Agromyza parvicornis Loew, 1869

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 parvicornis Loew

Figs 210-214

Agromyza parvicornis Loew, 1869: 49. Frick 1952a: 373, 1957: 199 [lectotype designation]; Spencer 1969: 51, 1973: 252; Spencer and Steyskal 1986b: 67.

Description.

Wing length 2.5-3.2 mm (♂), 2.6-2.9 mm (♀). Length of ultimate section of vein M4 divided by penultimate section: 0.6-0.7. Eye height divided by gena height: 2.1-3.6. First flagellomere small and rounded with minute tuft of pale apical hairs. Fronto-orbital plate projecting and anterior 1/2 of frons soft and buckled.

Chaetotaxy: Two ori (sometimes three on one side); two ors. Two dorsocentrals, sometimes with very small third seta present anteriorly. Two posteromedial setae on mid tibia.

Colouration: Body mostly dark brown with orange tint, first flagellomere brown with base orange (more extensive on inner surface); frons brownish orange with ocellar triangle, posterior margin and fronto-orbital plate to level of anterior or posterior ors dark brown, sometimes dark laterally along entire margin of eye; lunule yellowish; parafacial beige and gena (excluding ventral margin) light brown; halter white; fore knee and tarsus yellowish. Calypter white with hairs light brown; uncommonly dark brown.

Genitalia: (Figs 210-214 ) Surstylus visible laterally as small lobe; inner surface with more than a dozen tubercle-like setae. Hypandrium and postgonite as described for A. bispinata . Halves of basiphallus converging to base where both sclerites are fused to each other and phallophorus; with internal fold past midpoint and apices converging as broad triangular lobes. Distiphallus of " Agromyza nigripes -type" (capsule-shaped with subbasal opening for entry of ejaculatory duct, pronounced dorsobasal collar, and medial convolution); base of distiphallus narrow, distal portion broadly rounded, widest subapically and with internal spinulose processes. Ejaculatory apodeme well-developed with central rib visible near base; blade pale.

Hosts.

Poaceae - Echinochloa crus-galli , Panicum miliaceum , Zea mays and probably other cereals ( Spencer and Steyskal 1986b).

Distribution.

Canada: BC, ON, QC ( Zhu et al. 2004). USA: "Widespread, present in most states" ( Frick 1959). Argentina, Cuba, Guadeloupe, Puerto Rico, Dominican Republic, Saint Vincent ( Valladares 1998; Martinez and Etienne 2002).

Type material.

Lectotype: USA. DC [not given]: "Loew coll.", Agromyza parvicornis m. (1♂, MCZ).

Material examined.

Canada. BC: Milner , 12.vii.1953, G.J. Spencer, CNC352949 (1♂, CNC), ON: Ottawa , Fletcher Wildlife Gardens , 45°23'7"N, 75°42'11.01"W, 9.vi.2013, O. Lonsdale, CNC1144190 (1♂, CNC), Ottawa, 8.vii.1925, F. Ide, CNC352950 (1♂, CNC), Point Pelee, 8.ix.1954, C.D. Miller, CNC352954, CNC352955 (2♀, CNC), Simcoe, 26.vi.1939, G.E. Shewell, CNC352952 (1♂, CNC), 29.vi.1939, CNC352953 (1♂, CNC), St. Lawrence Is. Nat. Park, Grenadier I. Centre, 26.vi.1975, H.C.W. Walther, Code 1-2406-25, CNC352951 (1♂, CNC), Picton, 10.vii.1970, J.F. McAlpine, CNC353093 (1♂, CNC), QC: Ile de Montreal, 17.vi.1966, Beaulieu, CNC352956 (1♀, CNC) . USA. AZ: Sunnyside Canyon , Huachua Mts. , 9.vii.1940, D.E. Hardy (1♂, USNM), DE: Wilmington, 31.vii.1951, D.F. Bray (1♂, USNM), Sussex Co., Dewey Beach , 21.xiii.2003, sweeping, K. Bennett (1♂, UDCC), IN: Lafayette 13.[?].1915, J.M. Aldrich (1♀, USNM), MA: Concord , vii.1960, E.H. Wheeler, reared ex. Zea mays (2♂ 3♀, USNM), Franklin Co. , Northfield , 276 Old Wendell Rd. , 42°38'48.74"N, 72°25'32.15"W, 31.viii.2017, C.S. Eiseman, Zea mays , em. 2-23.vi.2018, #CSE4580, CNC1135703-1135712 (5♂ 5♀, CNC), MD: Montgomery Co. , Colesville, Malaise trap, W.W. Wirth, 7.viii.1975 (1♀, USNM), 14.vi.1973 (1♂, USNM), 20.viii.1975 (1♂, USNM), Bethseda, 6.viii.1967, G. Steyskal (1♂, USNM), Colesville, 24.vii.1974, W.W. Wirth (1♂, USNM), 4mi SW of Ashton, Malaise trap, G.F. and J.F. Hevel, 3.ix.1981 (1♂, USNM), 1.ix.1981 (2♂, USNM), NY: L.I. Veg. Res. Fm, Riverhead, at light, 1-7.viii.1938, 30.viii.1938, 7-20.viii.1938, CNC352957, CNC352958, CNC352959, CNC352960, CNC352961, CNC352962, CNC352963, CNC352964, CNC352965, CNC352966, CNC352967, CNC352968 (11♂ 1♀, CNC), TN: Nashville, G.G. Ainslie, Webster No. 9467C (1♂ [with puparium], USNM), VA: Chain Bridge, 14.v.1924, J.R. Malloch (1♀, USNM) .

Comments.

Agromyza parvicornis and A. proxima are highly similar in appearance and develop in some of the same plant genera, and can only be reliably differentiated on the basis of the relative width of the distiphallus and length of the basiphallus. It is possible that A. proxima represents a less common eastern morphological variant of the other, but in the absence of corroborating evidence, these two are maintained here as separate.

Figures

Figures 210 - 215. Agromyza parvicornis Loew 210 wing 211 external male genitalia, left lateral 212 hypandrium and postgonite, ventral 213 hypandrial complex, left lateral 214 phallus, ventral 215 Agromyza proxima Spencer, male holotype phallus, ventral.