22 MISC. PUB. 601, U. S. DEPT. OF AGRICULTURE 



should be flat and smooth ; the groove may be of any desired width, 

 A hole should be drilled through the center of the block to permit 

 the insect pin or "minute nadel" to extend below the level of the 

 groove, and the bottom of the groove should be packed with cellu- 

 cotton or fitted with a strip of soft pith. When insects are mounted 

 on the spreading block, thin, flat, rectangular pieces of celluloid are 

 used to hold the wings in place. After the wings are properly ar- 

 ranged, each side of the block should be wrapped, but not too tightly, 

 with a piece of thread, as illustrated. The spreading of very small 

 insects is a task requiring considerable skill and patience. 



Specimens should be left on the spreading board or block until 

 thoroughly dry. For large insects this requires 2 or 3 weeks ; smaller 

 specimens will dry in less time. During this time they should be 

 stored in pestproof containers. Do not forget the collection-data label, 

 which should be asociated with the specimen at all times. 



RELAXING JARS 



Insects that have dried after being killed in the cyanide bottle must 

 be relaxed before they are mounted. This can easily be done in a 

 relaxing jar made as follows: Into a wide-mouth jar or can with a 

 tight cover put an inch or two of clean sand ; saturate the sand with 

 water to which a few drops of phenol (carbolic acid) have been added 

 to keep mold from growing; cover the sand with a piece or two of 

 cardboard cut to fit the jar, and it is ready for use. Specimens must 

 not come in direct contact with the water and should not be left in 

 the relaxer too long or they will be spoiled. From 1 to 3 days is usually 

 sufficient. A relaxer should not be left where it will get too warm, 

 or it will "sweat" on the inside. 



LABELING THE SPECIMENS 



During the course of preparation and mounting, specimens should 

 have associated with them a temporary label giving essential informa- 

 tion as to date and place of collection ; and before they are put away 

 in the collection they should be labeled with a permanent label, which 

 is either pinned below the specimen if the specimen is mounted, or 

 is placed in the vial if the specimen is preserved in liquid. These 

 labels are usually small, and for that reason the data that can be given 

 must be restricted to the most important information. Any additional 

 information about the specimen or specimens should be kept in field 

 notes, which can be associated with the proper material by means of lot 

 numbers or some other convenient system. When specimens are sent 

 for identification they should always be accompanied by all available 

 information. 



WHAT INFORMATION IS ESSENTIAL 



The following information should be given on the label or labels 

 for each specimen : 



1. Locality : The place of collection should be given as exactly as possible and 

 should be so designated that it can be found on a good map. If the place of 

 collection does not appear on a map, it may be given in terms of the approximate 

 direction and distance from some landmark or town. 



