Agromyza rudbeckiana Scheffer & Lonsdale

(Figs. 76–77)

Material examined. IOWA: Winneshiek Co., 43°26'32.50"N, 92°0'10.32"W, 17.vii.2015, em. 13.viii.2015, C.S. Eiseman, ex Heliopsis helianthoides, #CSE1995, CNC564707, CNC564708 (2♂) ; MASSACHUSETTS: Franklin Co., Northfield, 276 Old Wendell Rd., 18.vii.2016, em. 5–7.viii.2016, C.S. Eiseman, ex Heliopsis helianthoides, #CSE2846, CNC654189–654193 (1♂ 4♀) ; OHIO: Delaware Co., Sunbury, Monkey Hollow Rd., 20.vii.2015, em. 7–17.viii.2015, C.S. Eiseman, ex Heliopsis helianthoides, #CSE1972, CNC564733–564745 (3♂ 9♀ 1 unemerged from puparium).

Hosts. Asteraceae: * Heliopsis helianthoides (L.) Sweet, Rudbeckia L. (Scheffer & Lonsdale 2018). The “undetermined yellow-flowered composite” illustrated by Scheffer & Lonsdale appears to be Heliopsis helianthoides .

Leaf mine. (Figs. 76–77) Greenish, turning brown; a blotch mine that may be compact or narrow and elongate, in the latter case following the leaf margin; frass diffuse. Scheffer & Lonsdale (2018) stated that the mine starts at the leaf apex, but this is not always the case. Up to four white larvae may feed in a single mine.

Puparium. Brown; formed outside the mine.

Distribution. USA: *IA, *MA, NY, *OH, VT (Scheffer & Lonsdale 2018).

Comments. Scheffer & Lonsdale (2018) collected larvae from Rudbeckia in June and adults emerged after overwintering. All of our specimens were collected as larvae in July and adults emerged within a month. Larvae from all three collection sites were observed to exit their original mines and establish new ones elsewhere (Fig. 77). The ability to do so is common in other leaf-mining flies ( Anthomyiidae, Drosophilidae, Ephydridae), but in five years of rearing we have observed it in Agromyzidae on just one other occasion. This was on Hackelia virginiana (L.) I.M. Johnst. ( Boraginaceae) in Dutchess Co., New York on 22 June 2013; unfortunately we were unable to rear adults. Phytomyza ovalis Griffiths is the only agromyzid recorded from Hackelia, but it is not known to occur east of Colorado. A group of Agromyza species is associated with Boraginaceae and the New York Hackelia feeder may be one of these.