278 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1945 



damaged and the adults occasionally feed on the tender foliage. The 

 sharp mandibles on the tip of the snout are used to puncture or drill 

 through the unfolded corolla of the squares and the carpel walls of the 

 bolls for feeding and egg laying (pi. 2, figs. 1 and 2). The feeding 

 punctures are usually larger and deeper than those for oviposition, but 

 both produce sufficient injury to make the bracts "flare" or open up, 

 the square to turn yellow, and usually shed or fall from the plant, 

 resulting in the loss of a potential boll of cotton. Weevils prefer small 

 bolls with tender carpel walls, though bolls of upland cotton are not 

 safe from weevils until 20 to 30 days old and those of sea island cotton 

 are attacked until they mature and open. The pearly-white eggs are 

 placed deeply within the cavities in squares or bolls and are difficult 

 to find, but the egg punctures are sealed over with a gummy secretion 

 that enables a careful observer to distinguish them from feeding punc- 

 tures. The eggs hatch in 3 or 4 days into white, wrinkled grubs about 

 %r> inch in length. After feeding from 7 to 12 days, depending on the 

 temperature, the larvae pupate within the square or boll in which they 

 develop. The pupal stage lasts for 3 to 5 days, the adults cut their way 

 out, and are ready to lay eggs after feeding for 3 or 4 days. Thus 

 with an average life cycle of 20 to 30 days, a laying capacity of 100 to 

 300 eggs per female, and 3 to 7 generations per season, an enormous 

 population of weevils develops by fall. Small bolls are shed in the 

 same way as the squares, but large bolls remain on the plants. The 

 lock or carpel of the boll in which a larva feeds fails to develop prop- 

 erly, the lint is cut, stained brown, and is partially or completely 

 ruined. When several larvae develop within a boll, as often occurs 

 when food is scarce, the entire boll may be ruined (pi. 3, fig. 1). The 

 winter is passed in the adult stage, largely under weeds or woods trash 

 within or near the cotton fields, in haystacks, Spanish moss, or any 

 place that affords protection from the cold (pi. 3, fig. 2). However, 

 some adults overwinter within the pupal cells in old bolls, especially 

 in the drier areas of the Southwest. Weevils require a longer period 

 to develop in bolls than in squares, but the adults are more robust and 

 better adapted to survive the winter than those developing in squares. 

 The fact that cotton is the principal host plant of the boll weevil 

 simplifies control. Adults will feed occasionally on okra and other 

 plants of the same family as cotton (Malvacea), but the only records 

 of breeding in plants other than cotton are from althea {Hibiscus 

 syriacus) and the so-called Arizona wild cotton (Gossypium thur- 

 beri). A few weevils have been reared from the seed pods of 

 althea growing in weevil-infested cotton fields, but Thurberia is 

 readily infested. Althea is an ornamental shrub extensively grown 

 in the south and a potential host if boll-weevil eradication should 

 be undertaken by noncotton zones (Journ. Econ. Ent., vol. 27, No. 



