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



1. A piece of finely drawn glass tubing furnished with clips held in place by 

 a small rubber band (fig. 12). 



2. A tin can or box to serve as an oven, and a spirit lamp or some other heating 

 unit. 



Place the larva on a clean blotter and force the body contents out 

 by gently rolling a piece of glass tubing or round pencil from just 

 back of the head to the end of the abdomen, being careful not to break 

 off spines and hairs. Insert the drawn end of the glass tubing into 

 the anal opening of the larva and secure it in place with the clips. 

 Blow gently into the glass tubing so that the larva is distended to 

 its normal size but not distorted, and bake it in the oven until dry, 

 blowing the specimen meanwhile so it does not collapse, and being 

 careful not to scorch it. When it is thoroughly dry, carefully remove 

 it from the glass tubing by means of a fine dissecting needle and 

 mount it on a twisted wire as shown in figure 11, E. This kind of 

 mounting is quite firm if the twisted wire extends inside the larva 

 for about two-thirds the length of the specimen. 



Figuee 12. — Tip of drawn glass tubing, showing clips holding larva in place for 



inflation. 



RIKER MOUNTS 



Occasionally it is desirable to arrange specimens for exhibition in 

 such a way that they may be freely handled without injury. This 

 may be done in various ways, but the method most frequently em- 

 ployed is to use the so-called Riker mount. This consists of a flat 

 cardboard box filled with cotton on which the unpinned specimens 

 are placed and covered with a glass top which holds them in place. 

 Eiker mounts may be purchased from most supply houses. 



SPREADING BOARDS AND BLOCKS 



The construction and use of the spreading board are illustrated in 

 figure 13. The active collector will find it advantageous to have sev- 

 eral boards with the middle grooves of different widths to accommo- 

 date insects of various sizes, but for general purposes a board made 

 from the following materials will be satisfactory : 



1. A hardwood base, % by 4 by 12 inches. 



2. Two hardwood endpieces, % by % by 4 inches. 



3. Two softwood toppieces, % by l 7 / 8 by 12 inches. 



4. One flat strip of cork, Vi by 1 by 11 inches. 



When assembled as illustrated, the softwood toppieces leave a groove 

 one-quarter inch wide. On the underside of these the cork strip is 

 glued so that it covers the space between the toppieces. 



Specimens must be thoroughly relaxed for spreading; otherwise 

 they will be broken. Figure 13 shows the wings on the left side of 

 the specimen spread in the proper manner. The first step in spread- 

 ing the wings, after pinning the specimen in the groove at the proper 

 height, is shown on the right side of the board in figure 13. To com- 



