51 



tinues its normal coarse of development. When feeding punctures 

 are made in squares which are nearly ready to bloom, the injury com- 

 monly produces a distorted bloom (PL VII, fig. 32) and in very severe 

 cases the boll will drop soon after setting. 



After the females begin to oviposit their feeding habits become 

 quite different from those of the males. Up to this time both sexes 

 move but little, making a number of punctures in a single square; 

 but from this point we must consider the feeding habits of the sexes 

 separately. 



MALE. 



Studies of the feeding habits of males have been made both in the 

 laboratory and out of doors. '" In the laboratory 65 males were under 

 observation during a total period of 2,492 weevil-da} 7 s. a During this 

 period 2,185 squares were supplied them and they made 5,617 feeding- 

 punctures in 1,582 of these squares. A little calculation shows that they 

 averaged to make 3J feeding punctures in each square, at the rate of 2i 

 punctures a weevil each day. These observations were in most cases 

 made during the latter part of each weevil's life. During the first few 

 days they have often been found to make from 6 to 9 punctures a day. 

 A general average of 3 feeding punctures a day in the laboratory 

 would seem to be near the actual figures during the warm weather. 



As each male while under observation attacked only about 2 squares 

 every 3 days, the destructiveness of males seems comparatively slight. 

 As will be seen in the following paragraph, the injury done by males 

 in the' field is not greater than that indicated by the laboratory obser- 

 vations. 



Five males were followed upon plants under a field cage for a total 

 period of 115 weevil-days. During this period they attacked 68 

 squares, making therein a total of 177 feeding punctures. This 

 means an average of 2.6 punctures per square and an average of 1.2 

 punctures per male per day, making the number of squares attacked 

 by each male less than 1 every 2 days. These outdoor observations 

 indicate that the laboratory results, small though they appear, are 

 yet higher than the actual field numbers. Whether in or out of 

 doors, the activity of feeding decreases as the male grows older. 



Males choose to puncture more often than do females through the 

 tip portion of the square not covered by the calyx. The yellow or 

 orange-colored excrement is abundant, and owing to the somewhat 

 sedentary habits of the males it accumulates often in quite large 

 masses, so that it is often possible to tell whether a square in the field 

 has been attacked by a male rather than a female weevil. 



«The term "weevil-day" is used for convenience to designate the product of the 

 two factors: number of weevils multiplied by the number of days. 



