COLLECTION AND PRESERVATION OF INSECTS 5 



Although the beating net may be used on thorny bushes and trees, 

 most other nets tear easily and should be used with care. Insects 

 should be removed from the beating net after a few sweeps so that 

 they will not be battered by the debris that accumulates in the net. 

 Lively insects, such as leafhoppers, can be easily removed from the 

 beating net with an aspirator. (See p. 7.) To do this, stand so that 

 the open end of the net is not directly toward the sun, rest the loop 

 of the net on your head, and, if possible, let the bag of the net be 

 distended by the wind. Thus one hand is free to manipulate the bag 

 and the other to handle the aspirator, while the head and arm of the 

 collector fill the opening of the net sufficiently to prevent the escape 

 of most specimens. 



In using the fly net or butterfly net, after the captured specimen 

 has been enclosed in the tip of the net by grasping the bag with one 

 hand a little from the end, insert the open killing bottle into the net 

 and permit the specimen to drop into it. While the bottle is still 

 in the net, cover the opening until the specimen becomes stupefied; 

 otherwise it may escape before the bottle can be removed from the 

 net and closed. 



KILLING BOTTLES 

 Construction 



Any fairly heavy glass jar or vial with a wide mouth is satisfactory 

 for a killing bottle, and every collector should have several bottles 

 of various sizes. Empty pickle jars, olive jars, and the like will fur- 

 nish a considerable assortment of larger bottles, and smaller ones 

 may be made from test tubes or shell vials 1 to iy 2 inches in diameter. 

 These should be supplied with tight-fitting corks or screw caps. A and 

 B of figure 2 illustrate two bottles of convenient shape. Figure 2, (7, 

 illustrates a convenient adaptation of a screw cap for a jar to keep 

 bees, grasshoppers, and other lively insects from escaping from the 

 killing bottle when it is opened for putting in other specimens. This 

 cap is made by soldering an incomplete metal cone to a screw cap 

 with the top cut out. A metal tube % to 1 inch in diameter is then 

 soldered inside the cone. 



Chemicals 



Various chemicals may be used in the bottles for killing agents ; two 

 of the best are discussed below. 



Cyanide. — Calcium cyanide, potassium cyanide, or sodium cyanide 

 may be used. Wrap some granular cyanide (a heaping teaspoonful 

 for small bottles, larger amounts for large bottles) in cellucotton, 

 or place it in a "nest" in cellucotton or a little cloth bag, and put this 

 in the bottom of the bottle. Over this place a plug or several layers of 

 cellucotton or a layer of dry sawdust. Cellucotton is inexpensive and 

 may be purchased at most large drug stores or from supply houses. 

 If the bottle is more than V/ 2 inches in diameter, a 14-inch layer of 

 plaster of paris should be poured in and allowed to harden for a few 

 hours before the bottle is corked. If the bottle is a small one, several 

 disks of clean blotting paper, cut to fit the bottle snugly, may be used 

 in place of the plaster of paris. 



