Japanagromyza Sasakawa, 1958

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

Japanagromyza Sasakawa

Japanagromyza Sasakawa, 1958: 138. Type species: Agromyza duchesneae Sasakawa, 1954, by original designation. Spencer 1969: 62; Spencer and Steyskal 1986b: 53; Lonsdale 2013: 445.

Geratomyza Spencer in Spencer and Stegmaier 1973: 140. Spencer 1984 [synonymy].

Japanagromyza is species-poor in North America north of Florida, but the species J. viridula (Coquillett) is relatively abundant from the east coast to Alberta, Kansas and Arizona, and the unusual J. rutiliceps (Melander) is known from Montana to California. The genus, which was redefined in Lonsdale (2013), has one pair of acrostichal setae and/or a lateromedial seta on the mid tibia. Agromyza also has developed acrostichal setae, but it differs in having a stridulatory file. Those Japanagromyza without acrostichals are superficially similar to Melanagromyza , but species in the latter genus have a longer ocellar triangle, more pronounced fronto-orbital plates, and often dorsally setose eyes.

The majority of species occurring in the New World can be characterised as follows: colour black (or with iridescence); only two pairs of widely spaced dorsocentrals; knob of halter white (base of knob and stem sometimes variably brown, and occasionally entirely dark, as in J. brooksi Spencer from Ontario); fore tibia with lateromedial seta (absent in J. brooksi and a number of non-Nearctic species); surstylus often long and narrow; male cercus very large and often bearing large tubercle-like setae (similar structures are found in some Agromyza ); hypandrium with long, narrow, ventrally curving apodeme apically; phallus long, narrow and clear (morphology much more varied globally), and with ejaculatory apodeme sometimes very thin or atrophied. The unusual J. rutiliceps (Melander) from the western United States differs in most of these features, and its placement is uncertain.