Members of the genus Paranthrene are borers in horizontal roots and under bark of trees.
The abdomen is mostly yellow, with the head an orange or rust color. The thorax is brownish black, and the forewing is opaque, orange or rust colored. Wingspan is 11-18 mm. The female is similar to the male.
There are two other color forms described. The first, "perlucida," features an abdomen and thorax that are a deep red color. In the second form, "palescens," the entire moth is pale yellow.
Paranthrene robiniae can be found from the Rocky Mountains to the California coast, to Alaska and the desert Southwest.
The preferred hosts are poplars (Populus) and willows (Salix). Paranthrene robiniae are attracted to weakened or damaged trees of both species, and attack stems and branches. The species can also be destructive to ornamental plantings of birches (Betula).
Related or Similar Species
Paranthrene robiniae, Paranthrene dollii, and Paranthrene tabaniformis form a closely related group that tends to exploit the same resources.