weevil, common name for certain beetles of the snout beetle family (Curculionidae), small, usually dull-colored, hard-bodied insects. The mouthparts of snout beetles are modified into down-curved snouts, or beaks, adapted for boring into plants; the jaws are at the end of the snout. The bent antennae usually project from the middle of the snout. The largest weevils are about 3 in. (7.6 cm) long, with the average length being about  1⁄4 in. (0.6 cm). The snout varies greatly in length among the different species; in the curculios, or nut weevils, it may be longer than the body. Different weevil species attack different parts of plants—fruits, seeds, leaves, stems, or roots. In most species the female lays her eggs inside the plant tissue, on which the growing larvae feed. The granary weevil and rice weevil are serious pests of stored cereal grains. The thousands of other destructive weevil species include the sweet-potato, vegetable, alfalfa, clover leaf, strawberry, and pine weevils, as well as the cotton boll weevil, the most serious weevil pest in the United States. The seed weevils, including the bean weevil, are not true weevils, but boring beetles of another family; they feed on leguminous crops, such as peas and beans. Weevils cause millions of dollars' worth of damage annually. The bark beetles, or engraver beetles, are related to the weevils. True weevils are classified in the phylum Arthropoda, class Insecta, order Coleoptera, family Curculionidae.

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