Liriomyza orilliensis Spencer

(Fig. 78)

Material examined. IOWA: Winneshiek Co., Decorah, Twin Springs Park, 24.viii.2017, em.?, J. van der Linden, ex Prenanthes alba, # CSE4644, CNC1144028 (1♀) .

Photographed mines. MASSACHUSETTS: Franklin Co., Northfield, 276 Old Wendell Rd., 7.x.2015, C.S. Eiseman, Nabalus altissimus [aborted/predated mines]; Nantucket Co., Squam Swamp, 8.ix.2019, C.S. Eiseman, Nabalus trifoliolatus; MICHIGAN: Ingham Co., Okemos, Ted Black Woods, 19.vi.2019, C.S. Eiseman, Nabalus; NORTH CAROLINA: Guilford Co., Browns Summit, Haw River State Park, 29.v.2015, T.S. Feldman, Prenanthes alba [vacated mine], BG 1075103; VERMONT: Chittenden Co., Williston, Mud Pond, 28.viii.2016, C.S. Eiseman, Nabalus [vacated mines].

Hosts. Asteraceae: Nabalus * albus (L.) Hook., [ N. altissimus (L.) Hook., N. trifoliolatus Cass.], Taraxacum F.H.Wigg. (Eiseman & Lonsdale 2018) .

Leaf mine. (Fig. 78) Pale greenish to whitish, turning brownish; in some cases beginning as an irregular track, gradually expanding to an elongate blotch, with frass mostly in squiggly strips; in others, forming a more or less compact blotch with distinct secondary feeding lines, and with frass mostly in fine grains. Two or three larvae may feed together.

Puparium. Yellow to brown; formed outside the mine.

Phenology and voltinism. Data from the few known specimens of this species indicate it is at least bivoltine. Larvae collected in Massachusetts in mid-June emerged as adults in early July (Eiseman & Lonsdale 2018); a larva collected in Alberta in early August emerged as an adult the following spring (Lonsdale 2017a); and the Iowa specimen emerged on an unknown date from a larva collected in late August.

Distribution. USA: *IA, MA, [MI, NC, VT]; Canada: AB, ON (Eiseman & Lonsdale 2018).