NATURAL CONTROL. 75 



peared to recover slowly. By July 22 the colony had completely 

 resumed its normal condition and the mites had been exterminated. 

 That the Pediculoides could live and breed upon the ant larvae was 

 established by placing the latter in a glass dish which was isolated 

 from all workers and permitting them to become infested. On them 

 tlie Pediculoides grew and increased as well, apparently, as on wasp 

 and other larvae. Such enormous cultures of the mite as were intro- 

 duced into the ant colonies in these experiments could not possibly 

 occur in nature, and it seems a safe conclusion that this parasite can 

 make no headway against the ant under normal conditions. 



EXPERIMENTS WITH FUNGOUS DISEASES. 



During 1909, at Baton Rouge, several experiments were made in 

 the attempt to moculate the ants and their larvse with the chinch-bug 

 fungus, Sporotrichum glohuliferum . Cultures were prepared from 

 beef extract and corn meal, sterilized at a pressure of 18 pounds per 

 square inch for 30 minutes at a temperature of 256° F., and these 

 were then inoculated with the fungus from a dead beetle. After these 

 cultures had been stored for about a week in a dark, damp place, 

 they all showed a heavy white layer of fungous growth over the sur- 

 face, and this layer was used in the experiments. 



Large cjuantities of this fungus were placed in Janet cages which 

 contained strong and healthy colonies of ants with many immature 

 stages. For a short time the workers would busy themselves carry- 

 ing out the fungus and dropping it over the side of the cage support, 

 but after a time they apparently became accustomed to its presence. 

 It grew and increased mside the apartments in which the ants and their 

 young stages were domiciled until it formed a heavy white mass over 

 nearly everything, but in not a smgle instance was an ant or a young 

 stage observed which appeared to be in the least inconvenienced by it. 



As a number of dead ants were found covered with fungi the 

 various organisms on them were isolated and cultures made. The 

 principal fungi obtamed were Aspergillus and Penicillium. Cul- 

 tures of these were also introduced into the ant colonies, but without 

 effect. It was therefore concluded that they were purely sapro- 

 phytic on the dead ants on which they were found. 



Attempts were also made to infect colonies with Bacillus larvae, 

 the germ causing the disease among honey bees known as American 

 foul brood. Owing to the fact that this bacillus attacks the larval 

 stages of the honey bee, and considermg the similarity of ant and bee 

 larvae, it was thought that this disease might attack the larval stages 

 of the ant. The experiments were made in a locality where the ant 

 infestation was very heavy but where honey bees were not kept. 

 Honey was thoroughly mixed with broken and mashed brood combs 

 containuig bee larvae badly infected with foul brood, and this honey 



