Agromyza tacita Spencer

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

publication ID

publication LSID

persistent identifier

treatment provided by

ZooKeys by Pensoft

scientific name

Agromyza tacita Spencer


Agromyza tacita Spencer  

Figs 225-231 View Figures 225–235

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


(Fig. 225 View Figures 225–235 ). 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 View Figures 225–235 ) 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.


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


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

Type material.

Holotype: Canada. ON: Ottawa,, 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),, J.G. Chillcott, CNC Type No. 10355, CNC352974 (1♂, CNC), QC: Hull,, J.R. Vockeroth, CNC Type No. 10355, CNC352976 (1♀, CNC), Old Chelsea, summit of King Mt., 350 m,, 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),, 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. ,, 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,, R.C. Shannon (1♂, USNM)   .


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.














Agromyza tacita Spencer

Lonsdale, Owen 2021

Agromyza tacita

Spencer 1969