THE DIODONTI. 99 



CHAPTEK X. 



The Diodonti. 

 Plates X., fig. 5; XIV., fig. 3. 



Along the fence that separates the garden from the woods be- 

 yond grows a row of choke-cherry bushes, among which are 

 mingled wild roses and the tall stalks of the yellow coreopsis, — 

 a touch of poetry amid the prose of beans and potatoes. It was 

 while passing these bushes one day early in July that we saw, 

 hovering over them, numbers of little black wasps. These were 

 the Diodonti, and closer inspection showed that they were busily 

 engaged in catching the aphides which swarmed on the under- 

 sides of the leaves. We were glad enough to seize the oppor- 

 tunity thus offered, and for this and several succeeding days we 

 devoted ourselves to the study of this fearless and friendly little 

 species. 



Diodontus americamts is one of the tiniest of all the wasps, 

 but having chosen for its prey something still smaller and weaker 

 than itself it never lacks good hunting. Yet the wasps and the 

 aphides were not the only actors in our modest drama of the 

 choke-cherry bushes. The ants were also on hand, solicitously 

 tending their little green cattle.. As might be expected they did 

 not look upon the destruction of the aphides with indifference 

 but gave practical proof of their interest in the matter by driv- 

 ing away the attacking wasps. Had they combined, and sent 

 out detaclmients to protect their flocks, the Diodonti might have 

 hunted in vain, for the wasps invariably had the worst of it in 

 their encounters with the ants; but their efforts were solitary 

 and did not count for, much, since a wasp that was driven from 

 one group at once settled down upon another. 



In Belt's '^Naturalist in Nicaragua" there is an interesting 



