WELCH J HATER IX SECTS 183 



The Water Striders (Fig. 6). 



Among the very first insects to appear in the Spring are the 

 Water Striders. They are oval, dark-bodied insects with long 

 spider-like legs and are to be seen on almost every pond or 

 stream, running about with swift nervous movements over the 

 surface of the water. They are held up by the surface film in 

 which their feet make distinct dimples. These dimples, on sun- 

 shiny days appear as shadows on the bottom. Often they rest 

 idly on the surface and drift with the current or before the breeze. 

 If the young collector examines his collecting grounds carefully 

 he will probably find them in every aquatic situation, in open 

 water, or among the half submerged vegetation, or among the 

 floating lily pads, or even running over the muddy banks close to 

 the water's edge. The second and third pairs of legs support the 

 body while the first pair, which the beginner may not recognize 

 as legs, are used as grasping organs. The immature Water 

 Striders are like the adults except that they are a little smaller 

 and the abdomen is very short. Watch these insects with an 

 opera or field glass and many facts about their behavior will be 

 discovered. They prey upon other small insects, seizing them with 

 the fore legs, piercing them with their sharp beaks, and sucking 

 their juices. They are usually ver\' shy and quick, and in order 

 to collect them one must approach them very cautiously and 

 quietly and then scrape them up with a sudden dash of the net 

 which should just sweep the surface of the water. Watch that 

 they do not leap out of the net before they are secured. Carry 

 them home in a closed pail containing some wet water weeds. 

 They may be drowned if shaken about in a closed pail of water. 

 Handle them with care as they can inflict rather severe pain with 

 their sharp beaks. They are easily kept in an aquarium which has 

 sides high enough to prevent them jumping out. Feed them by 

 throwing in a few dead flies. Do not use flies which have been 

 killed in a cyanide bottle, as they are poisonous. Do not put 

 larger water insects of a different kind into the same vessel. 



The Marsh Treader (Fig. 7). 



This queer little insect is usually overlooked since it is only 

 about one-half inch long, dull dirty brown in color, and quiet in 

 habits. It is found at any time during the Spring or Summer 

 on the surface of the water or on the soft mud of the shore where 

 there are plenty of water plants growing. It seems to prefer 

 swamps and stagnant pools. It has long thin legs, hair-like 



