What's eating my prairie milkweed?

Prairie Milkweed (Asclepias hirtella) is a tall, hairy-stemmed prairie native and a confirmed host for monarch butterflies. Oleander aphids are the main troublesome pest, forming yellow colonies. Milkweed bugs feed on seeds. Deer occasionally browse young plants. Skip insecticides completely — any spray risks killing monarch and other butterfly caterpillars present on foliage.

Dense yellow colonies on stems and flower clusters; honeydew attracts ants and sooty mold reduces photosynthesis Hand-crush or rinse off with water; allow natural predators (ladybird beetles, lacewing larvae) to build up; never spray insecticide on milkweed species

Hairy orange, black, and white caterpillars defoliate stems in late summer in gregarious groups; can strip a plant quickly Hand-pick caterpillar clusters if defoliation is severe; they are native and also a milkweed specialist — plants regrow; many gardeners tolerate them as part of the milkweed ecosystem

Bright orange-and-black adults and nymphs cluster on seed pods feeding on seeds; seeds may be destroyed before dispersal Hand-remove if seed set is important; otherwise leave as part of the native pollinator garden; plant vigour not significantly harmed