57 



noted in each case, so far as was possible, were : The formation of a 

 distinct wart; time of flaring, yellowing, and falling; the emergence 

 of adult; presence of a parasite; death of larva, pupa, etc. A verj^ 

 complete history of each square was thus obtained. During the sea- 

 son of 1903 three special periods were selected for study of this kind. 

 The first was taken during the early i)art of June, when hibernated 

 weevils only were active, the second was taken in August for the 

 work in midsummer, and the third in the latter part of October for 

 the study of the development of late weevils. Altogether in these 

 three series over a thousand squares were tagged and recorded. The 

 work of males was compared with that of females in this way, as 

 were also the developmental periods in squares and bolls. Although 

 requiring a great deal of time and close attention, the numerous defi- 

 nite observations obtained abundantly justified the work required. 



FERTILIZATION. 



AGE OF BEGINNING COPULATION. 



After the adult weevils have left the squares a certain period of 

 feeding is necessary' before they arrive at full sexual maturity. This 

 period varies in length according to the effective temj)erature prevail- 

 ing and api^ears to bear about the same ratio to the developmental 

 period as does the pupal stage. 



Among the many weevils kept from emergence till deatli for the 

 purpose of ascertaining the length of life without food, copulation 

 was never observed. With weevils fed upon leaves alone the period 

 preceding copulation is about twice the uornuil length in the cases 

 observed of those having squares to feed upon. 



During the hot weather this period appears to be on the average 

 only about three or four days in length, while as the weather becomes 

 colder it increases gradually until weevils may become adult, feed 

 for a time, and go into hibernation without having mated. A single 

 union seems to insure the fertility of as many eggs as the average 

 female will lay, and its potency certainly lasts for a period fully equal 

 to the average length of life. 



SEXUAL ATTRACTION AND DURATION OF COPULATION. 



The distance through which the attraction of the female will influ- 

 ence the male varies extremely. To ascertain how far the attraction 

 might be exerted in the case of the boll weevil, 2 females were con- 

 fined with food in a small bottle covered with cheese cloth, and the 

 bottle was then placed in a horizontal position inside a field cage and 

 near its top. Within this cage were 3 males which had been confined 

 there alone for 4 weeks. The bottle containing the females was so 

 placed as to be within a few inches of the top of a cotton plant upon 



