Despite having a lot of their favorite host plant (swamp milkweed) in my backyard, I have only seen the milkweed leaf beetle (Labidomera clivicollis) a few times.
Milkweed leaf beetles are vegetarian — they prefer the leaves and flowers of just about any milkweed species. Their bold black and orange coloration warns predators to stay away from a potentially poisonous meal, but these beetles don’t sequester the toxic milkweed chemicals like the monarch caterpillars do.
This is the only species of milkweed leaf beetle found north of Mexico, and is apparently pretty rare throughout some of its range. Surprising, since its close relative, the Colorado Potato Beetle is a real pest. But one researcher found that the larvae of this beetle are highly vulnerable to predation when they occur on milkweed species growing in an old field or prairie where the vegetation is continuous. They survive much better on swamp milkweed where the plants might be surrounded by a moat of water, a barrier to the roaming predators. Well then, welcome to my garden.
The one beetle I found in the morning acquired a friend by the evening. I imagine it’s difficult to stay affixed to a large, spherically shaped, slick, waxy object when your legs are too short to get a good hold. The male continually tapped the female’s back with his antennae while trying to jockey himself into position.
“Slip-slidin’ away…You know the nearer your destination, the more you slip sliding away.” Paul Simon’s lyrics seem appropriate for this couple.