Moths and butterflies are by far the most vegetarian of all the major insect orders; probably less than 1% are carnivorous, some in a regular basis, others only when vegetable material is scarce or when they are crowded. I became interested in the problem when I was raising some sawfly larvae and they began to disappear; the culprit was another larva which I had missed at first. It soon became bigger than all the other larvae and the differences became obvious. It turned out to be Lithophane antennata, the Ashen Pinion
. Sam Jaffe and Dave Wagner identified the caterpillar and added some comments, see them under this image:
The most complete information on carnivorous caterpillars is provided by Naomi Pierce, the author of Predatory and Parasitic Lepidoptera: Carnivores living on plants
. (Journal of Lepidopterists’ Society. 49(4), 1995, 412-453).
According to Naomi Pierce’s paper there are predatory and parasitic Lepidoptera in the following superfamilies: Tineoidea, Gelechioidea, Tortricoidea, Zyganenoidea, Pyraloidea, Geometroidea, Noctuoidea and Papilionoidea.
Some species are only carnivorous under conditions of food scarcity or crowding; in such circumstances some may also resort to cannibalism. That is the case of the pinions. There are other species which are obligate carnivores, such as the planthopper parasite moth and the harvester.
The most spectacular carnivorous caterpillars are a few Geometridae of Hawaii that have evolved amazing predatory skills. Who would have thought that cute inchworms could be so ferocious? You can see them in action in this video
. More information in Geojournal
Some predatory and parasitic Lepidoptera present in Bugguide
A member of Papilionoidea: Feniseca tarquinius
The notorious planthopper parasite moth, the only member of the family Epipyropidae: Fulgoraecia exigua
Pyralids that feeds on scale insects, genus Laetilia
Three species of Cosmopterigidae are internal parasites of scale insects
(no images), Euclemensia bassettella
and Euclemensia schwarziella
A bagworm, family Psychidae, mostly herbivore; also feeds on mites and scale insects of the host plant
Pinion moths, members of the Noctuidae family, that ordinarily feed on plants but can resort to sawfly larvae and caterpillars, including some of their own siblings: Lithophane
A clothes moth that eats animal products along with wool: Tineola bisselliella
- Webbing Clothes Moth
Two crambids in the genus Chalcoela
- Sooty-winged Chalcoela
- Pegasus Chalcoela
The following are known to resort to cannibalism
under certain circumstances:
Several Noctuids: Helicoverpa zea
- Corn Earworm Moth (ref
- Fall Armyworm Moth
A few tiger moths, family Erebidae: Estigmene acrea
- Salt Marsh Moth
Pyrrharctia isabella (Isia)
- Isabella Tiger Moth
- Rattlebox Moth
In Hawaii, there is a species that feeds on snails, Hyposmocoma molluscivora
, according to Daniel Rubinoff, William P. Haines. Web-Spinning Caterpillar Stalks Snails. Science, 2005. It uses its silk to bundle the snail.
There may be others that I will be happy to add later.