844 INSECT WATER TRESPASSERS. 



the Water Boatman is hungry, it goes in search of some 

 unfortunate insect ; and having overtaken it, clasps it 

 in its fore legs, and draws it tightly against its head, 

 by the same action driving the proboscis into it. The 

 juices are then sucked, and when they are exhausted, 

 the Water Boatman throws off its now useless prey, and 

 goes off in search of another. 



I have often watched these Water Boatmen em- 

 ployed in capturing and killing the water gnats which 

 may be seen traversing the surface of any still river or 

 pond. The water gnat is active, but seems to be 

 powerless against the Water Boatman, which rises from 

 below, clasps the unfortunate insect, and almost before 

 the eye can detect its movements, has the proboscis 

 buried in its body. 



The time occupied in sucking an insect varies 

 considerably. I have often watched the process, and 

 have found that, whereas in some cases five minutes 

 is enough for a water gnat to be sucked dry, in another 

 case the operation lasts for a full quarter of an hour. 

 I apprehend that the difference of time is caused by 

 the greater or less hunger of the captor. 



Although the Water Boatman is not a large insect, 

 the proboscis is strong and sharp enough to inflict a 

 severe prick upon the human hand. I fancy that in 

 some species, at all events, some kind of a poisonous 

 fluid must be injected into the wound. There is one 

 'of these insects belonging to the genus Corixa, which 

 is as large as the present species, but wider and flatter. 

 I have more than once been pricked by the proboscis 

 of the Corixa, and have always found that the sharp 

 smart of the prick was followed by a dull aching pain, 



