36 



ness of the season, together with the full-fed condition of the weevils, 

 seemed to promise a considerably longer period than 6 days. 



In the third series the 18 weevils used were 1 month old and full- 

 fed at the beginning of the test in the middle of November. The con- 

 ditions in this series were as in the series preceding, with the excep- 

 tion that an abundance of two species of grass taken from cotton 

 fields was included. These weevils showed an average length of life 

 of nearly 1\ da} T s, ranging from 3 to 10 days. The weevils made no 

 effort to feed upon the grass, so the slightly longer life period must 

 be due to other causes. 



CANNIBALISM. 



It is hardly proper to speak of cannibalism as a food habit of the 

 boll weevil, but the facts observed may well be recorded here. Under 

 the impulse of extreme hunger weevils have several times showed a 

 slight cannibalistic tendency. 



Seven beetles were confined in a pill box without food. On the 

 third day 6 only were alive. Of the seventh only the hardest chitin- 

 ized parts (head, proboscis, pronotum, legs, and elytra) remained, the 

 softer parts having been eaten by the survivors. 



In another box containing 12 adults the leaf supplied for food was 

 insufficient, and on the fourth day 8 were dead, 4 were partly eaten, 

 and others had lost one or more legs each. 



In another case a few young adults and a number of squares con- 

 taining pupse were placed in a box together with a few fresh squares 

 to serve as food for the adults. When the box was opened after a 

 number of days, one "reddish-brown" adult was found having its 

 elytra eaten through and most of its abdomen devoured. In spite of 

 this mutilation the victim was still alive and kicking slowly. The 

 squares were still fresh and fit for food, so that this is really the clear- 

 est case of cannibalism observed. 



Frequently more than one larva hatches in a square, and when this 

 is the case a struggle between them is almost certain to take place 

 before they become full grown. Many cases have been. observed in 

 which squares contained one living and one or more smaller dead 

 larvge, while in a few cases the actual death struggle was observed. 



HABITS. 



Among the habits of any insect of economic importance, the first 

 for careful study are those relating to its food, and secondly those 

 connected with its propagation. The study of the life history of the 

 boll weevil has revealed no especially vulnerable point, but rather the 

 important fact that in all its stages it is better protected against the 

 attacks of enemies and the ordinarily effective remedies recommended 

 by the economic entomologist than any other insect which has ever 

 threatened the production of any of the great staple crops of this 



