200 



COLEOrr ERA— BEETLES 



progress throughout the cotton-growing States. It is a small 

 beetle somewhat like the clover weevil but restricted to the 

 cotton plant for its food and for the early stages is restricted 

 to the bolls of cotton for its particular food. This means 

 that it can develop only in places where cotton grows and 

 at such time as the cotton bolls are in process of develop- 

 ment. This species has practically revolutionized the agri- 

 cultural conditions of the Southern States in which it has 

 spread, and it is unnecessary to say that it must have had 



Fig. 150. — White-pine weevil {Pissodes strohi): a, adult, smaller figure 

 natural size; h, larva, line at left natural length; c, pupa, small figure of 

 adult showing natural size. (Hopkins, Div. Ent., U. S. Dept. Ag.) 



a very pronounced influence upon the other kinds of insects 

 or animals that occur in that region. 



The ma]:» illustrates its progress from year to year and it 

 is a matter of considerable interest antl significance that 

 the northern border of its distribution has remained inside 

 the jjossible area of cotton growth. It may also be noticed 

 that this line agrees remarkably for the northern distribu- 

 tion of the cattle tick and other insects which are of tropical 

 derivation. 



