Ophiomyia euthamiae 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
Ophiomyia
Ophiomyia euthamiae

description: Ophiomyia euthamiae spec. nov.
(Figs. 8–9, 87–88, 240–244)
Holotype. MASSACHUSETTS: Franklin Co., Northfield, 276 Old Wendell Rd., 29.x.2015, em. 23–24.iii.2016, C.S. Eiseman, ex Euthamia graminifolia, mines mostly on underside of leaf, but puparium on upper surface, #CSE2263, CNC634791 (1♂).
Paratypes. MASSACHUSETTS: Franklin Co., Northfield, 276 Old Wendell Rd., 7.x.2015, em. 27–29.iii.2016, C.S. Eiseman, ex Euthamia graminifolia, mines on both sides of leaf, #CSE2284, CNC654079, CNC654080 (1♂ 1♀); 10.x.2015, em. 27.iii–12.iv.2016, C.S. Eiseman, ex Euthamia graminifolia, mines on both sides of leaf, #CSE2285, CNC654173–654188 (7♂ 9♀); same collection as holotype, CNC634788–634790, CNC634792 (4♀). Tentatively identified material. MASSACHUSETTS: Franklin Co., Northfield, 276 Old Wendell Rd., 7.x.2015, em. 29–31.iii.2016, C.S. Eiseman, ex Euthamia graminifolia, mines on underside of leaf, #CSE2289, CNC654197, CNC654198 (1♂ 1♀).
Etymology. The specific epithet refers to the host plant, Euthamia Nutt. ex Cass. (Asteraceae).
Host. Asteraceae: Euthamia graminifolia (L.) Nutt.
Leaf mine. (Figs. 87–88) Whitish; very long and narrow, mostly on the lower surface (Fig. 88), but ending on the upper surface (Fig. 87); frass black, mostly in widely spaced grains.
Puparium. (Figs. 9, 87) Black; formed within the mine.
Distribution. USA: MA, VT.
Adult description. Wing length 2.0– 2.2mm (♂), 2.1–2.4mm (♀). Length of ultimate section of vein CuA1 divided by penultimate section: 0.7–0.8. Eye height divided by gena height: 5.8–9.6. First flagellomere small, rounded. Arista pubescent. Ocellar triangle longer than wide, nearly attaining level of posterior ori; tubercle shallow. Eye obliquely slanted. Lunule wide, very shallow. Facial carina high, bulb prominent but not wider than carina dorsal to it, which is broadly and shallowly grooved. Genal process approximately as long as high, with sides forming slightly less than a 60° angle. Clypeus with sides bowed posteriorly, very narrow and subrectangular anteriorly, apex sharply truncated with minute points at corners. Notum with faint grayish pruinosity.
Chaetotaxy: Two ors, two ori; one or two ori usually slightly more gracile and/or strongly incurved. Ocellar and postvertical setae subequal to ors. Male fasciculus with several upcurved setae. Two strong dorsocentral setae. Eight rows of acrostichal setulae. Mid tibia with one small posterolateral seta sometimes present (present in holotype).
Coloration: (Fig. 8) Setae black. Body dark brown with greenish metallic shine sometimes faintly evident on notum and abdomen of male; female thorax greenish or coppery, abdomen usually more distinctly coppery. Calypter margin pale, hairs dark brown. Haltere brown.
Genitalia: (Figs. 240–244) Epandrium shallow, curved anteriorly to point of fusion with surstylus. Surstylus small, rounded with two irregular rows of tubercle-like setae on inner surface. Hypandrium stout and relatively broadly rounded with slight apical process. Phallophorus dark, constricted basally and with dorsum shorter. Basiphallus with relatively broad, irregular right lateral arm slightly exceeding level of mesophallus base; basally connected to much shortened left arm. Mesophallus tubular, base level with that of distiphallus, inserted ventromedially into distiphallus. Distiphallus in ventral view rounded laterally, widest before midpoint, base tapered and broadly rounded, apex longer and more gradually tapering, with strong ventromedial suture and tuberculate sides; relatively flat in lateral view; basal 1/3 closed dorsally by weak textured membrane that ends before emergence of slight medial shelf; with shallow, ill-defined dorsomedial process, pigmented apically. Ejaculatory apodeme with stout base and short stem with narrow sclerotized tuberculate process to one side and short membranous tube to the other; blade rounded and asymmetrical with pale margin and strong medial rib; sperm pump with strong transverse sclerotized band with rounded, domelike ends.
Comments. Ophiomyia euthamiae spec. nov. is externally indistinguishable from most other congeners with a fasciculus and genal process of approximately 60°, making the genitalia essential for examination during diagnosis, especially when differentiating O. maura, which also occurs on Euthamia. The mesophallus is approximately level with the distiphallus basally or slightly longer; the distiphallus is very shallow (being not much thicker than the mesophallus), the membranous lobe ventral to the distiphallus is large (shallow in O. maura), the anterodorsal process is weakly defined, the medial shelf-like process is straight and short (longer and curved in O. maura), the dorsobasal pouch of the distiphallus is internally minutely spinulose dorsally (smooth in O. maura), and in ventral view, the distiphallus is spindle-shaped, with a wide, rounded middle, tapered base, and narrow apex (thicker and more gradually tapered in O. maura) (Figs. 243, 244).
On the same host plant, we have found mines that are similar but remain on the lower leaf surface throughout their length; these are entirely invisible from above. The puparia are whitish in the examples we photographed, but were black in the only specimens we reared (#CSE2289). In these specimens the distiphallus is slightly thinner and the left distolateral membrane arising from the margin of the distiphallus is sclerotized slightly further. Whether these represent the same species requires further investigation. One entirely lower surface mine was found with a bluish puparium; this yielded an adult of O. maura.
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 20-21, DOI: 10.11646/zootaxa.4479.1.1, http://zenodo.org/record/1452913