Chalepus bicolor (Olivier)

(Figs. 8, 44, 132)

Reared specimens. MASSACHUSETTS: Franklin Co., Northfield, 276 Old Wendell Rd., 18.vii.2016 (adult in mine), em. 20.vii.2016, C.S. Eiseman, ex Dichanthelium clandestinum (1 adult, iNat 203379123) ; NORTH CAROLINA: Scotland Co., Laurinburg, St. Andrews University, 2.vi.2015, em. 18.vi.2015, T.S. Feldman, ex Dichanthelium, # CSE2229 (3 adults, ZFMK) ; OKLAHOMA: Payne Co., Mehan, 36.014339° N, - 96.996744° W, 16.vi.2017, em. 22.vi.2017, M.W. Palmer, ex Dichanthelium malacophyllum, # CSE4260 (1 adult, ZFMK) .

Photographed mines. MASSACHUSETTS: Hampshire Co., Northampton, 20.vi.2015, C.S. Eiseman, Dichanthelium latifolium (iNat 203113969) ; MINNESOTA: Wabasha Co., Weaver Dunes Preserve, 17.vii.2015, C.S. Eiseman, Dichanthelium scribnerianum (iNat 203115339) ; NORTH CAROLINA: Scotland Co., Laurinburg, St. Andrews University, 7.vi.2016, Dichanthelium scoparium (BG 1235807) ; OHIO: Hocking Co., South Bloomingville, Deep Woods Farm, 5.viii.2016, C.S. Eiseman, Dichanthelium clandestinum (iNat 203116048) ; OKLAHOMA: Payne Co., Mehan, 36.014339° N, - 96.996744° W, 30.v.2016, M.W. Palmer, Dichanthelium malacophyllum .

Hosts. Poaceae: Dichanthelium clandestinum (L.) Gould (Butte 1968a; Eiseman 2014), D. *latifolium (L.) Harvill, D. *malacophyllum (Nash) Gould, D. microcarpon (Muhl. ex Elliott) Mohlenbr. (Ford & Cavey 1985), D. *scoparium (Lam.) Gould, D. scribnerianum (Nash) J.R. Thomas. Butte’s (1968a) record of “ Panicum nitidum Lam. ” (= D. nitidum (Lam.) Mohlenbr.) is based on Chittenden’s (1902) record of P. macrocarpon (= D. scribnerianum) from Maryland, and Wilcox’s (1979) record of “ Panicum oligosanthes Schultes var. Scribnerianum ” apparently is as well. Our record of a photographed leaf mine on D. scoparium is supported by the report by Clark et al. (2004) of collecting adults from this host.

Biology. The leaf mines (Fig. 44) were described by Eiseman (2014, 2015). The egg is glued to the lower leaf surface, near the apex, and is capped by a secretion that dries to form a hollow, rounded structure that is covered with minute bumps (Fig. 8). All frass is expelled from the full-depth mine at intervals along the leaf margin. The single specimen reared by Eiseman (2014) pupated outside its mine, but the reared specimens cited above all pupated internally. The young larva photographed on 5 August in Ohio represents the latest date we have found an immature Chalepus bicolor .

Parasitoid. Conura albifrons (Walsh) ( Chalcididae) was reared from a mine of Chalepus bicolor on Dichanthelium malacophyllum (CSE4259, UFES).

Notes. It is unfortunate that we were unable to rear the larva found in Minnesota, as Chalepus bicolor is not known from this or any of the adjacent states (Staines 2015).

Interestingly, our DNA barcodes of Chalepus bicolor show more similarity to those of Odontota horni Smith, O. dorsalis, and O. scapularis (Olivier) than to C. walshii (Crotch) . Chalepus and Odontota together form a distinct cluster in the neighbor joining tree. The Oklahoma specimen of C. bicolor is the sole representative of BIN BOLD: ADP4491, differing by 2.4% from the two North Carolina specimens of C. bicolor that constitute BIN BOLD: ADP4224.