The Mexican bean beetle tends to only feed on bean plants, but on those plants, it does not eat the beans alone. These beetles, which have a shape and spotted markings that resemble ladybugs, will feed on the leaves, flowers and bean pods of soybeans, cowpeas, lima beans and snap beans.

Though they may attack various parts of a bean plant, the Mexican bean beetle will typically focus mostly on the plant's leaves, feeding heavily and often leaving nothing behind but the leaf's skeleton. Plants that are hit particularly hard may not be able to sustain life after a Mexican bean beetle attack.