COLLECTING AND PRESERVING INSECTS BANKS. 



69 



PREPARATION OF LA RATE. 



A method of preserving caterpillars by inflation has long been used 

 by lepidopterists. The larva? should be killed in a cyanide bottle or 

 in alcohol. Cyanide is generally considered the best for most larvae. 

 The caterpillar is placed on a piece of blotting paper, a pencil is 

 rolled over the larva from the head to the tip of the body, thus pro- 

 truding the tip of the alimentary canal. This is snipped off by a 

 pair of scissors or a sharp knife, and then by rolling a pencil, as before, 

 a number of times over the larva the contents are squeezed out of 

 its body. One should be careful to do it rather slowly, at least with 

 delicate larvae, so that the skin is not broken, for if rubbed too hard 

 or too long the pigment may 

 be removed from the skin. 

 The caterpillar should be 

 moved about on the blotting 

 paper during the operation, 

 so that it is not soiled by its 

 own juices. 



A glass tube with its tip 

 drawn out to a fine point is 

 then inserted into the anal 

 opening. The skin may be 

 fastened on the slender point 

 by a bit of thread or a drop 

 of glue. If the glass tip fits 

 rather tightly into the aper- 

 ture, then the skin may be 

 placed a moment in the oven 

 and then withdrawn. This 

 will stick the skin to the end 

 of the glass. A spring or 

 clasp of steel may be so ar- 

 ranged as to hold the larva 

 to the tube, or the skin may be held to the glass tube by a common 

 insect pin bent around the tube and then forward, with the tip 

 recurved (fig. 115). One may inflate the skin by blowing in the 

 tube; but a more effective way is to have a rubber tube on which is 

 a large rubber pneumatic bag and a smaller inflating bag at the end. 

 By squeezing the inflating bag the larger bag becomes inflated, and 

 this makes a steady pressure upon the larval skin. This operation 

 of inflating the larva should be performed over a small tin oven, as 

 shown in figure 114. The glass tube with attached larva is inserted 

 through the hole "d." If one expects to inflate many Larvae, an 

 apparatus of this sort will be very useful. But if only a few, or, for 



Fig. 114.— A drying oven for the inflation of lakv.i:. 



