52 PAPERS ON THE COTTON BOLL WEEVIL. ETC. 



It should be noted in these tables that while the nymph of Apiomerus 

 spissipes killed 50 pepper weevils, and Sinea diaderna 61 during the 

 same period, yet spissipes killed only 3 boll weevils, while Sinea killed 

 12. These results indicate that little benefit can be expected from 

 spissipes in the early stages. The boll weevil is too large for the 

 nymphs to capture easily, hence the choice of the smaller, pepper 

 weevils. It would appear also that a boll weevil diet is not a perfect 

 one, for in the experiments with boll weevils as food for adult sj>isx/pes 

 all died in a short time. One adult ate 27 weevils in thirteen days. 

 but died on the fourteenth day. Other experiments gave similar 

 results. The table shows also that Sinea does not prefer a diet of 

 boll weevils. It ate only 20 per cent as many boll weevils as pepper 

 weevils, altho active enough and strong enough to capture and kill 

 them easily. 



An adult Apiom,erus spissipes, under observation from June 1 to 

 July 3, ate 2 flies, 22 ladybirds. 1 bee. and 1 specimen of the twelve- 

 spotted cucumber beetle (Diabroticd M-punctaia Oliv.). but died* on 

 July 6. Another adult, under observation from June 10 to 21. when 

 it died, ate D. 12-pundata and a few ladybirds, but refused the potato 

 beetle {Leptinotarsa decern! i neat a Say) and its larvae and the sharp- 

 shooter (Homalodisca triquetra Fab.). 



Other adults throve for a time on house flies, but. like those fed 

 upon weevils, they could not be kept alive. Neither did any combi- 

 nation of the above foods produce any better results. 



Food of the young. — The impossibility of keeping the young alive 

 thru more than two or three instars leads to the conclusion that 

 proper food was not supplied them. On June 10 several specimens 

 of Apiomerus spissipes hatched and were placed in a cage and supplied 

 with cotton aphides (Aphis gossypii Glov.) in abundance. Altho fresh 

 food was supplied daily, spissipes fed very rarely, and on July 3 the 

 experiment was terminated by the death of the last of the nymphs. 

 Other experiments with the cotton aphis resulted as in the preceding. 

 October 3 a nymph Hearing the third instar was fed upon nymphs of 

 Pentatoma ligata. It ate 3 nymphs on the 3d and 4th. but died on 

 the 5th. A combination of ligata nymphs and cotton aphides failed 

 to keep another spissipes alive more than a few days. On September 6. 

 3 specimens of spissipes which had just hatched were isolated in a jar 

 containing the egg mass from which they came. On September 8 all 

 were dead. This experiment was made to determine whether the egg 

 mass furnishes food for the first instar. as is the case with some penta- 

 tomids. From this experiment, and a subsequent one which gave the 

 same results, it is evident that no food is obtained from the egg mass. 



The best results were obtained by breaking open heads of Ambrosia 

 in bloom and letting the Apiomerus spissipes nymphs select food from 

 the insects frequenting this flower. Among the insects found in Ambio- 



