HOW TO KNOW THE IMMATURE INSECTS 



tant that the specimens be kept in as good condition as possible. The 

 insect body should retain its correct shape and the colors should like- 

 wise be kept as true to life as possible. No one method is entirely sat- 

 isfactory to cover all these aspects. 



Immature insects are not ordinarily mounted on pins, but 70% to 

 80% alchohol or other special liquid preservatives are used. Occasion- 

 ally the small-bodied specimens need to be mounted on slides for mic- 

 roscopic study. Before the insect is placed in the preservative it should 

 be killed by putting it into boiling water for one to five minutes. The 

 length of time in boiUng water depends entirely upon the size of the 

 specimen. It will be sufficient when the specimen become swollen up. 

 This method of fixing is found even better than by injecting the pre- 

 servative into the insect body. 



For exhibition purposes, the larvae are often inflated and kept in 

 dry condition. However, that is not desirable for scientific study, for 



during the process of inflation, many 

 I cuticular appendages could be damag- 

 j ed and the body color is sometimes 

 (h^^^^r~''i~^~y'Tfr^^^^^ changed. Inflating larvae is rather 



^^""^"-^-■'—^-uKAz^^x^-^-'^'^^ simple; place the larva on a clean blot- 

 ter or a piece of paper and press the 

 body contents out by gently rolling a 

 round pencil from just back of the head 

 to the end of the abdomen. 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 



Fig. 44. An infigted and into the glass tubing so that the larva 



mounted larva. . ,. . , , . ^ 



IS distended to its normal size but not 



distorted, and warm it gently in an oven until dry. A lamp can be 

 used for heating and a chimney or a tin can can be used as an oven. 

 For blowing air into the body, it is better to use a hand bellows. An 

 expansion bulb js desirable to give an even flow of air. When the 

 specimen is thoroughly dry, remove it from the glass tubing and mount 

 it on a kitchen match by inserting the match stem into the anal open- 

 ing and then mount the match stem on a pin (see Fig. 44). If the speci- 

 men i.*? too loose on the match stem, glue may be added. 



Specimens must always be accompanied by labels in which briel 

 information of date, locality and collector are recorded. For the liquid 

 preserved specimens, the label should be written with India ink or 

 black pencil and the label put in the preservative with the specimen. 

 For the pinned specimens, the label should be pinned below the speci 

 man. 



Peterson recommends the following preservatives: 

 1. X.A. mixture: 



Xylene 1 part. 



95% ethyl alcohol 1 part. 



Good for caterpillars, coleopterous larvae and Tenthredinid larvae. 



25 



