228 THE NATURALIST IN NICARAGUA. [Ck XII. 



prey upon them, that I imagine that in the tropics many 

 species would be exterminated if it were not for the pro- 

 tection of the ants. 



Similarly as, on the savannahs, I had observed a wasp 

 attending the honey-glands of the bull's-horn acacia 

 along with the ants ; so at Santo Domingo another wasp, 

 belonging to quite a different genus (Nectar in a), attended 

 some of the clusters of frog-hoppers, and for the posses- 

 sion of others a constant skirmishing was going on. The 

 wasp stroked the young hoppers, and sipped up the 

 honey when it was exuded, just like the ants. When an 

 ant came up to a cluster of leaf-hoppers attended by a 

 wasp, the latter would not attempt to grapple with its rival 

 on the leaf, but would fly off and hover over the ant ; 

 then when its little foe was well exposed, it would dart 

 at it and strike it to the ground. The action was so 

 quick that I could not determine whether it struck with 

 its fore-feet or its jaws ; but I think it was with the feet. 

 I often saw a wasp trying to clear a leaf from ants that 

 were already in full possession of a cluster of leaf- 

 hoppers. It would sometimes have to strike three or 

 four times at an ant before it made it quit its hold and 

 fall. At other times one ant after the other would be 

 struck off with great celerity and ease, and I fancied 

 that some wasps were much cleverer than others. 

 In those cases where it succeeded in clearing the leaf, it 

 was never left long in peace ; for fresh relays of ants 

 were continually arriving, and generally tired the wasp 

 out. It would never wait for an ant to get near it, 

 doubtless knowing well that if its little rival once fastened 

 on its leg, it would be a difficult matter to get rid of 

 it again. If a wasp first obtained possession, it was able 



