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ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 39 



specimens are more convenient to study and they retain their 

 natural coloring better. Flies and butterflies are covered with 

 hairs or scales that clot or break off if the specimens are bottled, 

 and for this reason they should be pinned. 



Common household pins are too thick and short for pinning 

 insects. Longer, slender pins, called insect pins, are necessary and 

 may be purchased from various supply houses. They should be of 

 spring steel; a brass pin will corrode and be destroyed by acids 

 in the insect's body. The pins are obtained in numbered sizes, of 

 which 1, 2, 3, and 4 will be found of most general use, and sizes 

 or 00 of advantage in special cases. 



Medium to Large Insects. — Medium to large hard-shelled 

 insects, such as moths, beetles, flies, bees, and wasps, should be 

 pinned vertically through the body, fig. 11a. It is essential that 

 the pin pass through a fairly solid part of the body, and to insure 

 this the following standard procedures should be adopted. 



Fig. 11. — Pinning. Medium- to hard-shelled insects are mounted by being 

 pinned through the body in the manner shown at a. The black spots show 

 the location of the pin in the case of bees, flies, and wasps, 6; stink bugs, c; 

 grasshoppers, d; and beetles, e. 



