Japagromyza viridula (Coquillett)

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

Japagromyza viridula (Coquillett)

Figs 49-51 , 251-256

Agromyza viridula Coquillett, 1902: 189. Frick 1952a: 374, 1959: 359.

Japanagromyza viridula . Spencer, 1966a: 3, 1969: 63; Spencer and Steyskal 1986b: 55; Scheffer et al. 2007: 770; Eiseman and Lonsdale 2018: 16.

Description

(Figs 49-51 ). Wing length 2.7-3.2 mm (♂), 3.1-3.2 mm (♀). Length of ultimate section of vein M4 divided by penultimate section: 0.6-0.7. Eye height divided by gena height: 8.0-8.3. Ocellar triangle faintly outlined. Fronto-orbital plate and ocellar tubercle subshiny. Lunule height 1/2 width, silvery pruinose; lunule and face broad and well-sclerotised with face flat. Clypeus broadly rounded. Notum and head with light dusting of pruinosity. Arista virtually bare.

Chaetotaxy: All setae well-developed and setulae short and sparse. Two ori; two ors (widely separated). Two postsutural dorsocentrals. Ten rows of acrostichal setulae; acrostichal setula present. Postocellar and ocellar setae well-developed. Fore tibia with one lateral seta; mid tibia with two posteromedial setae.

Colouration: Setae black (setulae on ocellar tubercle sometimes golden-brown). Body predominantly dark brown; thorax (less so on pleuron) and abdomen with metallic green reflection, and epandrium faintly to distinctly reddish brown. Wing veins brown. Calypter and halter white.

Genitalia: (Figs 251-256 ) Surstylus fused to epandrium; suture obliterated; very narrow, apex rounded, nearly as high as epandrium; inner surface with patches of numerous tubercle-like setae distally and basally; twisted, inner face visible posteriorly. Hypandrium large, elongate with very long, stout, apical process; inner lobe bare, narrow and transverse. Postgonite broad, ovate, flat, and bare. Phallophorus small, fused to basiphallus. Basiphallus a single plate dorsal to right lateral. Hypophallus slightly shorter than basiphallus, dark, linear. Distiphallus very long, pale, and relatively straight, composed of longer flagellum on left side and shorter flagellum on right side, connected by thin membrane; often longer than illustrated. Mesophallus indistinct. Ejaculatory apodeme narrow, blade reduced with very shallow basolateral process; sperm pump unsclerotised with minutely spinulose ventral surface.

Hosts.

Fagaceae - Quercus spp., Castanea mollissima ( Eiseman and Lonsdale 2018).

Distribution.

Canada: NB*, NS, ON, QC*. USA: DC, GA, IN, KS, MA, ME, NC, OK, PA, SC, TN, VA. Puerto Rico.

Type material.

Holotype: USA. DC: “June”, "Collection Coquillett" (1♂, USNM; Type No. 6660).

Paratypes examined.

USA. DC: “DC” (1♀, USNM), MA: Beverly, 29.vi.1876, Burgess (1♀, USNM). Puerto Rico. "Porto Rico", Aguadilla, i.1899, A. Busck (1♀, USNM).

Additional material examined.

142♂ 97♀ 1?, CNC, USNM. Canada. NB: Kouchibouguac N.P., 8.vi.1977, J.R. Vockeroth, Code - 5222V, Code - 52336, CNC358580, CNC358581, CNC358582 (3♀, CNC), 9.vii.1977, J.F. McAlpine, Code - 6023Q, CNC358583 (1♀, CNC), QC: Rigaud, 11.vi.1981, J.R. Vockeroth, CNC358579 (1♂, CNC) .

Comments.

Superficially, Japanagromyza viridula can be mistaken for species of Melanagromyza because of its metallic green colouration, but it can be easily separated by the single pair of stout prescutellar acrostichal setae.

There was an error produced in the Japanagromyza key in Spencer and Stegmaier (1973) that was perpetuated in Spencer and Steyskal (1986b) and Wiegmann (1991), leaving the only Delmarva species unidentifiable. Japanagromyza viridula was differentiated from U.S. congeners with prescutellar acrostichal setae ( J. inaequalis (Malloch), J. aequalis Spencer and J. polygonivora Wiegmann (= J. polygoni Spencer) by having the "mesonotum predominantly black". Upon examination of the types of all of these species deposited in the USNM, however, there appears to be little, if any difference in the colour of the notum. Instead, J. viridula can be diagnosed by the arista, which is virtually bare (hairs not as long or longer than width of central filament) by examination of the male genitalia, or sometimes by the setulae on the ocellar tubercle, which are black or golden-brown (always black in the remaining species, which are only found in and south of Florida).

Figures

Figures 45 - 51. Euhexomyza albicula Spencer, male paratype 45 lateral 46 head, anterior 47, 48 Euhexomyza winnemannae (Malloch), female holotype 47 head, anterior 48 lateral 49 - 51 Japanagromyza viridula (Coquillett) 49 head, anterior 50 same, lateral 51 dorsal (T. Murray - Massachusetts, Plymouth).

Figures 251 - 256. Japanagromyza viridula (Coquillett), male genitalia 251 external genitalia, posterior 252 external genitalia, anterior 253 external genitalia, left lateral 254 hypandrium and postgonite, ventral 255 hypandrial complex, left lateral 256 phallus, ventral.