6 



FARMERS BULLETIN 872. 



bore into the growing tips of the plants and occasionally destroy 

 the flowers as well. 



In tobacco the injury consists of the penetration of the small leaves 

 in the growing tip, hence the common name of budworm. A related 

 caterpillar/ however, attacks tobacco in a very similar manner. A 

 single caterpillar may render several leaves unfit for wrapper by 

 penetrating the bud. 



HABITS OF THE INSECT AND HOW IT DEVELOPS. 



A general knowledge of the life history and habits of an insect is 

 needed in order intelligently to combat it. The bollworm or corn ear- 

 worm Mhen mature (fig. 4) is a moth or miller about IJ inches across 



the spread wings. It varies in color 

 from a light brow^i or olive green to 

 pale yellow and it is commonly seen 

 flying about in the evening. These 

 moths feed upon nectar of various 

 flowers and when mature they de- 

 posit from nearly 500 to almost 3,000 

 eggs. The eggs (fig. 5) are laid on 

 various parts of the plant and to 

 some extent upon weeds and upon 

 the ground. They are white or yel- 

 lowish in color, oval, and covered 

 with minute ridges running from 

 Bollworm moth with wings top to bottom and Still Smaller 

 position, .ibout ri(jges across these. They are large 



(Quaintance.) r, i. i ^■^ -^i j.i 



enough to be seen readily with the 

 naked eye. The eggs hatch in from 2| to 8 days or even longer, de- 

 pending upon the temperature. 



When first hatched the larvae or caterpillars are extremely small. 

 They feed here and there on the surface of the plant near where the 

 eggs were laid, but gradually work to- 

 ward some tender portion within which 

 they can bore. Growth is rather rapid, 

 being completed in about 20 days. The 

 larvae shed their skins four or five times 

 during this period. When full grown 

 they are about H inches in length. The 

 color varies from pale green to almost 

 black. During the last few days of the life of the caterpillar it is 

 capable of consuming large quantities of food, and it is during 

 this period that it is most destructive. 



Fig. 4 



folded in natural 

 twice natural size. 



Fig. 5. — EgK of bollworm moth, 

 side and top views. Highly 

 magnified. (Quaintance and, 

 Brues.) 



Known scientiflcall.v as Chloridea virescens Fab. 



