Milkweed butterflies

Definition

A subfamily of brush-footed butterflies (Danainae, family Nymphalidae) whose larvae feed primarily on milkweeds (Asclepias and related genera of Apocynaceae), sequestering cardiac glycosides that render both larvae and adults chemically defended and often aposematically colored. The group includes the milkweed butterflies proper (Danaini), the clearwing butterflies (Ithomiini), and the Australasian Tellervini. Their specialized host-plant relationship and resulting chemical protection make them a classic example of coevolution and Müllerian mimicry complexes.

Etymology

From the association of their larvae with milkweed host plants (Asclepias spp.), which contain toxic cardenolides sequestered for defense.

Example

The monarch butterfly (Danaus plexippus), a classic milkweed butterfly, sequesters cardenolides from its Asclepias host plants, making larvae and adults unpalatable to vertebrate predators; its bright orange-and-black wing pattern advertises this toxicity to potential predators.

Synonyms

• Danaids
• Danainae

Related Terms

• Danainae
• Nymphalidae
• Brush-footed butterflies
• Monarch butterfly
• cardenolide sequestration
• aposematic coloration
• Müllerian mimicry
• Batesian mimicry
• Asclepias
• host-plant specialization
• Ithomiini
• clearwing butterflies

Usage Notes

While 'milkweed butterflies' often refers specifically to the tribe Danaini in casual usage, the broader subfamily Danainae includes additional tribes (Ithomiini, Tellervini) whose larvae may feed on other Apocynaceae or Solanaceae rather than true milkweeds. Specialists typically use 'Danainae' or 'danaids' for precision. The term emphasizes the ecological syndrome of milkweed herbivory and chemical defense rather than a strict phylogenetic grouping of host-plant specialists. Contrast with 'brush-footed butterflies' (the entire family Nymphalidae) and 'fritillaries' or 'admirals' (other nymphalid subfamilies with different host-plant relationships).