A BUG EEPORTED AS ENEMY OF BOLL WEEVIL. 53 



sia flowers spissipes fed upon Triphleps insidiosns^ a species of the 

 weevil genus Apion, man}^ thrips, and larvae and pupae of a cecidomyiid 

 gall-maker. 



Cannibalism. — Cannibalism occurs in this species, but is not com- 

 monly indulged in. On October 3 three specimens of Apiomerus spis- 

 sipes that had not fed since hatching were put in each of four pill 

 boxes, without food. The first death occurred October 7, the last 

 October 9. No instances of cannibalism occurred. Other experi- 

 ments with newl}^ hatched unfed nymphs gave the same result — no 

 cannibalism. October 1 twenty -two specimens hatched and were fed 

 upon insects found in heads of Helianthus. October 7 two nymphs 

 were observed eating a third, and again on October 9, 10, and 12 the 

 same observation was recorded. Other instances must have occurred 

 in the intervals between observations, which would account for the 

 death of individuals not apparently weak or diseased. It is evident, 

 therefore, that the species is cannibalistic, but it is apparent that the 

 first food must be obtained more easily than it could be by a contest 

 with one of its kind of equal age and strength. In nature, however, 

 where each individual goes upon a separate quest for food, it is very 

 unlikely that cannibalism is a serious menace to the species. 



LENGTH OF LIFE CYCLE. 



Owing to the abnormal conditions in the laboratory, which made it 

 very difficult to keep either 3^oung or old spissipes alive, the length of 

 the instars could not be gaged with certainty. The time between 

 copulation and oviposition varied from 4 to 7 days. Incubation 

 required 10 to 16 days, according to season. The third molt in one 

 instance occurred 12 days after the second, yet specimens have lived 

 more than a month after the second molt without molting. The 

 absences of the writer from the laboratory for a period of weeks at 

 times destroyed the continuity of the experiment, and made it impos- 

 sible to follow the life history as closely as was desired. However, 

 there can not be more than a fragment of the second generation in a 

 single season. Proper and improper food supply was undoubtedly the 

 cause of the great variation in the length of instars noted above. In 

 nature the same conditions of food suppl}^ undoubtedly exist, thus 

 making a difference of months in the maturity of individuals hatched 

 from the same ^gg mass. Observations in the field bear out this 

 conclusion. 



At no time during the year of 1905 could the young be found in any 

 numbers. Altho adults were frequently observed in copulation in 

 June and July at Gurley, later observations failed to disclose more 

 than a few young. It is reasonable to suppose that among the surviv- 

 ors that finally reached maturity some encounter almost perfect con- 



