page_title: Boll weevil
section_title: Lifecycle
hierarchical_section_title: Boll weevil / Lifecycle
caption_attribution_description: English: Title: Bulletin Identifier: bulletin4951190405unit (find matches) Year: 1904 (1900s) Authors: United States. Bureau of Entomology Subjects: Insects; Insect pests; Entomology; Insects; Insect pests; Entomology Publisher: Washington&#160;: G. P. O. Contributing Library: Smithsonian Libraries Digitizing Sponsor: Biodiversity Heritage Library View Book Page: Book Viewer About This Book: Catalog Entry View All Images: All Images From Book Click here to view book online to see this illustration in context in a browseable online version of this book. Text Appearing Before Image: Bui. 5 1, Bureau of Entomology, U. S. Dept. of Agriculture. Plate I. Text Appearing After Image: Stages of Mexican Cotton Boll Weevil. Fig 1 Cotton boll weevil, back view of adult; fig. 2, .side view of adult; fig. 3, egg; fig. 4, side view of larva; fig. 5, ventral view of pupa; lig. 6, adult, with wings spread—all except fig. 3 enlarged to four diameters; fig. 3 enlarged to twelve diameters (original). Note About Images Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.
context_page_description: The boll weevil is a beetle that feeds on cotton buds and flowers. Thought to be native to Central Mexico, it migrated into the United States from Mexico in the late 19th century and had infested all U.S. cotton-growing areas by the 1920s, devastating the industry and the people working in the American South. During the late 20th century, it became a serious pest in South America as well. Since 1978, the Boll Weevil Eradication Program in the U.S. allowed full-scale cultivation to resume in many regions.
context_section_description: Adult weevils overwinter in well-drained areas in or near cotton fields, and farms after diapause. They emerge and enter cotton fields from early spring through midsummer, with peak emergence in late spring, and feed on immature cotton bolls.
  The boll weevil lays its eggs inside buds and ripening bolls (fruits) of the cotton plants. The female can lay up to 200 eggs over a 10- to 12-day period. The oviposition leaves wounds on the exterior of the flower bud. The eggs hatch in 3 to 5 days within the cotton squares (larger buds before flowering), feed for 8 to 10 days, and finally pupate. The pupal stage lasts another 5 to 7 days. The lifecycle from egg to adult spans about three weeks during the summer. Under optimal conditions, 8 to 10 generations per season may occur.
  Boll weevils begin to die at temperatures at or below −5 °C (23 °F). Research at the University of Missouri indicates they cannot survive more than an hour at −15 °C (5 °F). The insulation offered by leaf litter, crop residues, and snow may enable the beetle to survive when air temperatures drop to these levels.
  Other limitations on boll weevil populations include extreme heat and drought. Its natural predators include fire ants, insects, spiders, birds, and a parasitic wasp, Catolaccus grandis. The insects sometimes emerge from diapause before cotton buds are available.
caption: 1) Back view of adult; 2) side view of adult; 3) egg; 4) side view of larva; 5) ventral view of pupa; 6) adult, with wings spread
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