50 INSECTS AND MAN 



its rapid distribution is not the cause of wonderment even 

 to the least observant, as is the case with those essentially 

 stationary insects the coccids, or such semi-stationary ones 

 as the gipsy moths. A certain amount of dispersion takes 

 place in the spring and summer, but it is in the autumn 

 that the more or less annual advance over the cotton belt 

 takes place. The dispersion may be put down as an over- 

 flow from territories so overcrowded that there is a scarcity 

 of food, and no opportunities for breeding, combined with 

 a strong instinct to invade new regions. The direction of 

 this great autumn flight is usually governed by the pre- 

 vailing winds, and the distance travelled is regulated by the 

 occurrence of uninfested cotton. If the first short flight 

 reveals cotton as yet unattacked, the weevils will settle 

 there; if, on the other hand, infested cotton is found or 

 none at all, a series of flights will take place, till the beetles 

 find the cotton they are seeking. Sometimes these flights 

 will carry them as far as forty miles. In the cotton-fields 

 the boll weevils are well protected from their enemies by 

 their colour, which harmonises well both with the dry 

 cotton squares and the soil on to which they frequently 

 fall. When the plant on which the weevil is feeding is 

 disturbed, or even if a large object moves in its vicinity, the 

 insect becomes all attention, remaining motionless, with its 

 antennae raised. If the disturbance continues, the weevil 

 falls to the ground, withdraws its antennae against its beak, 

 which, together with its legs, are drawn close to its body. 

 Thus it remains "shamming dead" for some time, unless 

 further disturbed, when it will take to its legs and run a 

 short distance before repeating the performance. 



It is only natural that a considerable amount of attention 

 has been paid to the control of such a pest as the boll 

 weevil has proved itself. Climatic conditions have, so far, 

 proved the most effective agency in keeping the insect 

 within anything approaching reasonable bounds. Winter 

 cold and summer heat alike are injurious to the insect, the 



