The Coccinellidae are generally considered useful insects, because many species feed on aphids or scale insects, which are pests in gardens, agricultural fields, orchards, and similar places. Within the colonies of such plant-eating pests, they will lay hundreds of eggs, and when these hatch, the larvae will commence feeding immediately.[8] However, some species do have unwelcome effects; among these, the most prominent are the subfamily Epilachninae, which are plant eaters. Usually, Epilachninae are only mild agricultural pests, eating the leaves of grain, potatoes, beans, and various other crops, but their numbers can increase explosively in years when their natural enemies, such as parasitoid wasps that attack their eggs, are few. In such situations, they can do major crop damage. They occur in practically all the major crop-producing regions of temperate and tropical countries.