This data release includes metadata and tabular data that documents species of caterpillars collected from different plant species at Hakalau Forest National Wildlife Refuge during 2017-2018. Data sets document (1) numbers of caterpillars collected on each plant species, (2) caterpillar host plant associations, (3) the fate of caterpillars during rearing, (4) types of mandibles possessed by different caterpillar species, and (5) a plant and caterpillar species list.