aphid (redirected from Plant lice)

aphid

an insect of the order Hemiptera. They parasitize many plants during the warm seasons. Of interest in animal health are the black aphids, Aphis craccivora, which can exist in very large numbers on burr trefoil, Medicago polymorpha, and may stimulate the production of phytoallexins in the plant which then photosensitize animals grazing the infested pasture.