Some nine species of these shiny, flattened leaf beetles in the genus Microrhopala are found in North America and most are apparently associated with various Asteraceae. The common species in the Sonoran Desert are shiny black and marked with red. They are quite small, barely 3 mm in length; this small size and the flattened profile are related to larval stage which is spent tunneling within a leaf between the tough, upper and lower epidermis.

At Mesquite Wash, Maricopa Co., Arizona on 01 Aug. 2009 I found this same species feeding in the midribs of new foliage on Cocklebur (Xanthium strumarium) and Camphor Weed (Heterotheca subaxillaris).

Leaf miners tend to occur on plants with thick, somewhat succulent leaves. Some Sonoran Desert plants are adapted to drought conditions by virtue of such thickened leaves that store water through drought periods. Monoxia is another leaf-mining beetle found in the Sonoran Desert.