June-Oct., 1921 Bulletin of the Brooklyn Entomological Society 97 



leaves. After several minutes, low down in the grass I saw a 

 robber fly with something in its grasp. Upon capturing it, the 

 something proved to be the Strymon titus, not only quite dead, 

 but with all of its legs torn off except the right fore leg. The 

 robber fly in this instance was also the same species as the one 

 just mentioned. " 



I observed this and other species of robber flies capture many 

 flies, but their prey was not confined entirely to such soft-bodied 

 insects as have been already mentioned, for I saw another robber 

 fly carrying its prey off, and upon following and capturing it the 

 victim proved to be one of the common beetles — Typocerus velu- 

 tinus Oliv. — which was dead ; although I do not know how long 

 the robber fly had had it, as I did not see its capture, the beetle 

 had just been killed, as it was quite limp. It would seem that a 

 hard-bodied insect of this character would make quite a tough 

 proposition for a robber fly to tackle. The fly in this case was 

 Dasyllis thoracica Fabricius. 



Probably the principal reason why so many robber flies infested 

 this particular spot was the fact that there were many sumac 

 bushes there in full bloom, and their flowers attracted swarms of 

 insects, butterflies, flies and beetles; and these in turn attracted 

 the robber flies. 



While collecting at Flushing, Long Island, N. Y., in August, I 

 noticed an Epargyreus tityrus Fabricius perched on a red clover 

 flower in a very unnatural position. Investigation proved it to be 

 dead and a small white spider, marked with maroon and olive 

 green, Misumena vatia Clerk, had it in its grasp. Its head was 

 at the butterfly's throat and its long front legs grasped the for- 

 ward part of the thorax, while with its shorter hind legs it clung 

 to the flower, from which it was with difficulty removed to the 

 killing bottle, and not until the cyanide fumes began to affect it 

 did it loosen its hold on the butterfly. This small spider was so 

 much inferior in size to the butterfly that it is amazing indeed 

 that it was able to grasp and hold, until it could kill it, such a 

 robust and strong flying butterfly as Epargyreus tityrus, unless it 

 injected into the butterfly some powerful secretion which quickly 

 benumbed it and stilled its struggles. 



