Cardiac-glycoside-sequestration
Guides
Danaus
tiger milkweed butterflies, tigers, milkweeds, monarchs, wanderers, queens
Danaus is a genus of butterflies in the tiger butterfly tribe (Danaini), commonly known as tiger milkweed butterflies, monarchs, wanderers, and queens. The genus includes some of the most recognizable butterflies worldwide, notably the migratory monarch butterfly (Danaus plexippus). Species in this genus are characterized by their association with milkweed host plants (Asclepias spp.), from which larvae sequester cardiac glycosides for chemical defense. The genus has a global distribution spanning North America, South America, Africa, Asia, Indonesia, and Australia, and serves as an important model system for studying migration, plant-insect coevolution, and genome evolution.
Euchaetes
tussock moths, milkweed tussock moths, milkweed tiger moths
Euchaetes is a genus of arctiine tussock moths in the family Erebidae, described by Thaddeus William Harris in 1841. The genus includes species commonly known as milkweed tussock moths or milkweed tiger moths, many of which are specialized feeders on milkweed plants (Asclepiadaceae). Caterpillars of well-known species such as E. egle sequester cardiac glycosides from their host plants, making them unpalatable to predators. Adults of some species have evolved ultrasonic acoustic defenses against bat predation, representing a notable example of acoustic aposematism.
Oncopeltus
large milkweed bugs
Oncopeltus is a genus of seed bugs in the family Lygaeidae containing at least 40 described species. The genus is best known for the large milkweed bug (Oncopeltus fasciatus), a widely studied species that feeds on milkweed seeds and exhibits striking aposematic orange and black coloration. Members of this genus are specialized feeders on plants in the family Apocynaceae, particularly milkweeds (Asclepias), and have evolved the ability to sequester toxic cardiac glycosides from their host plants for defense. Several species undergo annual migrations between northern breeding grounds and southern overwintering 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.
Oncopeltus sanguineolentus
Blood-colored Milkweed Bug
Oncopeltus sanguineolentus, the blood-colored milkweed bug, is a seed bug in the family Lygaeidae found in Central and North America. The species belongs to the same genus as the well-studied large milkweed bug (Oncopeltus fasciatus), but has received less scientific attention. Like congeners, it is associated with milkweed plants and exhibits aposematic coloration warning predators of chemical defenses.
Saucrobotys futilalis
dogbane saucrobotys moth, dogbane webworm
Saucrobotys futilalis, commonly known as the dogbane saucrobotys moth or dogbane webworm, is a crambid moth native to North America. The species is notable for its specialized relationship with dogbane (Apocynum) and milkweed (Asclepias) plants, which serve as exclusive larval hosts. Larvae construct silken nests on host plants and exhibit a striking ontogenetic color change from cryptic green to aposematic orange with black spots as they mature. Both larval and adult stages sequester cardiac glycosides from their host plants for chemical defense against predators. The species has been recorded across a broad geographic range from northeastern North America to British Columbia and south to Texas and California.
Tetraopes
Milkweed Longhorn Beetles
Tetraopes is a genus of specialized longhorn beetles (Cerambycidae: Lamiinae) distributed from Guatemala to Canada. The genus is defined by extreme host specificity to milkweeds (Asclepias and related genera in Apocynaceae), with larvae feeding on roots and adults feeding on leaves and flowers. All species exhibit aposematic red-and-black coloration advertising their sequestration of cardiac glycosides from host plants. The eyes are completely divided by antennal insertions, giving rise to both the scientific name ("four eyes") and common name "four-eyed milkweed beetle" for some species. The genus represents a classic example of coevolutionary radiation with its host plants.
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.