Cardiac-glycoside
Guides
Aphis nerii
oleander aphid, milkweed aphid, sweet pepper aphid, nerium aphid
Aphis nerii is a cosmopolitan aphid species in the family Aphididae, primarily associated with plants in the dogbane family (Apocynaceae), especially milkweeds (Asclepias) and oleander (Nerium oleander). The species exhibits complex reproductive strategies including parthenogenesis and viviparity, with winged and wingless female morphs. It is a significant pest of ornamental plants and a known vector of multiple plant viruses. The species has been introduced widely beyond its native range and is now found in tropical, Mediterranean, and temperate regions globally.
Cycnia
Cycnia is a genus of tiger moths in the family Erebidae, erected by Jacob Hübner in 1818. The genus contains several North American species, including the well-studied dogbane tiger moth (Cycnia tenera), which is known for its sophisticated anti-bat acoustic defenses. Species in this genus are typically associated with dogbane and milkweed plants, sequestering cardiac glycosides for chemical protection.
Empyreuma
spotted oleander caterpillar moth
Empyreuma is a genus of tiger moths in the family Erebidae, containing three species. The genus name derives from the Greek ἐμπύρευμα, meaning "a live coal covered with ashes." Adults exhibit striking aposematic coloration with orange and black patterns that mimic stinging wasps. Larvae feed exclusively on oleander (Nerium oleander), a toxic plant containing cardiac glycosides that the caterpillars sequester for their own defense. The genus is notable for its acoustic courtship behavior, with males producing sounds detected by female tympanic organs.
Empyreuma pugione
Spotted Oleander Caterpillar Moth, Spotted Oleander Moth
Empyreuma pugione, the spotted oleander caterpillar moth, is a day-flying tiger moth native to the Caribbean region that was introduced to Florida in 1978. The adult moth exhibits striking orange and black aposematic coloration and wasp-like appearance, while the larvae feed on oleander (Nerium oleander) and other Apocynaceae. Both life stages sequester cardiac glycosides from their host plants, making them unpalatable to predators. The species is considered less destructive than its congener Syntomeida epilais due to solitary feeding habits and lower population densities.
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.
Lygaeus
seed bugs, milkweed bugs
Lygaeus is a genus of seed bugs in the family Lygaeidae, containing over 60 described species. Members are characterized by aposematic coloration—typically combinations of red, black, gray, and white—that advertises chemical defenses. Several species, notably L. kalmii (small milkweed bug), sequester cardiac glycosides from host plants, rendering them unpalatable to predators. The genus exhibits diverse feeding strategies ranging from seed-feeding specialization to opportunistic scavenging.
Lygaeus kalmii
Small Milkweed Bug, Common Milkweed Bug
Lygaeus kalmii is a seed bug in the family Lygaeidae known for its bright orange-red and black aposematic coloration. Adults measure 10–12 mm and feed primarily on milkweed seeds and flower nectar, though they exhibit dietary flexibility including scavenging on dead insects and feeding on seeds of other plants such as composites. The species sequesters cardiac glycosides from milkweed, making it unpalatable to predators. Unlike the migratory large milkweed bug (Oncopeltus fasciatus), L. kalmii is non-migratory and overwinters as adults. Two subspecies are recognized: L. k. kalmii in western North America and L. k. angustomarginatus in the east, distinguished by differences in the white markings on the membranous portion of the forewings.
Syntomeida epilais
Polka-Dot Wasp Moth, Oleander Moth, Uncle Sam Moth
Syntomeida epilais, commonly known as the polka-dot wasp moth or oleander moth, is a day-flying moth native to the Caribbean that has become established in the southeastern United States. The species is notable for its striking aposematic coloration—iridescent blue wings with white polka-dots and a red-tipped abdomen—that mimics the appearance of stinging wasps. Both adults and larvae sequester cardiac glycosides from their host plants, making them toxic to predators. The species possesses the most elaborate acoustic communication system known in the family Erebidae, with females producing ultrasonic signals to attract mates and defend against bats.