Melanagromyza virginiensis Spencer, 1986

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 virginiensis Spencer

Figs 58 , 59 , 325-328

Melanagromyza virginiensis Spencer in Spencer and Steyskal 1986b: 248.

Description

(Figs 58 , 59 ). Wing length 3.1-3.2 mm (♂), 2.8-3.3 (♀). Length of ultimate section of vein M4 divided by penultimate section: 0.6-0.7. Eye height divided by gena height: 3.7-5.9. Clypeus broadly rounded. Ocellar triangle slightly longer than wide. Fronto-orbital plate ¼ width of frons, widest near middle. Fronto-orbital plate and ocellar triangle subshiny.

Chaetotaxy: Two widely separated ori; two ors. Eye extensively pilose, with hairs sparse excluding dense dorsal patch. Orbital setulae erect to slightly proclinate, and mostly lateroclinate. Two dorsocentral setae. Acrostichal setulae in eight irregular rows. Mid tibia with two posteromedial setae.

Colouration: Body, including halter, dark brown in base colour. Notum with light bluish tint anteriorly (often absent) and more intense greenish shine posteriorly. Calypter margin and hairs white. Female anepisternum with greenish tint. Abdomen (excluding tergite 1) metallic green.

Genitalia: (Figs 325-328 ) Epandrium with small posterodistal spine. Surstylus 1/2-length of epandrium and with several rows of tubercle-like setae on inner surface. Hypandrium subtriangular with short apical process. Metepiphallus smooth ventrally and with short ridge on separate lateral sclerite. Proepiphallus narrow and weakly sclerotised. Basiphallus U-shaped and relatively long. Distiphallus separated from phallophorus by height of basiphallus; base of distiphallus extending slightly past base of closely held mesophallus; large, stout, and well-developed with especially long, broad, high distal section. Ejaculatory apodeme large and well-developed.

Hosts.

Asteraceae - Rudbeckia laciniata *.

Distribution.

KS*, MA*, MD*, NH*, NY*, PA*, VA.

Type material.

Holotype: USA. VA: Montgomeny Co., Blacksburg, 28.v.1962, J.G. Chillcott, CNC358457 (1♂, CNC).

Additional material examined.

USA. KS: Lawrence, J.M. Aldrich (1♂, USNM), MA: Boston, May, A.L. Melander (1♀, USNM), MD: Glen Echo, 28.v.1919, J.M. Aldrich (1♀, USNM), Plummers Isl., at light, 28.iv.1914, R.C. Shannon (1♀, USNM), Chain Bridge, 12.ix.1913, R.C. Shannon (1♀, USNM), Montgomery Co., Bethseda , 3.vi.1972 (5♂, USNM), 28.v.1986 (1♀, USNM), 3.vi.1986 (2♀, USNM), 6.ix.1981 (1♂, USNM), Howard Co. , Fulton , 21.v.1989, M.J. and R. Molineaux, J.E. Creeden (1♂, USNM), NC: Carteret, Co., Atlantic Beach , 3-4.ix.1984, G.F. and J.F. Hevel (1♀, USNM), NH: Franconia Ntch , 8.vii.1931, A.L. Melander (2♀, USNM), NY: Ithaca , 31.v.1914, A.L. Melander (1♂ 2♀, USNM), New York City , “vCortlndPk”, 15.v.1926, A.L. Melander (1♀, USNM), PA: Pittsburg , McCandless Township , Allegheny Co. , J. Plakidas, 20.ix.1978, "fly larva feed on gall tissue" (1♂, USNM), VA: Glencarlyn , 12.vi.1920, J.R. Malloch (1♂, USNM), Glencarlyn , 21.viii.1929, emg., “8-9.29”, Rudbeckia gall, J.C. Bridwell (1♂, USNM), nr. Plummers Isl. , 19.x.1914, R.C. Shannon (1♀, USNM), Montgomery Co. , Bethseda , 3.vi.1972, G. Steyskal (2♀, USNM), Talbot Co. , McDaniel (Wades Point), 19-21.ix.1986, Malaise trap, salt marsh with flowering Baccharis , W.E. Steiner (1♀, USNM), Northampton Co. , Kiptopeke , 4-6.x.1986, W.E. Steiner et al. (1♂ 1♀, USNM) .

Comments.

Melanagromyza virginiensis has widely separated ori, as in all other species of the M. virens group, and the fronto-orbital plate is only ¼ the width of the frons. The phallus is most diagnostic, with the distiphallus being especially long and stout-bodied with the distolateral margins nearly parallel and the ventrolateral tubules pronounced.

While the host species is not mentioned on any of the specimen labels, the male collected by Plakidas was reared from Rudbeckia laciniata ( Plakidas 1982). It is interesting that this Melanagromyza atypically induces a gall, as apparent from both Plakidas’ specimen and the reared specimen from Virginia.

Figures

Figures 52 - 63. Melanagromyza buccalis Spencer, head 52 anterior 53 lateral 54, 55 M. glyptos sp. nov., head 54 anterior 55 lateral 56, 57 M. virens (Loew), head 56 anterior 57 lateral 58, 59 M. virginiensis Spencer, head 58 anterior 59 lateral 60 Melanagromyza sp., female (S. A. Marshall - Cuba) 61 Melanagromyza sp., female (S. A. Marshall - Ontario, Hornings Mills) 62, 63 M. virens (Loew), lectotype, head 62 anterolateral 63 lateral.

Figures 325 - 328. Melanagromyza virginiensis Spencer, male genitalia 325 hypandrium, ventral 326 hypandrial complex, left lateral 327 phallus and epiphallus, ventral 328 external genitalia, ventral.