Dec. is, 1920 Rice Weevil, {Calandr a) Sitophilus or yza 411 



sufficient food to enable them to develop to maturity. They have been 



reported to breed in rice, wheat, corn, hulled oats, millet, barley, rye, 



buckwheat, chickpeas, Job's tears {Coixa lachryma), acorns of several 



species of oak, galls of Phylloxera devastatrix on Hicoria pecan, and old 



cotton bolls. 



LIFE HISTORY 



The observations from which the following data are taken were made in 

 Orlando, Fla., during the year 1919 and the early part of 1920. Since 

 this weevil is of more importance in the southern States as a pest of corn, 

 the life-history records were taken from weevils breeding in corn. 



All stages of the rice weevil are active throughout the year in Florida. 

 The egg, larval, and pupal stages are somewhat prolonged during the 

 winter months, but there is no hibernation period, and oviposition con- 

 tinues throughout the year. 



The adult weevils appear on corn in the field as soon as it reaches the 

 roasting-ear stage and are often to be found in the markets at this time on 

 the ears presented for sale. It is not until the corn has become a little 

 firmer, however, that oviposition begins. When it has reached the firm 

 stage the female weevils oviposit in all parts of the grain that can be 

 reached with the proboscis and ovipositor, for at this time it is a simple 

 matter for the weevil to excavate an egg cavity, and the rate of oviposition 

 is much greater at this time than later when the corn has hardened. As 

 the kernels of corn become harder the majority of the eggs are laid in the 

 white starch part of the kernel that is found at the outer end as the kernel 

 is attached to the cob. With shelled corn the majority of the eggs are 

 deposited in the soft germ part near the tip of the kernel where excava- 

 tion is relatively easy. 



In the field the ears with tips protruding from the shucks, those with 

 loose, open shucks, or those with shucks that have been injured by the 

 corn earworm or some other agency are the first to be infested. Ears that 

 have a long, tight-fitting shuck that extends well beyond the tip of the ear 

 at the period when the corn is ripening are practically immune from weevil 

 attack. The weevils encounter great difficulty in penetrating a well- 

 developed, tight-fitting shuck and therefore congregate on the ears with 

 the damaged or poorly developed shucks. The kernels at the exposed 

 tip are the first to be infested, but the weevils soon work their way to all 

 parts of the ear. 



METHOD OF OVIPOSITION 



The female weevil after selecting a favorable spot on a kernel of corn 

 proceeds to excavate the egg cavity. This she accomplishes with her 

 powerful though slender proboscis or beak, oscillating her body in such a 

 manner as to impart a combined up and down and rotary motion to the 

 proboscis. The mandibles attached at the end of the beak chew away at 

 the corn until finally a hole is excavated equal to the length of the 



