ABSTRACT
The range caterpillar, Hemileuca oliviae Cockerell, is a major pest on rangeland grasses in New Mexico. Larvae consume grass which would otherwise be available for sheep and cattle. Abiotic factors can affect the abundance and distribution of range caterpillar on a broad scale. Water relationships for egg and early instars of the range caterpillar have been examined in several studies. One of the most interesting aspects of range caterpillar ecological relationships is its feeding preference. Plant productivity has been cited as one of the most important factors affecting range caterpillar density. The local habitat of the rangeland, as characterized by the dominant grass species present, can affect the abundance and distribution of the range caterpillar. The activities of mammals appear to influence strongly the distribution and abundance of range caterpillar. T. S. Bellows et al. gathered compelling evidence that predation by woodland rodents, especially the mouse Peromyscus truei, on range caterpillar eggs and pupae restricts the range caterpillar to grasslands.
