128 INSECTS OF ECONOMIC IMPORTANCE 



cycle about four weeks on the average ; several ^gen- 

 erations during- a season ; passes winter as adults in 

 tropical regions south of the United States; mi- 

 grates northward in spring. 



Control — Dusting cotton with powdered arse- 

 nate of lead best method; this insect is now held to 

 be of value in controlling the boll weevil and there- 

 fore is not foueht as it used to be. 



Cotton bollworm -^ (HcliofJiis obsoleta) 

 Order — Lepidoptera 



One of the serious pests of cotton; moth deposits 

 ribbed eggs on leaves of cotton; larva feeds for a 

 short time on leaves but soon bores into a boll where 

 it destroys the lint; life cycle about 30 days in sum- 

 mer; four generations a season; passes winter as 

 pupa 3 to 6 inches below the surface of the soil ; also 

 attacks corn and tomatoes. 



Control — Use trap crops of corn; plough land 

 thoroughly during fall and winter ; plant crop early 

 in spring; rotate and diversify crops. 



The pink cotton bollw^orm -^ (Pccfinoplwra 

 gossypicUa ) 

 Order — Lepidoptera 



The parent is a small grayish-brown moth which 

 probably came from India or Africa and is now es- 

 tablished in Brazil, Mexico, and Hawaii; first found 

 in United States in 191 7 in Texas. 



Eggs are laid singly or in groups on bolls and 

 hatch in 4 to 12 days; the larv?e burrow in the bolls 

 and become mature in 20 to 30 days; pupal stage 

 passed inside of boll and lasts from 10 to 20 days; 

 life cycle 35 to 50 days, and there are from 4 to 6 

 generations a year ; winter is passed in larval stage. 



24 Quaintance and Brues — U. S. Bu. Ent., Bull. so. 



25 Bysck— U. S. Dept. Agr, Jr. Agr. Res., Vol, IX, p. 343. 



