102 Journal Xew York Entomological Society. [Vol. xix. 



were now cut off, and shortly after the operation a honey-bee with 

 vibrating wings was placed upon the surface-film near the bug, 

 whereupon the latter responded by rapidly opening and closing the 

 claw-like tibia and tarsus of the front legs. The next morning the 

 surface-film near the aquatic bug was touched with a needle and the 

 same reaction was given. By repeatedly touching the surface-film 

 with a needle in front of this hemipteron deprived of its eyes, the 

 bug could be induced to swim towards the needle and at the same time 

 it would endeavor to grasp the source of disturbance. 



Flies with one wing amputated were dropped near Belostomas 

 resting at the surface of the water and were often seized so quickly 

 and so suddenly that the eye was unable to follow the exact move- 

 ments. If the bug was not hungry, however, the dipteron was able to 

 swim about upon the surface-film within easy reach of the raptorial 

 legs of Bclosto)iia without provoking any attempt to capture the Hy, 

 If a fly, swinnning on the surface of the water, happens to crawl upon 

 this hemipteron, it may stimulate the bug to swim away, leaving the 

 fly behind; or, if by chance, it reaches a position near the head of 

 Belostoma, it may be seized by one of the raptorial legs. Should the 

 fly be seized by one of its legs and endeavor to free itself, the other 

 raptorial leg of the bug will often clutch the victim around the body. 

 Bueno (lo, p. 191) has observed that at times all three pairs of legs 

 " are employed to hold fast some powerful insects or large victim, 

 such as a snail." Having obtained a good grip, the water-bug draws 

 the prey below its head to the beak. The fly may then be moved 

 about by the raptorial legs as the terminal end of the proboscis 

 touches the dipteron here and there, as if seeking a suitable place to 

 insert the piercing organ. While holding the prey with its front legs, 

 Belostoma proceeds to suck out the juices of its victim, and even 

 when disturbed will usually not drop the fly. but will swim about very 

 actively, retaining possession of its meal. 



At times, a Belostoma resting at the surface-film, will leave its 

 resting place without any apparent cause and begin to swim actively 

 about. If the hemipteron should happen to swim to the bottom of 

 the aquarium and by chance come to rest upon a dragon-fly nymph, 

 not too large, the bug may again enjoy a meal; for as the nymph 

 squirms about endeavoring to free itself of its burden, Belostoma 

 may clutch it tightly and sink its styliform mandibles and maxillae 

 into its victim. 



