The soybean aphid feeds by piercing plant tissue and sucking out plant fluids.

Soybean aphid can cause reduction in growth and seed production. According to a study by Wang et al. (1996) in China, seed yields were reduced by 27.8% and plant height decreased by 20.2 cm in infested plants. In the United States, yield reductions can exceed 50% in severely infested fields.

The soybean aphid is a vector of a number of viral plant diseases, including abaca mosaic, soybean mosaic, soybean stunt, beet mosaic, millet red leaf, mungbean mosaic, bean yellow mosaic and Indonesian soybean dwarf.