The young adult is grayish, darkening with age, and about 1/4 in. (6 mm) long, with a long snout for boring into the cotton boll, or seed pod, where weevils feed on the cotton fibers. Weevils may also invade cotton flower buds before they mature into bolls. Females lay eggs within the bud or the boll, where pupation (see insect) occurs. The larvae eat the entire contents of the boll. Metamorphosis from egg to adult takes about three weeks; from 2 to 10 generations occur each season. The weevil's resistance to some poisons, and the removal of some poisons from the market, have encouraged Integrated Pest Management, e.g., the use of safer insecticides, synthetic growth regulators, and pheromone traps, and the release of sterile males to frustrate reproduction. Adults are also controlled by elimination of field litter, especially cotton stalks, in which they overwinter. Short-season cotton, bred to mature early, escapes much damage from weevil larvae.
The boll weevil is classified in the phylum Arthropoda, class Insecta, order Coleoptera, family Curculionidae.
See P. P. Sikorowski et al., Boll Weevil Mass Rearing Technology (1984); G. Matthews and J. Tunstall, Insect Pests of Cotton (1992).
Any of about 40,000 beetle species in the largest family of beetles, Curculionidae, which is also the largest family in the animal kingdom. Most weevils have long, elbowed antennae that may fold into special grooves on the prominent snout. Many species are wingless. Most species are less than 0.25 in. (6 mm) long, are plainly coloured and marked, and feed exclusively on plants. Some species are more than 3 in. (80 mm) long. The larvae may feed on only a certain part of a plant or a single plant species; adults are less specialized. The family includes many destructive pests, including the boll weevil.
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Boll weevil (Anthonomus grandis)
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