87 



find enough uninfested squares to lead them to deposit so many eggs, 

 but the possibility remains if only squares enough are present. 



A few words must be said in further explanation of the differences 

 which appear between the field and laboratory results. In the case 

 of the laboratory figures the entire oviposition period of each weevil 

 and the entire number of eggs deposited are taken into the account. 

 As there is a gradual increase in the rate of production of eggs after 

 the beginning of deposition and a gradual decrease from the middle 

 of the period to its end, the general average is much lower than would 

 be that taken at the time of maximum activit}^. In the case of the 

 field figures a short period only is covered, and all conditions of square 

 supply were such as to stimulate the weevil to its greatest normal 

 activit}^. 



MAXIMUM. 



The daily observations made upon the weevils in the laboratory 

 supply a vast number of observations from which to select maximum 

 figures. It has been shown that under favorable conditions weevils 

 may be expected to produce an average of 6 eggs a day for a consid- 

 erable period of time. It is not surprising, therefore, that some of the 

 maximum figures obtained are very much larger than that number. 

 A few instances only will be taken from among thousands of daily 

 records. 



The highest record of eggs deposited shows that 2 small females 

 deposited together 108 eggs in 3 days, or at the daily rate of 18 eggs 

 each. This record was made on the 7th, 8th, and 9th of June, 1903. 



Table XX. — Maximum rate of oviposition. 



Number 



of 

 females. 



Days in- 

 cluded 

 in period. 



Total 

 eggs de- 

 posited. 



Average 

 per day. 



Number 



of 

 females. 



Days in- 

 cluded 

 in period. 



Total 

 eggs de- 

 posited. 



Average 

 per day. 



2 

 1 



2 

 5 

 2 



3 

 5 



5 

 1 

 2 



108 

 76 



160 

 55 



47 



18.0 

 15.2 

 16.0 

 11.0 

 11.8 



2 



1 

 2 

 3 

 5 



2 

 3 

 5 



2 

 1 



43 

 30 

 114 

 54 

 42 



10.8 

 10.0 

 11.4 

 9.0 



8.4 



12 



1G 1 446 



13.5 



13 



13 



283 



9.5 



STIMULATING EFFECT OF ABUNDANCE OF SQUARES UPON EGG 



DEPOSITION. 



Four actively laying females were confined together upon a few 

 squares from September 22 till October 14, 1902, and during this 

 period they laid a total of 227 eggs, or an average of 2.37 eggs per 

 weevil per day. For the next 13 days these same weevils were isolated 

 and supplied with an abundance of squares. During this shorter 

 period they laid 236 eggs, or 4.51 eggs per female daily. 



