ROSS: HOW TO COLLECT AND PRESERVE INSECTS 13 



Many insects feign death when they drop and they are difficult 

 to see until they "revive" and start to move away. 



In late fall and winter, sifting is one of the most profitable 

 types of collecting; in any season, it will turn up such things as 

 rare spiders and beetles. It is more successful for large, active 

 insects than for small, slow-moving forms, which are better 

 secured with Berlese funnels. 



Berlese Funnel 



When you are wandering through woods or fields, do you 

 realize that you are stepping on more insects than you ever see? 

 The ground cover and soil are peopled by a vast assemblage of 

 little animals that are seldom seen by the casual collector. Be- 

 cause many of these animals are exceedingly minute, they are 

 difficult to see and collect by ordinary methods. 



The most efficient method for collecting this fauna is by the 

 use of Berlese funnels, named after the Italian entomologist Ber- 

 lese (pronounced Bur-lazy), who first used them extensively. A 

 Berlese funnel is a very simple apparatus, consisting of a fairly 

 long funnel, suspended wide end up, with a screen placed about 

 a third of the way down the funnel ; heat is applied either around 

 the upper portion or over the top of the funnel, and a container 

 of preservative, preferably 80 per cent ethyl alcohol, is placed at 

 the small bottom opening. Leaf mold or other material is placed 

 on the screen, the heat source is turned on, and soon the animals 

 begin to leave the drying sample and migrate downward, dropping 

 into the preservative. 



Fig. 7 illustrates a funnel that has proved very satisfactory ; 

 it is 15 inches from top to bottom, and the top has a diameter of 

 12 inches. The bottom opening, exactly seven-eighths inch in 

 diameter, fits into the mouth of a half -pint cream bottle, which 

 makes an ideal container for the preservative. Three angled 

 brackets or hangers are soldered inside the funnel to provide a 

 rest for the screen, which is made of quarter-inch or eighth-inch 

 mesh hardware cloth; the mesh used depends upon the type of 

 sample. A battery of several funnels in a rack, fig. 8, will allow 

 the collector to sample several kinds of material at the same time. 



If steam is used as a source of heat, the small copper lines 

 that conduct it act as a partial support for the funnel by encir- 

 cling it about halfway between the screen and the top ; a piece of 

 cloth is tied tightly over the top of the funnel to prevent the 



