Melanagromyza Hendel, 1920

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

Melanagromyza Hendel

Melanagromyza Hendel, 1920: 114. Type species: Agromyza aeneoventris Fallén, 1823, by original designation. Frick 1952a: 375; Spencer 1969: 64; Spencer and Steyskal 1986b: 18; Lonsdale 2014: 495; Shi and Gaimari 2015: 10.

Limnoagromyza Malloch, 1920: 147. Type species: Limnoagromyza diantherae Malloch, 1920, by original designation. Frick 1952a [synonymy].

Many Melanagromyza have a noticeably metallic green, blue, or coppery sheen on the abdomen (not including the black oviscape), which is also often present on the notum, but this feature should not be used as diagnostic in and of itself as a metallic sheen is also found in a handful of other Agromyzinae . This sheen is usually very faint in these other taxa, but some Japanagromyza species, including the relatively abundant eastern species J. viridula , are strikingly green. Conversely, those Melanagromyza with little or no metallic colouration can be easily mistaken for some Euhexomyza and Ophiomyia , although dorsally setulose (not bare) eyes, a wider fronto-orbital plate and a broadly rounded clypeus will reveal their generic affiliation.

Externally, the Delmarva Melanagromyza are best diagnosed by an absence of characters found in other local Agromyzinae : there are no prescutellar acrostichals (present in Agromyza and Japanagromyza ) or a stridulatory file on syntergite 1+2 ( Agromyza ); the clypeus is usually broadly rounded (apically truncated in all Ophiomyia ), but if the anterior margin is straight, the lateral corners are rounded; the eye is usually setulose dorsally (always bare or very sparsely short-setulose in Ophiomyia ); the gena is never strongly produced anteriorly, there is never a vibrissal fasciculus, and the facial keel is never prominent if present (many Ophiomyia ).

The male genitalia are most characteristic of the genus: the basiphallus is short, symmetrical and U-shaped or ring-like; the epandrium sometimes has a small posterodistal spine behind the surstylus (not always visible in lateral view); the ventrobasal surface of the distiphallus has one pair of thin tubules flanking the mesophallus (unconfirmed in some non-Nearctic species).