COLLECTION AND PRESERVATION OF INSECTS 9 



the corners to a frame made by crossing and fastening together two 

 pieces of light wood, one of which should project a little beyond the 

 corner of the cloth to serve as a handle. The umbrella is used in- 

 verted and should have the handle jointed so that the umbrella may 

 easily be held upside down below branches and bushes. When in 

 use, both the beating cloth and the umbrella are held below the vege- 

 tation while the branches are struck sharply with a club. In this way 

 many insects will be jarred onto the cloth and can be readily captured. 

 These pieces of equipment are also handy when pulling bark from 

 trees and, when so used, will catch many specimens that would other- 

 wise escape. 



SIFTERS 



Many insects spend all or part of their lives in ground litter and 

 leafmold. These cannot be captured by ordinary collecting methods, 

 and because they are too active to be caught by hand, or they feign 

 death when disturbed, a sifter should be used. 



Almost any container with a wire-mesh bottom will serve as a 

 sifter. The size of the meshes in the screen will depend upon the size 

 of the insects sought ; for general purposes a screen with eight meshes 

 to the inch will be satisfactor}^. The screen may be fastened to a 

 wooden frame to make a box-shaped sifter, or it may be attached to 

 a wire hoop, which is then sewed to one end of a cloth sleeve about 

 12 inches in diameter. In the latter type of sifter it is convenient 

 to have a wire hoop of the same size at the other end of the cloth sleeve 

 to hold it open. 



Place the leafmold or ground litter in the sifter and shake it gently 

 over a piece of white oilcloth spread flat on the ground. As the insects 

 fall onto the cloth they may be easily captured with an aspirator or 

 tweezers. Many insects feign death and are not easily seen until they 

 move, so the debris on the cloth should not be discarded too quickly. 

 The sifter is especially useful for winter collecting. 



SEPARATORS 



The collector who wishes to obtain large numbers of the small 

 insects that are usually found in ground litter will find it advan- 

 tageous to construct a separator (usually called a Berlese funnel by 

 entomologists) for use instead of the sifter. Fundamentally, the 

 separator consists of a funnel over which a sieve containing leafmold 

 or other litter may be placed. The funnel leads into a receptacle 

 containing a liquid preservative, into which the insects fall when 

 driven from the material in the sieve by the progressive drying with 

 a light bulb or some other source of mild heat. Many separators, 

 some very elaborate, have been devised by entomologists, but all rely 

 on the same basic principles. Details of construction may be obtained 

 by writing to some entomological institution. 



COLLECTING AT LIGHTS 



Collecting at lights, especially on warm, humid nights, frequently 

 permits the collector to obtain in abundance insects that are captured 

 rarely or not at all by other methods. While light traps, many types 

 of which have been devised, are of use to entomologists for making 



