April, '11] HINDS & turner: rice weevil 235 



first infested and later those near the butt of the ear. The female 

 eats out a cavity large enough for the egg, occupying usually about 

 forty-five minutes in the operation when the corn is fairly hardened, 

 then turns, locates the cavity with the tip of the abdomen and inserts 

 the fleshy ovipositor. The deposition of the egg requires only about 

 three minutes and the cavity is then sealed over as the ovipositor is 

 withdrawn. The top of the egg is just below the surface of the grain. 

 The female will then rest for a short period before starting another 

 cavity. Conditions are most favorable for both the adult and the 

 young when eggs are deposited in corn which has just passed the 

 "dough" stage. In this condition the grain can be cut with the thumb- 

 nail and may be characterized as a "hard gum" stage. All corns, no 

 matter how hard they may become later, must pass through this 

 stage durijig which they are subject to attack if weevils have access 

 to the kernels. Long, clo^e-fitting shucks may serve to so retard weevil 

 entrance that the grain may harden and become more resistant to 

 subsequent injury. 



Rate of Oviposition. — This is a point upon which we have had no 

 previous data. It has been interesting to find out the factors afiiecting 

 the rate of egg deposition. Most important of these is evidently the 

 degree of hardjiess of the kernel. With corn in the "gum" stage, the 

 maximum record obtained was twenty eggs in twenty-four hours. 

 Daily records of fifteen or sixteen eggs were not uncommon, while the 

 average through a period of several weeks, with a number of weevils, 

 was about seven eggs per day. Weevils which were laying ten or 

 twelve eggs per day on "gum corn" would be checked to two or three 

 eggs per day on hard corn. 



The period of oviposition is nearly as long as the life of the female, 

 beginning within a few days of her emergence from the grain. Eggs 

 may be deposited until within a few days of death. The maximum 

 oviposition period yet found is 110 days, but this female is still active 

 at this writing. During this period 417 eggs have been deposited. 

 Still another weevil deposited 374 eggs in the laboratory in addition 

 to what she may have deposited in the fields before she was captured. 

 The maximum record, however, includes the entire deposit as the 

 weevil was bred. 



Life Cycle and Generations. — The average duration of the life cycle 

 during August and September is between seven and eight wrecks. 

 Generations, therefore, become wholly mixed within a short time. 

 It appears, though, that about three generations are developed on 

 early maturing corn before the middle of December and two genera- 

 tions with medium late corn. Infested corn, which has been kept in 

 receptacles in the laboratory has shown but two generations for the 



