Chalepus bicolor (Olivier, 1792)

Eiseman, Charles S., 2015, Notes on Leaf-Mining Chrysomelidae (Coleoptera) in New England, The Coleopterists Bulletin 69 (3), pp. 453-458 : 453

Chalepus bicolor (Olivier, 1792)

My previous account of this species did not mention the egg because it was absent from the mine from which I reared an adult. This was possibly a secondary mine, made by a larva that had wandered from its original leaf. The two other mines I examined had an egg attached to the lower surface near the tip of the leaf ( Fig. 1 ). The egg is oval, about 1.3 mm by 0.9 mm, and covered with a transparent secretion that glues it to the lower leaf surface. This in turn is capped by a hollow, rounded structure that is covered with minute bumps. This structure is broken into two or more pieces once the egg is hatched (and I have not observed unhatched eggs), but it is a secreted covering for the egg rather than a broken eggshell. The larva mines directly into the leaf without damaging the exposed surface of the egg, so it is unclear how the covering comes to be hollow and broken.

Adults feed on the upper surface of leaves of Dichanthelium clandestinum (L.) ( Poaceae ) in August, producing whitish patches similar to those made by Chalepus walshii (Crotch) on other grasses ( Eiseman 2014) but more irregular in outline.

Figures

Figs. 1–8. 1) Egg of Chalepus bicolor, lateral view); 2) Egg of Chalepus walshii, dorsal view; 3) Larva and leaf mine of Microrhopala xerene; 4) Abandoned mine of M. xerene, with pupal blister torn open; 5) Mine of Sumitrosis inaequalis in Symphyotrichum cordifolium; 6) Mine of Dibolia chelones, showing two frass types; 7) Mature larva of D. chelones; 8) Five young larvae of D. chelones in a single leaf.