Eupithecia is a genus of thousands of moths found world-wide. However, the Eupithecia moth’s caterpillar form in Hawaii is the only carnivorous caterpillar in the world! These caterpillars can technically be labeled as insectivores as even though they are carnivorous, they only eat insects.
There are 20 different kinds of these carnivorous caterpillars on Hawaii’s islands. Each caterpillar will have certain colorations to match the plants they prefer to sit and wait on. They could be brown like a stick, green like a stem, or any other color in between. One species will even cut out a section on a fern and camouflage itself like a leaflet.
The carnivorous caterpillars are just under an inch long. Their back legs are designed to hold the caterpillar steady on leaves, trees, etc. The front legs are bunched up around the face and are used for grasping and holding prey in place while the caterpillar eats.
The carnivorous caterpillars have small hairs that sense prey similar to a Venus flytrap. Once an insect touches the hair, the caterpillar will spring forth and grab its prey. Holding the prey close to its mouth with its front legs, the carnivorous caterpillar will eat the insect. The video below from National Geographic show the caterpillar grabbing a fly!
Once the carnivorous caterpillars enter into their cocoon phase, they will reside in them for anywhere between a couple weeks to a couple months. Amazingly, once the carnivorous caterpillar turns into a Eupithecia moth, it’ll act like all of the other Eupithecia moths feeding only on plants.