Dec. is, 1920 Tamarind Pod-Borer, Sitophilus linearis (Herbst) 443 



PREOVIPOSITION PERIOD 



Copulation takes place soon after emergence, and the females deposit 

 their first eggs in from 7 to 10 days after attaining adult form. Copu- 

 lation is frequent and often takes place while the female is at work on the 

 egg cavity. 



OVIPOSITION PERIOD 



The longest oviposition period recorded lasted for 84 days, and during 

 this time 183 eggs were deposited. Toward the latter part of this 

 period fewer eggs were laid than at first, the female becoming more and 

 more feeble and exhausted. Three weeks after the last egg was laid the 

 female died. The male died a few days later. 



Other female weevils in captivity deposited from 126 to 165 eggs. 

 It seems probable that under natural conditions with an abundant 

 supply of fresh seed the oviposition period would be longer and the 

 number of eggs deposited would be correspondingly larger. 



HABITS OF ADULT 



The males are, as a rule, slightly more abundant than the females. 

 Of 488 bred specimens, 258, or about 53 per cent, were males. The 

 males apparently feed but seldom, spending their time in constant 

 attendance on the working females or in fighting among themselves for 

 the females. They are of a very combative nature, and it is not un- 

 common to see two and sometimes three males fighting together for 

 hours at a time with apparently great ferociousness. As they have no 

 efficient or deadly weapons, however, little damage is done; and long 

 before a decision is reached another male has assumed the care of the 

 female, who, intent only on her work, is oblivious to the struggles of the 

 aspiring males. The males are readily distinguished from the females 

 by their shorter, thicker beaks. The beak of the male is considerably 

 broader at the base than that of the female. The adults in captivity 

 have fed on acorns, sweet potatoes, and various fruits. Normally, 

 however, they do not attack anything but the tamarind seeds. 



PARASITES 



No parasites have been reared from any of the stages of Sitophilus 

 linearis. Larval and pupal stages in the laboratory were attacked and 

 killed by a predacious mite, Pediculoides ventricosus Newport. It seems 

 very doubtful, however, that -this mite would be able to penetrate to the 

 larval burrows under field conditions. 



DESCRIPTION OF IMMATURE STAGES 

 EGG 



The egg is opaque, white, shining, ovoid to pear-shaped, rounded at 

 the bottom; the top is slightly flattened and narrower, fitting into a plug 

 or cap that cements it into place. The shell of the egg is very delicate 

 and flexible, conforming to the shape of the egg cavity. Its length is 

 0.60 to 0.64 mm., the width 0.31 to 0.35 mm. 



