Phytomyza chelonei Spencer, 1969

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 chelonei Spencer

Figs 24 , 25 , 754-756

Phytomyza chelonei Spencer, 1969: 234. Spencer and Steyskal 1986b: 312.

Description.

Wing length 3.1-3.5 mm (♂), 3.6 mm (♀). Vein dm-m absent. Eye height divided by gena height: 2.4-3.6. Fronto-orbital plate slightly projecting. Parafacial narrow; cheek distinct, at least as high as ventral region of gena.

Chaetotaxy: Two ori; two ors. Four dorsocentrals, one presutural, decreasing in height anteriorly. Four to five sparse, scattered rows of acrostichal setulae that nearly reach posterior margin of scutum.

Colouration: Head mostly pale yellow; antenna light brown to brown with first flagellomere dark brown; ocellar triangle not distinct, but brown to dark brown spot slightly larger than tubercle, bulging anterolaterally to sometimes form a rounded square; posterolateral margin of frons brown, spot reaching base of inner vertical seta and extending slightly anteriorly, but not reaching base of fronto-orbitals; clypeus dark yellow to dark brown; palpus light to dark brown; back of head dark brown. Thorax dark brown with dense grey pruinosity that is strongest dorsally; remainder of body with faint pruinosity evident on pigmented regions; similar whitish pruinosity along lateral margin of frons (as seen in some Phytoliriomyza ). Halter white. Calypter entirely whitish yellow. Legs brown with bases of tibiae narrowly yellow and apices of femora yellow for length nearly equal to width of femur apex. Abdomen brown, sometimes with posterior margin of tergites yellow (holotype with most of first and second tergites yellow with wide brownish medial spot).

Genitalia: (Figs 754-756 ) Inner lobe of hypandrium with one seta and broadly membranous, with membrane spreading around inner margin of hypandrium. Postgonite long, broad and mostly flat with large outer lobe and folded inner layer. Basiphallus Y-shaped with short apical split and longer dorsomedial plate that is irregular to right side and better sclerotised along left. Paraphallus narrow, dark, and sinuate with small pigmented spot below base. Mesophallus shorter than paraphallus, clear, and laterally compressed, being only broader at rounded base (base tapered when viewed laterally). Distiphallus as high as mesophallus, appearing bifid ventrally but fused along length, and with narrow transverse pigmented band basally; “halves” of distiphallus straight, as in HT, or V-shaped, as figured. Ejaculatory apodeme short, barely widened apically, and with stout base; sperm pump without ventral sclerotisation.

Host.

Plantaginaceae - Chelone glabra .

Distribution.

Canada. QC. USA: IN, NC, TN.

Type material.

Holotype: Canada. QC: Old Chelsea, em. 18.vii.1965, ex. fruit of Chelone glabra , J.R. Vockeroth (1♂, CNC, type No. 10435).

Additional material examined.

Canada. QC: Old Chelsea , 18.vii.1965, J.R. Vockeroth, ex fruit Chelone glabra , CNC480075 (1 puparium [gel capsule], CNC) . USA. NC: Mt. Mitchell , 6800', 12.viii.1957, J.G. Chillcott (1♂, USNM), Mt. Mitchell , 2072 m, 12.viii.1957, J.G. Chillcott, CNC480076 (1♂, CNC), Highlands, 1158 m, 21.viii.1957, J.G. Chillcott, CNC480078 (1♀, CNC), TN: Great Smoky Mountains N.P., Indian Gap to Clingman’s Dome, 5200-6600', 6.viii.1957, J.G. Chillcott (1♂, USNM), Gr. Sm. Mt. Nat. Park, Indian Gap to Clingman’s Dome, 1584-2011 m, 6.viii.1957, J.G. Chillcott, CNC480077 (1♂, CNC) .

Comments.

The male terminalia of Phytomyza chelonei are similar to those of P. osmorhizae , in that the distiphallus is clear and membranous with a pigmented subapical band, but the terminalia are otherwise different, including the presence of a sclerotised hypophallus in the latter. Phytomyza osmorhizae is also smaller (wing length 2.1-2.4 mm) and darker with fewer than four fronto-orbitals.

Figures

Figures 24 - 36. Phytomyza chelonei Spencer, larva 24 lateral 25 same, anteroventral 26 - 28 Phytomyza misella Spencer, puparium 26 lateral 27 same, anterior 28 same, posterior 29 - 31 cephalopharyngeal skeleton, lateral 29 Agromyza anthracina Meigen 30 Liriomyza pusilla (Meigen) 31 Phytomyza horticola Goureau 32, 33 puparium, anterior end, dorsal 32 Phytomyza milii Kaltenbach 33 Tropicomyia theae (Cotes) 34 - 36 posterior spiracles 34 Agromyza albipennis Meigen 35 Melanagromyza lappae Loew 36 Phytomyza ranunculi (Schrank). Figs 29 - 36 reproduced from Dempewolf (2001).

Figures 754 - 759. Phytomyza chelonei Spencer, male genitalia 754 hypandrium and postgonite, ventral 755 hypandrial complex, left lateral 756 phallus, ventral 757 - 759 P. osmorhizae Spencer, male genitalia 757 hypandrial complex, left lateral 758 phallus, ventral 759 hypandrium and postgonite, ventral.