Phytomyza bicolor Coquillett, 1902

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

Phytomyza bicolor Coquillett

Figs 138 , 748-750

Phytomyza bicolor Coquillett, 1902: 191. Frick 1959: 426; Spencer and Steyskal 1986b: 203.

Description

(Fig. 138 ). Wing length 3.2-3.5 mm (♂), 3.4-3.8 (♀). Vein dm-m absent. Eye height divided by gena height: 2.1-2.8. Eye relatively small and round; parafacial and fronto-orbital plate produced dorsally, visible laterally. Labellum relatively long and pointed. With faint brown pruinosity that is denser dorsally on head and thorax.

Chaetotaxy: Two to four ori; two ors (anterior seta inset). Ocellar and postocellar setae exceeding length of ors. Four dorsocentrals, one presutural, decreasing in height anteriorly. Up to six scattered rows of acrostichal setulae, strongly reduced in number posterior to second dorsocentral.

Colouration: Head light brown to yellowish with palpus brown, ocellar tubercle, posterior margin of frons, lateral margin of frons (stripe barely touching base of fronto-orbitals, disappearing anteriorly), clypeus, venter of gena, face, first flagellomere, lunule (at least widely above antennal bases) and back of head dark brown; gena and frons sometimes browner. Thorax dark brown with postpronotum and notopleuron sometimes reddish. Calypter white with hairs dark brown. Halter white. Legs dark brown. Female abdomen yellow with oviscape dark brown and anterior margin of tergite 6 (and sometimes 4 and 5) brownish; male abdomen as described for female except tergite six, sternite 8 and epandrium brownish; sometimes abdomen brown past tergite 3 or anterior 1/2 of tergite 3 brown and tergites 1 and 2 brownish, but posterior margins of tergites 2-5 always yellow.

Genitalia: (Figs 748-750 ) Inner lobe of hypandrium with separate, elongate medial process. Postgonite well-developed. Basiphallus halves narrow, flat, dorsal, left sclerite longer and fused to phallophorus. Hypophallus membranous. Paraphalli dark, narrow, converging to base of distiphallus; wider and paler basally. Mesophallus short, pigmented, slightly wider than duct, widening to distiphallus. Distiphallus made up of one pair of dark, very narrow tubules that diverge basally and are nearly parallel on distal 1/2. Ejaculatory apodeme very small with distal 1/2 of blade pale to clear; sperm pump with small, sclerotised patch.

Host.

Unknown - adult ON female photographed on Caltha palustris ( Ranunculaceae ).

Distribution.

Canada. ON*. USA. CT*, IN, NY, TN*, VA.

Type material.

Holotype: USA. NY: Niagra Falls, 23.vi (1♀, USNM, type No. 6663).

Additional material examined.

Canada. ON: Spring Creek , 10.vi.2007 [1♀, photo voucher by S.A. Marshall] . USA. CT: Stanford , 18.v.1919, A.H. Sturtevant (2♂ 1♀, USNM), NY: Ithaca, 3.vi.1917, S.H. Emerson (1♂, USNM), Ithaca, 11.vi.1935, H.K. Townes (1♀, USNM), Remus Pt., Chautauqua Lake , 31.v.1963, swampy woods, W.W. Wirth (2♂, USNM), Allegany State Park , 28.v-3.v.1963, stream margin, W.W. Wirth (1♀, USNM), TN: Sevier Co., Rte. 441, 3mi NW NC/TN border, Great Smokey Mtn. N.P., 35°38.3'N, 83°27.8'W, 4500', 27.v.1999, S.D. Gaimari (1♀, USNM), VA: Shenandoah , Big Meadows , 15.vi.1941, A.L. Melander (3♂, USNM), Fairfax Co. , Turkey Run Park , nr. Mouth of Turkey Run , 38°57.9'N, 7°09.4'W, Malaise trap, 18-30.v.2007, D.R. Smith (1♀, USNM), Smyth Co. , Mt. Rodgers, 1432-1615 m, 1.v.1962, J.R. Vockeroth, CNC480074 (1♀, CNC) .

Comments.

The pale abdominal tergites of Phytomyza bicolor are highly diagnostic, making this species easy to identify externally. The photo voucher included here (Fig. 138 ) is the first record of this species in Canada.

Figures

Figures 131 - 138. 131 Phytomyza (Napomyza) lateralis Fallen, female and puparium 132 Phytomyza compta (Spencer), male holotype, lateral 133 Phytomyza nervosa Loew, lateral, with detail of proclinate orbital setulae (arrow) 134 Phytomyza crassiseta Zetterstedt, female (D. Cheung - Ontario) 135 Phytomyza sp., female (S. A. Marshall - Hornings Mills) 136 Phytomyza sp., female (B. Dupree - Georgia, Atlanta) 137 Phytomyza sp., female (K. Hall - Washington, Lacey) 138 Phytomyza bicolor Coquillett, female on Caltha palustris (S. A. Marshall - Ontario, Spring Creek).

Figures 748 - 750. Phytomyza bicolor Coquillett, male genitalia 748 hypandrial complex, left lateral 749 phallus, ventral 750 hypandrium and postgonite, ventral.