334 



ELEMENTARY ENTOMOLOGY 



four feet long, with a double hook at one side and a brush at the other side 

 at its distal end. To illustrate the use of this apparatus, suppose we wish to 



collect the insects from the stones 

 obstructing a brook. We place the 

 net directly below the obstruction 

 and in the current, and adjust it to 

 the bottom by downward pressure 

 on the handle with one hand, while 

 with the other we rapidly overturn 

 the stone and with a brush sweep 

 free the clinging insects. These are 

 driven by the current into the net, 



FIG. 470. Sag net, hook and brush for col- 

 lecting in rapids 



(After Needham) 



when it is then lifted and emptied. 



An aquatic sieve net (Fig. 471). This net is intended to be used 

 in stagnant water or on sandy bottoms where there is but little 

 vegetation. The frame consists of a light steel rod, sides of heavy 

 tin or galvanized iron, and a bottom of fine brass or galvanized 



FIG. 471. An aquatic sieve net 

 (After Needham) 



wire netting. When provided with a long handle, this net may 

 be used from the shore, and is particularly recommended for 

 burrowing nymphs of aquatic insects. 



Rake net. The rake net consists of an ordinary garden rake, 

 with a stiff semicircle of wire fastened on the upper side of the 

 rake above the teeth. This should be braced to the handle with 

 another piece of wire. A net is then attached to the upper part of 

 the rake and around the semicircle of wire. This is very useful in 

 slightly weedy water, or where there is a large amount of debris 

 on the bottom. When the bottom of a pond or stream is raked, 

 the insects, nymphs, and small crustaceans are either entangled in 

 the debris and brought to shore, or, in trying to escape the rake 

 teeth, swim back into the net. The debris should be carefully 



