Meat-Eating Caterpillars: less than 1% of all known lepidoptera (moths and butterflies) are carnivorous, and even fewer are known to hunt and kill their prey; these are just a few of the exceptions
Above: a carnivorous pug moth caterpillar, Eupithecia orichloris, ambushing a fly
Lepidopteran predators are extremely rare, but they do exist. Some of the most interesting examples include the carnivorous pug moth caterpillars of the genus Eupithecia, the ant-eating casebearer, the Hawaiian snail-eating moth, and the bone-collector caterpillars of the genus Hyposmocoma. Curiously, almost all of the species on this list are endemic to Hawaii.
Above: Eupithecia orichloris
The carnivorous pug moth, Eupithecia orichloris, is probably the most famous predatory caterpillar in the world, thanks to the alarming manner in which it captures its prey -- this species is an ambush predator that disguises itself as a twig, waits for a hapless bug to wander by, and then pops up out of nowhere, violently plucking its prey from the foliage.
Eupithecia is the only lepidopteran genus that is known to contain ambush predators, which makes this behavior seem even more bizarre.
Above: the ant-eating casebearer and its unique "shell"
The ant-eating casebearer, Ippa conspersa, is another carnivorous caterpillar that feeds on ants and other insects, both as a predator and as a scavenger. This species uses silk, sand, and other fine debris to build a flat, peanut-shaped "shell" around its body, and that "shell" serves as a kind of camouflage, allowing the caterpillar to sneak into ant nests and hunt.
Above: an ant-eating casebearer feeding on a cockroach
As its name implies, the ant-eating casebearer often feeds on ants, but it has also been known to eat cockroaches and other small arthropods.
Above: this photo shows a Hawaiian snail-eating moth using strands of silk to hold its prey in place
Hyposmocoma molluscivora, commonly known as the Hawaiian snail-eating moth, is a casebearing caterpillar that feeds on live snails. It uses strands of silk to immobilize its prey, tethering the snail in place so that it can climb into the victim's shell and feed on the soft flesh within. The caterpillars of this genus are the only lepidopterans that are known to feed on molluscs; all of the other predatory caterpillars feed on arthropods (insects and arachnids).
The genus Hyposmocoma also contains the predatory "bone-collector" caterpillars, which cover themselves with the body parts of other insects and arachnids, often scavenging the leftover pieces from spiderwebs. They carefully trim each piece of exoskeleton and then arrange them all together onto a portable silk mesh.
Above: a bone-collector caterpillar covered in the body parts of other insects, including a large weevil head that is clearly visible near the center, several ant heads, a fly's leg, the abdomen of a bark beetle, a wing, and several pieces of antennae, among other things
Bone-collector caterpillars often live side-by-side with spiders, as they opportunistically feed on the insects that they find trapped in spiderwebs; their macabre body ornaments likely serve as camouflage, allowing the caterpillars to avoid being detected or attacked by local spiders.
Other carnivorous moths have been featured in at least two of my previous posts, including a post about the "vampire moths" of genus Calyptra, which have been known to drink human blood, and a post about planthopper parasite moths, which are technically more parasitoid than predatory.
Sources & More Info:
Journal of the Lepidopterists' Society: Predatory and Parasitic Lepidoptera
GeoJournal: Behavior, Biogeography, and Conservation of Eupithecia in the Hawaiian Islands
Korean Journal of Applied Entomology: The First Record of the Myrmecophilous Tineid Moths of Genus Ippa in Korea
Nature: Caterpillars Eat Snails Out of House and Home
Science: Web-Spinning Caterpillar Stalks Snails
NBC: Hawaiian Caterpillars Hunt like Spiders
National Geographic: This Camouflaged Critter Wears Severed Insect Body Parts like a Coat
Scientific American: Carnivorous "Bone Collector" Caterpillars Wear Corpses as Camouflage
Science: Hawaiian Caterpillar Patrols Spiderwebs Camouflaged in Insect Prey's Body Parts
