176 



Bulletin 87 



eggs are laid singly and not in clusters like the eggs of certain other 

 moths. The larva or worm hatches in the course of a few days, 

 and after feeding for a short time on the leaves it bores into squares 

 and bolls. When first hatched the bollworm is so small that in 

 feeding on a cotton square it makes only a very small hole. As it 

 passes from square to square and finally to the bolls, it eats larger 

 and larger holes and when full grown may make an opening a 

 quarter inch in diameter. The bollworms are very variable in color 

 and markings, including pale green, pinkish and dark brown as the 



Pig. 3 — Arizona wild cotton (Thurberia) grow- 

 ing in mountain canyon of Southern Arizona. 



ground color, with markings of green and brown. The cotton boll- 

 worm is the same as the corn ear worm and is found everywhere in 

 the country where either cotton or corn is grown. The female 

 moths may lay as many as 3000 eggs. They prefer to lay these on 

 the fresh silks of corn and consequently this crop may be used as 

 a "trap crop" for the protection of cotton. The bollworm also 

 breeds on alfalfa and attacks bean pods and green tomatoes, in the 

 latter case sometimes being known as the green tomato worm. 



The cotton bollworm passes the winter in a cell in the ground, 

 and fall and winter plowing of cotton and corn fields breaks up 

 many of these cells and exposes the pupae to destruction by birds 

 and rodents. Injury to cotton by the bollworm in Arizona has not 



