Members of the Curculionidae can be identified by their well-developed snout, and clubbed and elbowed antenna. Adult cotton boll weevils range from 3 to 8.5 mm long and are yellowish-brown in color. The snout is about half as long as their body. One of the most distinctive characteristics of the species is the double-toothed spur on the inner surface of each front leg. The eggs of cotton boll weevil are pearly white, elliptical, and approximately 0.85 mm long. Mature cotton boll weevil larvae are white, legless, and 13 mm long. Mouthparts and head of the larvae are brown.
Cotton boll weevils are considered the key pest of cotton in the eastern United States. They first appeared in the U.S. in Texas around 1894. Their geographic range includes Central America, Mexico, Cuba, and regions in the southeastern U.S. where cotton is cultivated.
Adult cotton boll weevils overwinter under leaf litter, in woods, in weeds, and along fencerows surrounding cotton fields. Adults emerge between February and July. Emerging adults feed primarily on the terminal shoots of cotton seedlings. Adults lay their eggs within the flower buds or young fruits (bolls) of cotton. Larvae feed inside the boll and eventually destroy the plant. First generation females can lay an average of 200 eggs and eggs usually hatch in two to four days, depending on the temperature.
Many entomologists have devoted their careers to studying the cotton boll weevil's biology and control. Natural enemies have been imported as biological controls, but have proved insufficient to control this pest. Insecticides remain the major defense against cotton boll weevils. In the United States, cotton pest control is responsible for about 40% of pesticides applied.
Maria Whitehead, Forbes Boyle, & Graham McElveen ENT 301; Fall 2001
