 The species is distasteful and there is evidence that it emits aposematic ultrasound signals; these may also jam bat echolocation, as the functions are not mutually exclusive.It is a common feeder on "Apocynum cannabinum" (dogbane, Indian hemp) which produces a milky latex containing cardenolides, toxic cardiac glycoside that defend against herbivores.It also feeds on milkweed species, "Asclepias", at least in parts of its range, but is most commonly reported from dogbane.