Elasmus albizziaeBurks is a parasitoid of the mimosa webworm,Homadaula anisocentraMeyrick. Honeylocust foliage samples containing first-generation mimosa webworm cocoons were collected in Ames, Iowa, by using a stratified random sampling plan during 1985, 1986, and 1987. Survey objectives were to determine the percentage of parasitized first-generation webworm prepupae and to assess the potential ofE. albizziaein an integrated pest management program. Conservative determinations of first-generation parasitism of mimosa webworm prepupae byE. albizziaewere 44,39, and 47% for 1985, 1986, and 1987, respectively. Precise effects of this parasitism on webworm populations have not been determined. Mortality levels imposed byE. albizziaeshould, however, be taken into account when management practices are considered. The parasitoids are exposed during host-seeking activity and would be vulnerable to broad-spectrum insecticides applied when first-generation webworm larvae were spinning cocoons on honeylocust foliage. When insecticidal treatment is warranted for management, it is recommended thatBacillus thuringiensisinsecticides be adopted as the treatment of choice over broad-spectrum insecticides to minimize damage to the parasitoid complex.