ROSS: HOW TO COLLECT AND PRESERVE INSECTS 21 



(carbolic acid) and place over it a piece of cork, cardboard, or 

 wood cut to fit the jar. The lid must be practically airtight. 

 Place the dry specimens on the cork, cover tightly, and in a day 

 or two they will be soft and pliable enough for pinning or spread- 

 ing, the next steps toward permanent arrangement of the collec- 

 tion. 



The relaxer will "sweat" if kept in too hot a room, and will 

 spoil the specimens. Also, the insects will be spoiled if left in the 

 relaxer too long. The correct length of time varies with each 

 relaxer and can be learned only by experience. 



HOW TO MOUNT AND PRESERVE SPECIMENS 



Most adult insects in collections are mounted on pins. Such 

 insects as beetles, grasshoppers, butterflies, moths, flies, and 

 bees are pinned directly through the body from top to bottom. 

 Small insects, such as leafhoppers, plant bugs, small beetles, and 

 the like, are glued on card points. Immature insects and the adults 

 of some groups are best preserved in fluid. 



Preservation in Fluid 



Caterpillars and other immature stages of insects should be 

 preserved in fluid. Grain alcohol at 80 per cent or formaldehyde 

 at 4 per cent are suitable. Caterpillars, grubs, and maggots should 

 first be heated 5 or 10 minutes in water just at the boiling point. 

 This treatment sterilizes the specimens and prevents their dis- 

 coloration by bacteria in the digestive system. 



Many soft-bodied adult insects, including bristletails, spring- 

 tails, stoneflies, and caddisflies, also should be preserved in fluid. 

 If pinned they shrivel to such an extent that few identifying 

 characters can be seen. The preserving fluid in the vials in which 

 insects have been placed should be changed at the end of the first 

 day or two. 



Some hard-shelled insects may be preserved in fluid. Ants 

 and beetles may be thus treated temporarily and later they may 

 be pinned and dried. 



Preservation by Pinning 



Hard-bodied insects, such as beetles, flies, and wasps, are pre- 

 served as dry specimens on pins better than in fluid. The pinned 



