Numbers of instars, weight gains, relative growth rate, relative consumption rate, and efficiency of conversion of ingested and digested food were measured for the velvetbean caterpillar,Anticarsia gemmatalisHübner, while feeding on six legume species: hairy indigo, lespedeza, soybean, sesbania, white sweetclover, and cowpea. Sesbania was the most suitable host; lespedeza the most unsuitable. Supernumerary instars were observed for larvae fed cowpea and lespedeza. Two other legumes, crotalaria and sicklepod, did not support complete larval development.