Phytomyza palmeri Eiseman & Lonsdale 2018, spec. nov.
Creators: name: Eiseman, Charles S.
name: Lonsdale, Owen
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Agromyzidae
Phytomyza
Phytomyza palmeri

description: Phytomyza palmeri spec. nov.
(Figs. 196, 343–347)
Holotype. OKLAHOMA: Payne Co., Mehan, 36.014339° N, 96.996744° W, 20.xi.2015, em. 30.xi.2015, M.W. Palmer, ex Symphoricarpos orbiculatus, #CSE2655, CNC634997 (1♂).
Paratypes. OKLAHOMA: same collection as holotype, CNC 634987–634998 (3♂ 7♀); 7.xi.2015, em. 17.xi.2015, M.W. Palmer, ex Symphoricarpos orbiculatus, #CSE2163, CNC 564616, CNC 564617 (2♀); 11.xii.2015, em. 18.xii.2015, M.W. Palmer, ex Symphoricarpos orbiculatus, #CSE2656, CNC 634770 (1♂).
Etymology. This species is named for Michael W. Palmer, botanist, who collected the type series as well as a number of other specimens used in this study.
Host. Caprifoliaceae: Symphoricarpos orbiculatus Moench.
Leaf mine. (Fig. 196) Upper surface, gradually widening, at least sometimes linear throughout, but often contorted to form a secondary blotch. The black frass is in closely spaced grains or beaded strips, allowing the larva’s path to be traced even when the mine forms a nearly continuous blotch.
Puparium. Brown; formed within the mine, its anterior spiracles projecting ventrally through the upper epidermis.
Distribution. USA: OK.
Adult description. Wing length 1.7–1.9mm (♂), 1.9–2.2mm (♀). Eye height divided by gena height: 5.6–6.1. First flagellomere rounded; covered with longer hairs (except at base). Orbital plate ill-defined. Notum pruinose. Vein dm-cu absent.
Chaetotaxy: Two ors, two ori (anterior ori 1/3–1/2 length). Ocellar seta subequal to ors, postvertical slightly longer. Cephalic setae thinner. Four dorsocentral setae decreasing in length anteriorly, second seta approximately 3/ 5 first seta, fourth barely larger than setulae; only first seta strong with others thinner.
Coloration: Setae dark brown, genal setae slightly paler. Head mostly yellow; scape and pedicel brownish to light brown, first flagellomere slightly darker brown to dark brown; orbital plate light yellow; posterolateral corner of frons dark brown to base of inner vertical; head below antenna light yellow with center and ventrolateral region of face deeper yellow, venter of gena with light brown line and clypeus brownish; ocellar spot slightly larger than tubercle, concave posteriorly, region between spot and back of head brownish. Thorax brown with grayish to brownish pruinosity that is slightly bluish or coppery on anterior half of notum; postpronotum dirty white with brown spot; notopleuron paler brown with yellowish mottling; pleuron paler brown, anepisternum yellowish dorsally and sometimes yellow mottled. Calypter white with hairs light brown. Haltere white. Legs mostly light brown to brown, paler than thorax; fore coxa yellow with base brown; yellow streaking dominant on fore femur, less prominent on mid femur; fore tibia and tarsi yellowish, mid tibia and tarsi slightly less so. Abdomen brown with epandrium paler.
Genitalia: (Figs. 343–347) Surstlyus small, rounded, fused to epandrium; epandrium with thin lobate process from posterior margin. Postgonite elongate, with narrow curved apex and single medial seta. Basiphallus divided into two dark band-like sclerites; basal arm on left sclerite wrapping around shaft; right sclerite dorsally fused to phallophorus and with rounded dorsal subbasal process. Hypophallus entirely membranous, with long anteromedial flagellum. Paraphallus absent. Mesophallus indistinct, incorporated into distiphallus as shallow basal stem. Distiphallus dark, flat, angled dorsally, medially divided past base into one pair of pointed lobes with paler distal annulations.
Comments. Three other Nearctic Phytomyza species are known to mine leaves of Symphoricarpos, all in the periclymeni superspecies. Their mines are discussed below under Phytomyza sp. 4. These and other Caprifoliaceaemining species are best treated in Griffiths (1974a) as part of the genus Chromatomyia, where examination of the male genitalia is almost always required for species diagnosis. The hypophallus is usually present in the Caprifoliaceae-mining Phytomyza, at least as a small vestigial sclerite (e.g. P. alpigenae Hendel), but it is absent in three known species— P. palmeri on Symphoricarpos and P. sempervirentis on Lonicera, both newly described here, and P. nigrilineata (Griffiths), also on Lonicera (a minute hypophallus sclerite is erroneously depicted in the original description).
Phytomyza palmeri can be differentiated from the above by a wing length of 1.7–1.9mm (♂) and 1.9– 2.2mm (♀), a narrower gena, a light yellow frons, a mostly white postpronotum, extensive yellow markings on the fore and mid femora, a short basiphallus and a distiphallus that is stouter and wider with distal annulations (Figs. 346, 347). Phytomyza sempervirentis is larger (wing length 2.1–2.2(♂) and 2.2–2.4mm (♀)), only the apex of the fore femur is yellow, and it has a higher gena, a brown frons, a brown postpronotum, a longer paler basiphallus and a more gracile distiphallus with one pair of lateromedial lobes (Figs. 356-359). Phytomyza nigrilineata is nearly identical to P. sempervirentis, but in the former there is yellowish mottling around the postpronotum, all femora are widely yellow apically (not just the fore femur), the distiphallus appears to have shorter, narrower distal arms with a darker accessory laterobasal process, and the single basal process of the distiphallus is stouter and as long as the distal section (based on the illustration in the original description, as the genitalia are now permanently embedded and only visible laterally).
The leaf mine most similar to that of Phytomyza palmeri is apparently that of P. caprifoliae Spencer, but based on Griffiths’ (1974a) description and illustration for that species, P. palmeri seems to have a more distinctly linear mine. It may not always be possible to distinguish the two should they prove to be sympatric.
description: Published as part of Eiseman, Charles S. & Lonsdale, Owen, 2018, New state and host records for Agromyzidae (Diptera) in the United States, with the description of thirty new species, pp. 1-156 in Zootaxa 4479 (1) on pages 78-79, DOI: 10.11646/zootaxa.4479.1.1, http://zenodo.org/record/1452913