Cerodontha (Poemyza) incisa (Meigen)

(Figs. 28, 131)

Material examined. IOWA: Howard Co., Hayden Prairie State Preserve, 15.vii.2015, em. 30.vii.2015, C.S. Eiseman, ex? Phalaris, #CSE1910, CNC564724 (1♀). MASSACHUSETTS: Franklin Co., Northfield, 263 Capt. Beers Plain Rd., 11.vii.2012, em. by 27.vii.2012, C.S. Eiseman, ex Phalaris arundinacea, #CSE4, CNC358500 (1♀); 276 Old Wendell Rd., 2.viii.2014, em. 11.viii.2014, C.S. Eiseman, ex Phleum pratense, #CSE1302, CNC384827–384829 (1♂ 2♀); Plymouth Co., West Bridgewater, 41.991852, -71.033550, 7.viii.2013, em. 17.viii.2013, C.S. Eiseman, ex Cinna arundinacea, #CSE816, CNC392642 (1♀); Bridgewater, 16.viii.2013, em. 18–29.viii.2013, C.S. Eiseman, ex Cinna arundinacea, #CSE826, CNC384722–384724 (2♂ 1♀); Worcester Co., Phillipston, along Burnshirt River (42.52149046, -72.09219652), 4.vii.2017, em. 15.vii.2017, C.S. Eiseman, ex Calamagrostis canadensis, #CSE3955, CNC939733 (1♂); NEW YORK: Columbia Co., Ghent, 17.vii.2015, em. 3.viii.2015, C. Vispo, ex Phalaris arundinacea, #CSE2172, CNC654350 (1♂); NORTH CAROLINA: Durham Co., Durham, 28.v.2015., em. by. 3.vi.2015, T.S. Feldman, ex Poaceae, #CSE1585, CNC564649 (1♂); Pelham Road, 27.vii.2017, em. summer 2017, T.S. Feldman, ex Poaceae, #CSE4346, CNC939824–939825 (2♀); OKLAHOMA: Payne Co., Mehan, 36.014339° N, -96.996744° W, 2.vi.2017, em. 21.vi.2017, M.W. Palmer, ex Elymus canadensis, #CSE3935, CNC939907 (1♀).

Tentatively identified material. MASSACHUSETTS: Nantucket Co., Nantucket, Squam Swamp, 27.vii.2017, em. by 22.viii.2017, C.S. Eiseman, ex Juncus tenuis, #CSE4157, CNC 939650 (1♀).

Hosts. Poaceae: Agrostis “ alba L.” [= stolonifera L.?], Bromus tectorum L., Calamagrostis * canadensis (Michx.) P. Beauv., * Cinna arundinacea L., Elymus * canadensis L., E. glaucus Buckley, E. repens (L.) Gould, Hordeum vulgare L., Pascopyrum smithii (Rydb.) Á. Löve, Phalaris arundinacea L., Phleum pratense L., Setaria pumila (Poir.) Roem. & Schult., Triticum aestivum L., Zea mays L., Zizania aquatica L. (Frick 1959; Spencer 1969). Since Juncus tenuis Willd. (Juncaceae) would represent a new host family for Cerodontha incisa, we have chosen not to list it among the confirmed hosts until males can be reared from this plant.

Leaf mine. (Fig. 131) A whitish, sometimes inflated, upper surface blotch, with up to four larvae feeding together. Frass is in scattered black grains.

Puparium. (Fig. 28) Elongate, black, iridescent; formed within the mine.

Distribution. Widespread in the northern half of the US and in Canada, south at least to OK and NC; Europe; Pakistan; Japan (Nowakowski, 1973).