142 APPLIED ENTOMOLOGY 



for depositing eggs. As long as a large supply of squares is present, the 

 bolls are not damaged to any serious extent. The bolls, therefore, have 

 a fair chance to develop as long as squares are being formed." (Marlatt, 

 Farmers' Bulletin 848, U. S. D. A., 1917). 



TheSe insects are extremely prolific. It has been calculated that from 

 a single pair of the beetles in spring there might be 12,755,100 progeny by 

 the end of the season, but many factors prevent this from actually being 

 the case. Infested squares soon drop off the plant and on the ground 

 generally become so heated as to kill the larvae in them. Parasites and 

 other enemies, particularly ants, attack the insect, and other minor 

 factors are of some value. All of these combined, however, only prevent 

 a bad condition from becoming worse, and control measures must be 

 resorted to. 



Control. — There are several control measures which seem to give par- 

 tially satisfactory results. One of these is to destroy all infested plants in 

 the fall, particularly in the southern part of the area where the weevil is 

 found. This kills great numbers of adults about ready to hibernate, many 

 more still in early stages in the plants, leaves no food for those escaping, 

 and prevents the production of the latest beetles, thus reducing the num- 

 ber to hibernate. It also permits fall or winter plowing which is good 

 farm practice in cotton growing. Generally this destruction of the plants 

 should occur in October, even though a little cotton is lost in this way. 

 The destruction of any hibernating weevils wherever possible is advan- 

 tageous. Crop rotation is also desirable, as many of the weevils winter 

 near the cotton fields and do not fly far in the spring. Any methods 

 which will hasten crop production, such as fertilizers, the use of 

 early maturing varieties and early planting, are desirable. Dusting 

 the young plants with arsenate of lead or arsenate of lime blown 

 directly onto them has frequently given good results. The use of all 

 these methods together gives considerable relief from the attacks of this 

 pest, and the problem how far to go in carrying them out is largely one of 

 their cost as compared with the value of the cotton which will be saved by 

 the treatments. Hand picking of the weevils and of infested squares has 

 not generally proved successful. As the insect has thus far been known to 

 feed only on cotton and the wild cotton of Arizona (where it probably 

 does not yet occur), the danger of its increasing on other food plants does 

 not at present seem to exist. 



The White Pine Weevil (Pissodes strohi Peck). — This native enemy of the 

 pine occurs practically wherever the white pine is found, viz., from New Bruns- 

 wick and Canada west to Minnesota, and south to North CaroUna. It also 

 attacks our other native pines and the spruces somewhat. 



The adults (Fig. 136) pass the winter in protected places, possibly in the 

 ground, and in spring gather on the terminal shoots (leaders) of the pines, generally 

 on the trunk leader in preference to those of the branches. Here, near the tip, 



J 



