Chalepus walshii sayi Butte

Eiseman, Charles S., Feldman, Tracy S. & Palmer, Michael W., 2024, New larval host records, parasitoid records, and DNA barcoding data for North American leaf-mining leaf beetles (Coleoptera: Chrysomeloidea), Zootaxa 5549 (1), pp. 1-60 : 16

Chalepus walshii sayi Butte

( Fig. 45 )

Barcoded specimen. COLORADO: Chaffee Co., Poncha Springs, South Arkansas River, 8.vii.2015,em. 12.vii.2015, C.S. Eiseman, ex × Triticosecale , # CSE3886 (1 larva, ZFMK) .

Hosts. * Poaceae : × Triticosecale Wittm. ex A. Camus. Adults have been collected on Bromus spp. , including B. anomalus Rupr. ex E. Fourn. ( Thomas & Werner 1981; Clark et al. 2004).

Biology. The single larva was found mining a leaf of a glaucous triticale (wheat–rye hybrid) that had been planted as part of a riverbank stabilization effort ( Fig. 45 ). There was associated adult feeding sign like that of Chalepus walshii walshii ( Eiseman 2014) . The egg covering was identical to that of C. w. walshii ( Eiseman 2015) and the egg was likewise attached near the tip, but it was on the lower rather than the upper leaf surface. More significantly, the frass was retained in the mine in scattered elongate pellets and short strips, whereas frass is absent (or nearly so) from mines of C. w. walshii ( Eiseman 2015) . The larva abandoned the mine four days after collection, and attempts at reintroducing it to the leaf were unsuccessful.

Notes. This is the first record of any hispine from wheat ( Triticum L.) or rye ( Secale L.) ( Staines 2015). Egg characteristics distinguish Chalepus from the other grass-mining hispines, Anisostena and Glyphuroplata , whose oviposition habits are discussed elsewhere in this paper. We consider it likely that this was a larva of C. w. sayi because no other Chalepus is recorded from Colorado, but it remains to be seen whether this western subspecies consistently differs in its retention of frass in the mine. The larva’s DNA barcode showed matches of 98.92% and 98.77% to those of our reared adults of C. w. walshii ; all of these specimens belong to BIN BOLD:ADO7382.

Figures

FIGURES 44–49. Leaf mines of Chalepus spp.; 44: C. bicolor on Dichanthelium clandestinum; 45: C. walshii sayi on × Triticosecale; 46: C. walshii walshii on Dactylis glomerata, with egg at far right; 47: C. walshii walshii on Elymus repens (transmitted light); 48: same (reflected light); 49: C. walshii walshii on Phalaris arundinacea.