Harvester

Notes:

There are two to three generations in Canada and the northern U.S. and from three to six generations in the southern U.S.. Eggs are laid singly on leaves or stems near colonies of the woolly aphid prey. Caterpillars are present from June in the North and from February through early November in Florida. Because the harvester caterpillar is carnivorous, development proceeds very rapidly, with the larval stage being completed in as little as eight days. Harvester larvae have only four larval instars. Most other butterflies have five (Layberry et al. 2002). First instar larvae may restrain their larger aphid prey with silk prior to attacking them (Hall, unpublished observations). Some harvester caterpillars cover themselves with the remains of woolly aphids they have eaten. The carcasses are tied on with silk, perhaps to protect the caterpillars from predacious ants (that tend and protect the aphids) and other natural enemies. Harvester caterpillars are less likely to conceal themselves when their woolly aphid prey is tended by Camponotus and Formica ants.