THE 



SWEETPOTATO WEEVIL 



How to control it 



The sweetpotato weevil,^ a serious 

 pest of sweetpotatoes, infests parts 

 of seven southern States — South 

 Carohna, Georgia, Florida, Ala- 

 bama, Mississippi, Louisiana, and 

 Texas. 



Sweetpotato growers can prevent 

 or reduce weevil damage by fol- 

 lowing recommended cultural and 

 cleanup practices and by using 

 insecticides. 



States combat the weevil on a 

 larger scale by maintaining quaran- 

 tines to prevent spread of the weevil 

 to uninfested areas and by carrying 

 out area-wide control programs. 

 The U. S. Department of Agriculture 

 cooperates with States in both types 

 of control effort. 



DEVELOPMENT 



The weevil can live and multiply 

 in sweetpotato fields, in stored 

 sweetpotatoes, and in certain fleshy- 

 rooted morning-glories that grow 

 wild along the South Atlantic and 

 Gulf coasts. 



It has four stages in its develop- 

 ment — egg, larva (grub), pupa 

 (resting stage), and adult. 



^ Cylas formicarius elegantulus. 



A generation is produced in 1 

 month to 6 weeks in warm weather. 

 In cool weather the weevil develops 

 more slowly. Generations succeed 

 one another as long as the weevil has 

 food. In areas along the South At- 

 lantic and Gulf coasts 6 to 8 gen- 

 erations may be produced in 1 year. 



Egg 



The female adult lays eggs in small 

 shallow holes that she punctures in 

 mature parts of the sweetpotato vine, 

 in the plant stem near the earth, in 

 the roots if she can reach them, or 

 in stored sweetpotatoes. 



Eggs are white and so small they 

 cannot be easily seen. They hatch 

 into larvae in about 1 week in warm 

 weather. 



Larva 



The larva grows to about three- 

 eighths inch long. It is white at first, 

 later becomes cream colored. Its 

 head is pale brown. 



As the larva feeds it burrows into 

 the stem or root, making a tunnel 

 that becomes larger as the larva 

 grows. 



In 2 or 3 weeks (or longer at cool 

 temperatures) the larva transforms 

 into a pupa. 



