Agromyza aristata Malloch

(Fig. 65)

Material examined. OKLAHOMA: Payne Co., Mehan, 36.014339° N, 96.996744° W, 5.iv.2016, em. by 11.iv.2017, M.W. Palmer, ex Ulmus rubra, #CSE3448, CNC939912 (1♂); VERMONT: Chittenden Co., South Burlington, Winooski Gorge, 16.v.2015, em. 24.iii–6.iv.2016, C.S. Eiseman, ex Ulmus rubra, #CSE2264, CNC654497–654499 (3♀).

Hosts. Ulmaceae: Ulmus americana L. (Frick 1959), U. * rubra Muhl.

Leaf mine. (Fig. 65) Usually beginning near the leaf margin; initially green and linear, later widening into a brown, elongate blotch. Frass is indistinct in the narrow, green portion, but later present in blackish particles that often form two rows, becoming more randomly scattered toward the end. Concentric feeding lines are evident in the blotch.

Puparium. Yellowish-brown; formed outside the mine.

Distribution. USA: AR (leaf mines only), FL (leaf mines only; Frost 1924), IL, IN, IA, NY, OH, *OK, PA, VA, *VT; Canada: AB, ON. We have also seen leaf mines (including photographs submitted to www.BugGuide.net) from MA, MD, NJ, NC, TN, WI, and NB.

Comments. This species is univoltine, with larvae feeding in April and May; pupae overwinter.