Melanagromyza vernoniae Steyskal

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 vernoniae Steyskal

Figs 305-308

Melanagromyza vernoniae Steyskal, 1981: 41. Spencer and Steyskal 1986b: 23.

Description.

Wing length 3.1-3.5 mm (♂), 2.8-3.4 mm (♀). Length of ultimate section of vein M4 divided by penultimate section: 0.6-0.7. Eye height divided by gena height: 4.6-5.5. Clypeus broadly rounded. Male eye with short, scattered setulae covering dorsomedial region of eye (setulose region relatively narrow compared to M. Melanagromyza vernoniana ) that may sometimes be relatively dense; female eye virtually bare. Fronto-orbital plate slightly widened at middle, only slightly more than one quarter width of frons at widest point; subshiny; bulging anteriorly and slightly visible laterally, sometimes continuing as ring below eye. Ocellar triangle relatively narrow and parallel-sided, reaching level of posterior ori.

Chaetotaxy: Two ori with anterior seta strongly displaced anteriorly (one IN male with additional seta between standard ori that is weak on left side and well-developed on right); two ors with anterior seta slightly inclinate. Orbital setulae with up to three irregular, scattered rows, generally erect, slightly reclinate anteriorly and proclinate posteriorly and along outer row; relatively long and bushy, considerably longer than ommatrichia (more so in males). Two dorsocentral setae. Acrostichal setulae in eight irregular rows. Katepisternum with one to several short setae clustered dorsomedially. Mid tibia with two posteromedial setae.

Colouration: Body, including halter, dark brown in base colour; pedicel and scape sometimes slightly paler brown. Notum with slight bluish shine that may be slightly greenish, especially on posterior third of scutum and on scutellum. Calypter margin and hairs white. Abdomen with strong metallic green shine. MN male with abdomen blue. IN specimens with notum greenish (not blue) and abdomen greenish coppery in males and green to blue in females.

Genitalia: (Figs 305-308 ) Surstylus (entirely fused to epandrium) with relatively long, flat distal margin ~ 2/3 length of distal section of epandrium (dorsum of epandrium shallower) that is slightly produced at anterior corner; inner surface with two (posteriorly) to four (anteriorly) rows of short, thickened setae, of which a few at slightly produced corner of surstylus are elongate, although state not as exaggerated as seen in M. virens. Hypandrium extremely long and produced apically and with longitudinal basal ridge; inner lobe irregular in outline and weakly sclerotised. Metepiphallus with small spines medially and with coalescing ridges laterally. Proepiphallus V-shaped. Basiphallus U-shaped with corners at right angles and arms parallel. Mesophallus and distiphallus level at base. Distiphallus with basal section ~ 2/3 length of segment, relatively narrow, not bulging dorsally, with well-developed internal spinulose pads; ventrolateral tubules relatively long, narrow, recessed.

Host.

Asteraceae - Vernonia noveboracensis .

Distribution.

USA: DC, IN*, MN*.

Type material.

Holotype [ Melanagromyza vernoniae ]: USA. DC: 18.x.1969, D. Anderson, Vernonia noveboracensis , emg. indoors after refrigeration 19.xii.1969 (1♂, USNM).

Paratypes [ Melanagromyza vernoniae ]: USA. DC: Washington, E Bank CandO Canal nr. Ariz. Ave., reared from larva in stem Vernonia noveboracensis , D.M. Anderson, 23.i.1970 (1♂, USNM), 28.iii.1970 (2♂, USNM).

Additional material examined.

USA. DC: Washington, E Bank CandO Canal nr. Ariz. Ave., 14.x.1969, D.M. Anderson, Reared from larvae in stem Vernonia noveboracensis , 23.ii.1970 (3♀, USNM), Washington, E Bank CandO Canal nr. Ariz. Ave., 28.iii.1970, D.M. Anderson, Reared from larvae in stem Vernonia noveboracensis (1♀, USNM), IN: LaFayette, J.M. Aldrich, v-23 (1♂ 1♀, USNM), v-27 (6♂ 3♀, USNM), v-28 (1♂, USNM), iv-27 (3♂, USNM), vi-10 (1♂, USNM), vi-22 (1♀, USNM), vi-23 (1♂, USNM), vii-8 (1♀, USNM), 6-27 (1♂, USNM), MN: New Ulm, 30.v.1916, J.M. Aldrich (1♂, USNM) .

Figures

Figures 305 - 308. Melanagromyza vernoniae Steyskal, male genitalia 305 hypandrium, ventral 306 hypandrial complex, left lateral 307 phallus and proepiphallus, ventral 308 external components, left lateral.