Agromyza deserta (Patton)

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

Agromyza deserta (Patton)

Cecidomyiaceltis deserta Patton, 1897: 247. Spencer 1990: 54.

Agromyza deserta . von Tschirnhaus 2016: 153; Scheffer and Lonsdale 2018: 85.

Description

(von Tschirnhaus 2017: figs 6-9). Wing length 3.4 mm (♂). Female unknown. Length of ultimate section of vein M4 divided by penultimate section: 0.4. Eye height divided by gena height: 4.5. Ocellar triangle not much larger than tubercle. Orbital plate narrow, inner margin weakly defined. Epistoma present, margin straight, as long as width of first flagellomere. Ventral margin of gena relatively straight, shallow anteriorly and deep posteriorly. Scutum densely matt. Costa extending to M1. Tibiae without medial setae

Chaetotaxy: Ocellar and postvertical setae strong. Two ori (three ori on right side), decreasing in length anteriorly; two ors. Minute interfrontals anteromedially on frons. Four dorsocentral setae on left side, five on right, decreasing in length anteriorly. Acrostichal seta strong. Acrostichal setulae in six irregular rows. Two or three anepisternal setae, four or five katepisternals.

Colouration: Setae dark brown. Mostly dark brown. Face, parafacial, gena and postgena (to point above midpoint of eye) and mouthparts yellowish white with dark brown line along venter of gena; lunule and antenna pale yellow with arista brown; frons light yellow with brownish/orange tint, with ocellar triangle and posterolateral corner of frons dark brown, faded brownish region around ocellar triangle, with brownish stripe along orbital plate almost to base of posterior ori, becoming indistinct anteriorly. Apices of femora and bases of tibiae narrowly yellow. Halter white with stem faintly brownish anteriorly. Calypter margin and hairs brown.

Genitalia: (von Tschirnhaus 2017: figs 1-3, 5) Cercus large, bent on outer margin and straight on inner; inner-distal surface with numerous pointed tubercle-like setae. Surstylus fused to epandrium, indistinct, without tubercle-like setae. Hypandrium subtriangular; apex rounded with narrow, pointed apodeme that may be 2 × as long as wide; inner lobe with basal section narrowing to point of attachment to thicker, angled distal section bearing row of several sockets, one of which has a moderately long seta. Postgonite with minute setulae in irregular double row; shape presumably similar to that of A. aristata . Phallophorus narrow, width <1/3 length. Basiphallus dorsally fused to phallophorus on narrow dorsal/left lateral sclerite, which is apically truncated; right lateral sclerite much narrower, but as long as left sclerite. Paraphallus and hypophallus absent. Ejaculatory duct becoming broader along length of basiphallus, thick along mesophallus. Mesophallus a single band-like ventral sclerite partially fused to distiphallus; nearly as long as basiphallus, strongly curved to form a shallow semicircle. Distiphallus very shallow, band-like, and ventrally curved, obliquely angled. Ejaculatory apodeme unknown.

Host.

Cannabaceae - Celtis occidentalis ( von Tschirnhaus 2016).

Distribution.

USA: CT, NY, WV.

Type material.

Holotype: USA. CT: Orange, gall on twig of Celtis occidentalis , W.H. Patton. [1 gall, Lost]

Other material.

USA. WV: Morgan County ca. 6 mi NW Hedgesville, 39°37'N, 78°03'W, ex twig swelling gall Celtis occidentalis , coll. 6-v-1998, em. 15-iii-1999, R. J. Gagné (1♂, USNM). [not examined]

Comments.

The adult of this species was thoroughly described in von Tschirnhaus (2016), which also provided a discussion on related species, host usage, and treatment in the literature.