boll weevil or cotton boll weevil (bōl), cotton-eating weevil 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
..... Click the link for more information. , or snout beetle, Anthonomus grandis. Probably of Mexican or Central American origin, it appeared in Texas about 1892 and spread to most cotton-growing regions of the United States. Over the years the weevil became a significant pest, destroying about 8% of the annual U.S. cotton crop. Boll weevil devastation was a major reason for diversification of the South's historic cotton economy. In 1978, however, the U.S. Dept. of Agriculture began a concerted eradication campaign. By the end of the century the weevil had disappeared from from most of the nation except Texas, Louisiana, and Mississippi, where the campaign continued.

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 insect, invertebrate animal of the class Insecta of the phylum Arthropoda . Like other arthropods, an insect has a hard outer covering, or exoskeleton, a segmented body, and jointed legs. Adult insects typically have wings and are the only flying invertebrates.
..... Click the link for more information. ) 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 Integrated Pest Management (IPM), planned program that coordinates economically and environmentally acceptable methods of pest control with the judicious and minimal use of toxic pesticides.
..... Click the link for more information. , 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 Arthropoda (ärthrŏp`ədə) [Gr.,=jointed feet], largest and most diverse animal phylum.
..... Click the link for more information. , class Insecta, order Coleoptera, family Curculionidae.

Bibliography

See P. P. Sikorowski et al., Boll Weevil Mass Rearing Technology (1984); G. Matthews and J. Tunstall, Insect Pests of Cotton (1992).

boll weevil

Boll weevil (Anthonomus grandis)

(credit: Harry Rogers)

Small beetle (Anthonomus grandis) found almost everywhere cotton is cultivated. It is the most serious cotton pest in North America. Adults vary in size according to how much food they received as larvae, but they average about 0.25 in. (6 mm) long, including the long, curved snout. In the spring adults deposit eggs in cotton buds or fruit. After hatching, the larvae live within the cotton boll, destroying the seeds and surrounding fibres. Because the larvae and pupae remain inside the cotton bolls, they cannot be killed with insecticides. The boll weevil destroys an estimated three to five million bales of cotton annually.