Mimallonidae is a family of over 300 named species in 43 genera, known as “sack-bearer” moths for the larval case-building behavior.
These moths are found only in the New World, and are distributed in North America, Central America, South America, and the Caribbean (Cuba and The Bahamas). The vast majority of genera and species are found in the neotropics, with only five described species from the United States.
Not much has been published on the natural history of adult Mimallonidae, though most species are thought to be nocturnal. At least three species have diurnal males. Young caterpillars live inside folded leaves or beneath silken networks, and build portable or semi-portable cases out of silk, frass, and plant material as they grow. The cases are open on either end and vary from irregular in structure to spindle-shaped. The openings of the cases can be blocked by the head and/or the flattened anal plate of the last segment of the body. The sack-like case-making behavior of the caterpillars have earned them the common name “sack-bearers”.
Mimallonidae larvae feed on several families of plants, including (but not limited to): Anacardiacaea, Clusiacaea, Combretacaeae, Fagaceae, Melastomaceae, Myrtaceae and Rubiaceae.