Plant-mediated effects of growth-regulator herbicides (fluazifop-butyl, sethoxydim, and mefluidide) were observed in laboratory experiments using Mexican bean beetle (MBB),Epilachna varivestisMulsant, on soybean and lima bean plants. MBB larvae reared on sethoxydim-treated soybean plants took longer to pupate than did those on untreated plants, and pupal weights of MBB larvae reared on fluazifop-butyl-treated soybeans were reduced. Lima bean treated with fluazifop-butyl produced heavier MBB pupae than did untreated controls. MBB adults preferred untreated soybean plants in feeding tests over those treated with fluazifop-butyl or sethoxydim one day earlier, but 8–22 days later there was a preference for both hosts treated with these herbicides. Newly emerged MBB adult mating pairs caged on treated soybean plants produced greater numbers of eggs and egg masses per reproducing female than did beetles on untreated plants. These herbicides could have influenced the acceptability of the plants for feeding and their suitability for egg production and larval development by altering plant physiology.