Our Caterpillar of the Week, Ashen Pinion (Lithophane antennata) has attracted lots of attention for its diet, which includes other caterpillars.
We’ve really appreciated our fans’ openness to learning about a caterpillar that can attack and eat other caterpillars. We’ve also loved your engagement this week—your reactions have been so diverse, and your comments thought provoking. One response we keep seeing is something to the effect of, “WHOA! Caterpillars eat THAT?!”
When most of us think of caterpillars’ feeding habits, we picture a whole lot of leaf eating. But, as many of you know, some caterpillars eat other plant parts, such as flower petals, stems, fruits, roots, pollen, and seeds. Some eat plants you might not imagine caterpillars would consume, like ferns and mosses. Their host plants don’t have to be alive in all cases—some caterpillar species eat dead leaves.
Other caterpillars can eat non-plant organisms. Some dine on fungus. Some eat lichen. Sloth moth caterpillars feed on sloth dung!
And, as many of you have witnessed for yourselves this week, some caterpillars eat FLESH. There’s a broad range of caterpillars that exhibit this behavior.
Certain species indulge in same-species cannibalism, often in captivity or when food is in desperately short supply. The beloved Monarch caterpillar falls into this occasional-cannibal category, and has been observed eating the eggs, larvae, and chrysalids of its fellow monarchs.
Other species consume a variety of caterpillars—not just their own species—and they may prefer eating other caterpillars over leaves whenever they have an opportunity. Our caterpillar of the week and several of its Lithophane relatives fit into this group of opportunists. Cannibals and opportunists, scientists hypothesize, may use their flesh-feeding strategies as adaptations that help the fittest individuals survive when their host plants run low on edible material.
Still other caterpillars are obligate carnivores, meaning that they ONLY consume flesh. Here in New England, one such caterpillar is the Harvester, which only consumes wooly aphid species. Globally, there are plenty of caterpillar species that consume the likes of scale insects, leafhoppers, cicadas, ants and their brood, spider eggs, and dead insect remains.
We tend to think of caterpillars solely as herbivores—which is true for many species. But for others, there’s a lot more to eat than just plants!
--Liz Kautz, TCL Education Director