COLLECTION AND PRESERVATION OF INSECTS 



15 



Figuee 5. — Method of folding a rectangular piece of paper to form a triangular 

 envelope for large-winged insects : A, Correct shape of unfolded paper, showing 

 where the folds should be made and the sequence of the first three folds ; 

 B, "triangle" almost completely folded, showing correct position of the enclosed 

 butterfly. 



developed standard pinning practices, designed to avoid injury to 

 the specimens and to expedite study. Although methods of preparing 

 specimens are constantly being improved, currently accepted prac- 

 tices should be observed in the interest of uniformity until the superi- 

 ority of other methods has been clearly demonstrated. 



DIRECT PINNING 



Ordinary household pins are too short and thick and should not 

 be used for pinning insects. Insect pins, which may be purchased 

 from supply houses, should be of good-quality spring steel and thor- 

 oughly japanned so as to be nearly rustproof. They may be obtained 

 in numbered sizes and different lengths suitable for pinning insects 

 of various sizes. For most purposes No. 2 or No. 3 pins 34 mm. long 

 will be found satisfactory, although a smaller size, No. 1, may occa- 

 sionally be desirable for small flies, and larger and longer pins, such 

 as No. 4 or No. 5 pins 37 or 39 mm. long, are better for large-bodied 

 moths, beetles, and cicadas. A comparison of a millimeter scale with 

 the more familiar inch scale is given in figure 6. 



m.m. 10 



20 30 40 50 60 70 



liuLliiiIiiiiI 



imiiiiiliiiiliiiilimlmiliiiiliiiiliiiiliiiilimliiiili 





lllllll 



,ll,l 





,:,, 



l|l|l|l|l|l|l|l 



INCHES 



12 3 



Figure 6. 



-Comparison of inch and millimeter scales. A centimeter equals 

 10 millimeters. 



Medium-sized and large insects should be pinned vertically through 

 the body with a pin of appropriate size. Figures 7 and 8 illustrate 

 some right and wrong pinning practices. Before pinning a specimen 

 it is well to examine "the under side so as to be sure that the pin will 

 not break off a leg where it comes through. The standard methods 

 for pinning the commoner types of insects are as follows : 



