PRESERVING AND STUDYING INSECTS 



345 



May-flies, dragon -flies, and stone-flies. The pin is inserted in 

 the metathorax, and a fine wire run from the end of the body 

 into the thorax. In the case of the May-flies this wire should be 

 left projecting to serve as a support for the posterior setae, which 

 should be attached to the wire. The wings of both the May-flies 

 and dragon-flies should be spread. This is done by means of a 

 spreading board. 



Spreading boards. Fig. 480 shows the construction of a simple 

 spreading board. Two soft-pine boards are placed parallel on short 

 crosspieces, the boards being 

 at a slight angle to each other. 

 The edges of the board should 

 be from one sixteenth to one 

 half an inch apart, depending 

 on the size of the insects to be 

 mounted. A thin sheet of cork 

 is glued to the underside of 

 the boards. When the spread- 

 ing board is used, the insect 

 is pinned in the ordinary man- 

 ner and the pin is then forced 

 through the sheet of cork until 

 the dorsal portion of the insect 

 is nearly level with the upper 

 surface of the boards. The 

 spreading board, of course, 

 must be selected with a groove 

 wide enough to accommodate the body of the insect. After being 

 placed on the spreading board, the wings of the insect are brought 

 forward and held in position by narrow strips of paper or tracing 

 cloth, as shown in the illustration. Glass-headed pins are handy 

 for pinning the strips. The spreading board is then set away until 

 the insect is thoroughly dry. 



In the case of the May-flies the front margins of the first pair of 

 wings are brought forward until they are at right angles with the 

 body. In the case of the dragon-flies the hind margins of the first 

 pair of wings should be at right angles to the body. In pinning 

 stone-flies, usually only the wings of the right side are spread, 



FlG. 480. Board showing method of 

 spreading Lepidoptera. (Reduced) 



