﻿THE GBANARY WEEVIL 21 



days between June 23 and September 25, when she died, although 

 the temperature means for this period ranged from 68° to 88° F. 

 and averaged well above 70° F. This female, which began oviposit- 

 ing on January 28, was therefore nearing the end of her life; still 

 she deposited but one egg on each of 120 oviposition days, two eggs 

 on each of 31 oviposition days, and three eggs on each of 5 oviposition 

 days. 



In the absence of definite data on the normal larval mortality, 

 it is believed to be rather high, and this is thought by the writers 

 to account for the somewhat higher daily rate of oviposition recorded 

 in Table 3 as compared with the conclusion of Strachov-Koltchin (65). 



DURATION OF OVIPOSITION 



The duration of the oviposition period is influenced by several 

 factors and varies considerably. (See Tables 2 and 3.) Those 

 adults that emerge late in the season and commence egg laying in 

 the fall have a long oviposition period. They cease ovipositing on 

 the approach of cold weather and commence again in the spring, 

 during February or March. Thus weevil No. 3, of Table 3, emerging 

 on September 5, began ovipositing September 15, and oviposited 

 almost daily until September 28, when she ceased laying until March 

 10, only to resume egg laying and to continue it almost daily until 

 June 1, ceasing entirely on June 12. This record of duration of 

 oviposition of 270 days is second only to that of 287 days, August 27, 

 1920, to June 10, 1921, by a female depositing 254 eggs. (No. 8, 

 Table 2.) 



Adults emerging in the spring have a shorter oviposition period, 

 because they deposit aU their eggs during a single season. The 

 shortest oviposition period recorded in Table 3 is 67 days. Weevil 

 No. 9, March 19 to May 25, 1922. Weevil No. 11 of Table 3, 

 depositing a total of 197 eggs, emerged on October 25, 1921, but did 

 not begin ovipositing until January 28, 1922, after which she laid 

 eggs with considerable regularity until September 24, 1922, thus 

 having an oviposition period of 239 days. Weevil No. 8, with an 

 egg-laying capacity of 242, emerged November 7, 1921, began ovi- 

 positing February 18, 1922, and continued until August 6, 1922, an 

 oviposition period of 169 days. 



Ihe average length of the oviposition period for adults emerging 

 during the spring and early summer is between three and four months. 



NUMBER OF EGGS DEPOSITED BY SINGLE FEMALES 



The data of Strachov-Koltchin, which are the only data previously 

 published on the eg^-laying capacity of the granary weevil, were 

 obtained with promiscuously captured females. From 11 females 

 he secured 65, 78, 87, 107, 116, 121, 129, 135, 149, 153, and 167 eggs 

 respectively. But he concludc^d tliat "since the females used were 

 in most cases not young, it is possible to assume that a normal num- 

 ber of eggs deposited by a single fcjuuh^ diu-iiig her life is 135 to 167." 



The 24 f(;males of known ag<'s, (lie ov^iposiiion ict^oids of which are 

 given in Ta})lc 3, deposited totals of 36, 65, 71, 74, 78, 95, 98, 108, 

 114, 126, 128, 130, 130, 135, 115, 166, 177, 181, 18-4, 197, 200, 210, 

 234, and 242. The largest nundxT of eggs (h^positcd l)y any single 

 female recorded is 254 CJ'able 2, No. 8). In 'J'ahh? 2 are recorded 

 the total numb(TS of eggs deposited by 35 IVinalcs, the daily oviposi- 

 tion records of 24 of whicli are given in Tabh; 3. 



