Nemorimyza maculosa (Malloch)

(Figs. 165–166)

Material examined. FLORIDA: Palm Beach Co., Boynton Beach, 2.i.2016, em. 4.i.2016, T.S. Feldman, ex Emilia, #CSE2227, CNC654342–654345 (2♂ 1♀ 1 puparium) ; MASSACHUSETTS: Nantucket Co., Nantucket, Little Sesachacha Pond, 2.ix.2012, em. 3.x.2012, J . A. Blyth, ex Erechtites hieracifolia, #CSE109, CNC480523, CNC480524 (2♂) ; Nantucket Co., Nantucket, N. Liberty St., 41°17′4.02″N 70°6′19.59″W, 7.viii.2012, em. 23.viii.2012, C.S. Eiseman, ex Erigeron canadensis, #CSE43, CNC480555, CNC480556 (1♂ 1♀) ; Worcester Co., Sturbridge, 42°2′28.84″N, 72°5′32.47″W, 5.vii.2016, em. 23–24.vii.2016, C.S. Eiseman, ex Erechtites hieraciifolia, #CSE2797, CNC654276–654289 (7♂ 6♀ 1 ex) ; NORTH CAROLINA: Scotland Co., Laurinburg, St. Andrews University, 2.vi.2015, em. 15–16.vi.2015, T.S. Feldman, ex Erechtites hieraciifolia, #CSE1622, CNC653950–653953 (3♀ 1 puparium) ; OHIO: Hocking Co., South Bloomingville, Deep Woods Farm, 6.viii.2016, em. 24.viii.2016, C.S. Eiseman, ex Erigeron canadensis, #CSE2935, CNC654477 (1♂) ; same collection data, em. 26–29.viii.2016, ex Erechtites hieraciifolia, #CSE2953, CNC638902 (1♀); OKLAHOMA: Payne Co., Mehan, 36°0′51.62″N, 96°59′48.28″W, 30.v.2016, em. 23.vi.2016, M.W. Palmer, Grindelia squarrosa, #CSE2615, CNC634780, CNC634781 (2♀) .

Hosts. Asteraceae: Arctium lappa L., Artemisia vulgaris L., Aster spp. (cultivated varieties), Baccharis douglasii DC., B. halimifolia L., Bidens alba (L.) DC., B. pilosa L., Chromolaena odorata (L.) R.M. King & H. Rob., Chrysanthemum spp. (cultivated varieties), Dendranthema indicum (L.) Des Moulins, Emilia coccinea (Sims) G. Don, Erechtites hieraciifolius (L.) Raf. ex DC., Erigeron canadensis L., Gaillardia aristata Pursh, Gamochaeta pensylvanica (Willd.) Cabrera (as Gnaphalium “ spathalium ” Lam.), * Grindelia squarrosa (Pursh) Dunal, Helianthus annuus L., Lactuca sativa L., Melanthera aspera (Jacq.) Steud. ex Small, Mikania micrantha Kunth, Packera glabella (Poir.) C. Jeffrey, Sonchus asper (L.) Hill, Tagetes erecta L., T. patula L. (leaf mines only) (Frick 1959; Stegmaier 1967d; Diaz et al. 2015). Spencer & Steyskal (1986) also listed Calendula officinalis L. and Solidago, but the origin of these records is unclear.

Leaf mine. (Figs. 165–166) A dirty brown blotch (greenish on Grindelia), often containing several larvae. The margins of the mines on Emilia were partially clean and whitish. Spencer & Steyskal (1986) state that the mines may be confused with those of Nemorimyza posticata, but according to Ellis (2016) N. maculosa mines lack the feeding lines that are conspicuous in N. posticata mines, and this is mostly consistent with our observations, except for some irregular feeding lines visible in a backlit photo of an Erigeron mine. The mines we examined were mostly formed at the tips of the leaves and no initial narrow portion was evident. Also, N. posticata larvae are always solitary in our experience and we have seen nothing in the literature to suggest otherwise.

Puparium. Brown, formed outside the mine.

Distribution. Present in all southern states, north to WI and MA; common in CA; HI; Canada: ON (Spencer 1981); Caribbean; Central and South America (Martinez & Etienne 2002).