HOW TO KNOW THE IMMATURE INSECTS 



Many prefer a shorter handle; a few strokes of a saw will take core 

 of that. 



2. Water Net. — The triangular dredge has some advantages over 



other types because 

 no matter which side 

 rests on the bottom 

 one of the blades 

 will cut into the 

 ground when the in- 

 strument is dragged. 

 Fig. 40. A triangular dredge. 



This dredge has a net of fairly close mesh, sturdy fabric. It may be 

 drawn behind a boat or the net may be rolled into a compact body and 

 thrown out to some distance from the shore then drawn back by its 

 long cord. In the absence of a dredge net, a garden rake can be used 

 to good advantage. The debris at the bottom of the water course is 

 dragged out on the bank and examined for the insects that are hiding 

 within it. As the water runs out of the debris the insects try to get 

 back to the body of water also. 



3. Sifter. — Any container with a wire- 

 mesh bottom will serve this purpose. The 

 size of the meshes in the screen depends 

 upon the size of the insects, but for gener- 

 al purposes eight meshes to the inch will 

 be found useful. Figure 41 shows a sift- 

 ing box which is good for collecting soil 

 insects. 



Several sieves with different sized meshes 

 will help separate the insect catch. The 

 process should not be rushed, but the water 

 turned on gently or many of the specimens 

 will be damaged. 



Fig. 41. Sifter: A, water; B, 

 screen; C, funnel; D-F, 

 screens, from coarse to fine; 

 G, water exit. 



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