Milkweed-specialist
Guides
Euchaetes antica
Euchaetes antica is a small moth in the family Erebidae, described by Francis Walker in 1856. It is distributed across the southwestern United States and Central America, ranging from Arizona and New Mexico south through Mexico to Nicaragua, Honduras, and Guatemala. The species exhibits sexual dimorphism in forewing length, with males measuring 13–15 mm and females 16–20 mm. Larvae feed specifically on Asclepias subverticillata, a milkweed species.
Euchaetes egle
Milkweed Tussock Moth, Milkweed Tiger Moth
Euchaetes egle is a tiger moth in the family Erebidae, commonly known as the milkweed tussock moth or milkweed tiger moth. The species is notable for its gregarious caterpillars that feed on milkweeds and dogbane, sequestering cardiac glycosides from their host plants for chemical defense. Adults produce ultrasonic clicks from tymbal organs to warn bats of their unpalatability, representing a rare case of acoustic aposematism. The species occurs across eastern North America with one generation annually in northern regions and two or more in southern areas.
Oncopeltus fasciatus
Large Milkweed Bug
The large milkweed bug is a medium-sized true bug distributed throughout North America from southern Canada to Costa Rica. It is a specialist feeder on milkweed seeds, sequestering cardiac glycosides from its host plant for chemical defense. The species undergoes annual long-distance migrations, wintering in southern states and Mexico before returning north in spring. Both nymphs and adults display striking orange and black aposematic coloration warning predators of their toxicity.
Rhyssomatus lineaticollis
Milkweed Stem Weevil
Rhyssomatus lineaticollis, commonly known as the milkweed stem weevil, is a specialized herbivore associated with milkweed plants (Asclepias spp.). Adults feed on stems and leaf petioles, while larvae develop inside seed pods. The species is notable for its monophagous to oligophagous relationship with milkweeds, including the common milkweed (Asclepias syriaca) and the rare, threatened Asclepias meadii. Research indicates this weevil is relatively sedentary, with limited dispersal distances, functioning as a patchy population in fragmented agricultural landscapes. The species is distributed across eastern and central North America.
Tetraopes tetrophthalmus
Red Milkweed Beetle
Tetraopes tetrophthalmus, commonly known as the red milkweed beetle, is a longhorn beetle (Cerambycidae) specialized on milkweed host plants. Both its genus and species names derive from Ancient Greek for "four eyes," referring to the extreme adaptation where antennal bases bisect the compound eyes. Adults are aposematically colored in red and black, warning predators of their toxicity derived from sequestered cardiac glycosides. The species exhibits specialized behaviors including vein-cutting to disable latex defenses, vibrational communication for mating and territorial contests, and substrate-borne signaling distinct for different social contexts.