ANT COMMUNITIES 



are used to some such social phenomena among men, 

 who seem to have a perverse strain that forces their de- 

 velopment along aberrant lines toward disadvantageous 

 and destructive ends. But in these simpler children of 

 nature such conditions surprise us as quite abnormal. 



Once in a while, however, the ants do seem to shake 

 off the spell that binds them and awake to the true 

 nature of their guests. In one of Professor Wheeler's 

 artificial nests of Pheidole instabilis the workers rose 

 upon the adult Orasemas, after they had remained in 

 the nest several days, and killed and dismembered them. 

 But a doubt remains as to whether this was due to their 

 discovery that the victims were predatory aliens, or to 

 some special stress of hunger or other cause; for the 

 ants also killed and dismembered their own females, 

 and after that reared only their fellow - workers and 

 intermediates, as though they purposed to spare none but 

 the caste that furnishes the lightest consumers and the 

 helpers, and to free themselves from mere dependents. 

 Like action on the part of worker-ants of other species 

 has been known in times of special stringency in the 

 food supply. 



Another of the parasitic aliens that associate them- 

 selves with ants is a little Dipteron fly, Metopina pachy- 

 condylcc Brues. While sorting out a number of larva? of 

 a large black Ponerine ant, Pachycondyla harpax, several 

 were found to have larvae of the above insect attached to 

 the region of the first abdominal segment. It quite en- 

 circled the ant larvse, like a collar about the neck, "a 

 kind of Elizabethan ruff." The posterior end of the 

 parasite was provided with a sort of suction disk, by 

 which that part could clasp its host so tightly that the 

 fore part of the body could be released and swung out 



236 



