96 Annals Entomological Society of America [Vol. XI, 



twig so that the ants pass by them. Ants appear to be unable 

 to detect the presence of the bugs at a greater distance than 

 one centimeter. If one happens to get this close it immediately 

 attacks the bug, but it is doubtful if it ever succeeds in catching 

 one. 



In consideration of the poor visual powers of the ants and 

 the helplessness of the aphids, it is hard to imagine how the 

 striking resemblance of Pilophorus to the ants, with which they 

 are often associated, can be of any value to the species either 

 for protection or aggression. The only logical conclusion seems 

 to be that the resemblance is purely accidental. 



