1 86 THE STUDY OF INSECTS 



wards the tip ; but in most cases the extreme tip is pointed and recurved, 

 forming a hook. The abdomen is usually stout, resembling that of a 

 moth rather than that of a butterfly. 



CLASSIFICATION OF THE LEPIDOPTERA 



The first step to be taken in the study of the classification of these 

 insects is to become thoroughly familiar with the nomenclature of the 

 wing veins; this is given on pages 32 to 33. It is a good plan to take 

 several of the larger moths and butterflies and make drawings showing 

 the courses of the veins of the wings in each, carefully indicating the 

 names of the veins on the drawings. 



As the scales on the lower surface of the wings are more closely ap- 

 plied to the wings than are those on the upper surface, the veins can be 

 best seen when the wings are examined from below. The veins can be 

 rendered more distinct for a few seconds by putting a little 95 % al- 

 cohol or benzol on the part of the wing to be examined; this can be 

 easily done by means of a camel's-hair brush. 



Sometimes it is necessary to remove the scales from a small part of 

 the wing in order to determine the nature of some characteristic; this 

 can be easily done by scratching them off lightly with a pin on the under- 

 side only. 



The above methods are all that are needed in the majority of cases 

 where the mere determination of an insect is the object. But when a 

 very careful study of the venation of a wing is to be made, it should be 

 bleached and mounted on a card or on a glass slip in order that it may 

 be studied with a compound microscope. The following is the method of 

 bleaching wings : — 



1. Remove the wings carefully so as not to break the frenulum if 

 there be one. 



2. Dip the wings in alcohol in order to wet them. 



3. Immersion for an instant in hydrochloric acid, one part acid to 

 nine parts water, will help but usually not necessary, 



4. Put them in Labaraque solution and leave there till the color has 

 been removed from the scales. If a wing bleaches slowly, the process 

 can be hastened by dipping it in the dilute acid and returning it to the 

 Labaraque solution from time to time. This solution can be procured of 

 most druggists. It deteriorates if left exposed in strong light. If it can- 

 not be obtained, use an aqueous solution of chloride of lime. 



5. When a wing is bleached put it in alcohol and leave it there three 

 to five minutes. This is to wash off the Labaraque solution. The wing 

 can then be mounted on a card. But it is better to mount it as described 

 below. 



6. Put wing on slide in alcohol, blot off excess alcohol, add a drop or 

 two of oil of lavendar, let stand several minutes, put on balsam and 

 cover with thin glass. 



Wings bleached and mounted in this way make an important addition 

 to a collection. The slides should be carefully labelled to correspond with 

 the rest. 



There are a few special terms used in describing the wings of the 

 Lepidoptera which should be learned : — 



Frenulum. — In most moths there is a strong spine or a bunch of 



