpine, Code-6040H, CNC352989 (1♂, CNC), 13.vii.1977, G.A. Calderwood, Code-5599I, CNC352993 (1♂, CNC), 30.vi.1977, J.R. Vockeroth, Code-5456V, CNC352986, CNC352987, CNC352981-352985 (7♂, CNC), 6.vii.1977, G.A. Calderwood, Code-54900, CNC352988 (1♂, CNC), 9.vii.1977, J.F. McAlpine, Code 6024R, Code-6024R, CNC352979, CNC352980 (2♂, CNC), ON: Ottawa, on leaf of Philadelphus coronarius , 13.vii.1959, J.R. Vockeroth, CNC353100 (1♂, CNC) . USA. MD: Plummers Isl. , 14.vi.1913, R.C. Shannon (1♂, USNM), NH: Jefferson Notch , 30.vii.1961, creek margin, W.W. Wirth (1♂, USNM), NY: Bear Mt. , 31.v.1941, A.L. Melander (1♂, USNM), UT: Cache Co., Green Canyon, 23.vii.1964, Malaise trap, W.J. Hanson (1♂, USNM), VA: Shenandoah, Big Meadows, 3.vii.1939, A.L. Melander (1♂, USNM), Fairfax Co., Dead Run, 9.vi.1915, R.C. Shannon (1♂, USNM) .

Comments.

See comments for Agromyza bispinata . The female paratypes of A. tacita cannot be confidently assigned to this species, which is mostly defined by male genitalic characters, and their placement should be re-evaluated when the boundaries of species in the A. bispinata complex can be better delimited.

Figures

Figures 225 - 235. 225 Agromyza tacita Spencer, wing 226, 227 A. tacita, external genitalia (New Hampshire male) 226 left lateral 227 ventral 228 - 231 A. tacita, genitalia (Plummers Island male) 228 external genitalia, ventral 229 phallus, ventral 230 phallus, left lateral 231 hypandrium and postgonite, ventral 232 - 235 A. echinalis Lonsdale, sp. nov., male holotype genitalia 232 external genitalia, ventral 233 external genitalia, left lateral 234 phallus, ventral 235 phallus, left lateral.