Agromyza echinalis, Lonsdale, 2021

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 echinalis sp. nov.

Figs 232-235

Description.

Externally as described for A. bispinata except as follows: Wing length 2.5-2.6 mm (♂). Female unknown. Length of ultimate section of vein M4 divided by penultimate section: 0.6. Eye height divided by gena height: 4.2. First flagellomere always enlarged in male, broadly ovate, slightly longer than high and covered with long hairs past base. Additional ori sometimes present on one side of frons. Wing veins yellow. Antenna orange with brownish tint, mostly brownish past base of first flagellomere; frons tinted with orange; fore tibia yellow with centre brownish.

Genitalia: (Figs 232-235 ) Surstylus large and triangular with numerous long spines along inner margin and with one spine at apex; basal suture obliterated, inner surface flat and easily viewed posteriorly. Hypandrium and postgonite as described for A. bispinata . Halves of basiphallus with medial membranous process that is longer and truncated on right side. Distiphallus of " Agromyza nigripes -type" (capsule-shaped with subbasal opening for entry of ejaculatory duct, pronounced dorsobasal collar, and medial convolution); ventral curve with dark truncated elbow; ventral surface with medial longitudinal suture; sides shallowly rounded and internally spinulose subapically.

Host.

Unknown.

Distribution.

USA: MD, TN, VA.

Etymology.

Gr., referring to the characteristic spiny surstylus.

Type material.

Holotype: USA. TN: Clarksville, 13.v.1936, E.W. Howe (1♂, USNM).

Paratypes: USA. MD: nr. Plummers Isl., 6.vi.1914, R.C. Shannon (1♂, CNC), VA: Fairfax Co., Dead Run, 19.vi.1915, R.C. Shannon (1♂, USNM).

Comments.

The heavily spinulose surstylus of Agromyza echinalis is the primary defining feature that distinguishes it from other species with an enlarged first flagellomere. As in A. tacita (Figs 226-228 ) and A. hockingi (Colorado, Texas, Utah; Spencer and Steyskal 1986b: figs 411-413), the surstylus is triangular and clearly visible laterally, but these other two species have a slightly darker and more rounded surstylus with a maximum of five stout spines.

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.