HOW TO KNOW THE IMMATURE INSECTS 



6. Sifting. — Rinse the aquatic plants or bottom mud in a sifter. Many 

 insects can be collected on the screens of the sifter (See Fig. 41). Sub- 

 terranean insects may be easily secured by running the ground litter 

 or soil through a sifter. 



7. Separating. — Field soils, debris and animal nests or discharges can 

 be put in a separator with a light on the top for heating. Some sepa- 

 rators employ a stream of water to remove the insects from the debris. 

 A good number of unusual insects may be collected in the receptacle. 

 Those insects are usually small and active, or they feign death when 

 disturbed, and can not be collected readily by ordinary methods. If 

 heat is being used as in the Berlese trap, great care should be taken 

 that the material does not catch fire. Your specimens may not only 

 he damaged in this way but you could also have no place to work 

 the next morning. 



COLLECTING APPARATUS 



1. Sweeping Net. — The sweeping net needs to be strong enough to 

 stand rough beating and sweeping. For the bag, 6-ounce drill, heavy 



Fig. 39. Sweeping net: a, net handle with metal cylinder to hold 

 the ring in place; b, ring; c, net handle with grooves; d, 

 bag. 



muslin or light canvas is usually recommended. The handle with a 

 length of three to four feet and a diameter about an inch is desirable. 



22 



