4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO3 



fluid ceases to grow yellow owing to dissolved oils, one or two changes 

 of the bath aiding the process when the bulk of material is great.- 

 The duration of treatment varies from about 12 hours to a week, 

 depending upon the size and number of specimens per bottle, the 

 volume of ether in proportion to material, and the fat content of 

 the particular insects being degreased. To protect the specimens from 

 the clinging, watery exudate which escapes from them and tends to 

 work its way to the bottom of the container, a small wad of loosely 

 folded aljsorbent tissue or filter paper should first be placed in the 

 bottle. This will serve to capture such waste. 



Ether will preserve ethyl acetate-killed material in a perfectly re- 

 laxed condition for an indefinite period. However, a certain degree 

 of surface etching will take place in very oily ether where specimens 

 should never be left very long. Also, very small specimens isolated 

 in a volume of ether too large to be discolored by them may become 

 temporarily brittle if given this treatment for more than a few hours. 

 Should such an event occur, a drop of Barber's fluid (XI) on the 

 dry insect will serve to free its articulations instantly. 



Bulky s})ccimens wliich have swelled in the ether bath should be 

 removed to a pad of absorbent paper where all turgidity can be elimi- 

 nated by gentle pressure after pricking through the dorsal abdominal 

 and nuchal membranes with a needle. Such material should always be 

 returned to clean ether for further degreasing before mounting. 



Very hairy insects - and those possessing easily detached scales or 

 farinose areas should be subjected to the ether bath only when the 

 oily nature of the species at hand demands such treatment. Rela- 

 tively few Coleoptera (certain groups of farinigerous Buprestidae. 

 Curculionidae, etc.) fall under this category. These cannot be ether- 

 treated for long without the loss of at least some of their powdery 

 secretion. 



- Degreasing of pilose insects, such as some bees, flies, etc., must be tliorougb 

 if attempted at all. When body fats have been completely removed, the pile 

 may rather easily be restored to its natural fluffiness by lifting it with a 

 camel's-hair brush while applying a stream of air througli a blowpipe. The 

 detachable pile which covers the bodies of moths cannot, of course, withstand 

 rubbing or brushing. Gravid females of large-bodied species, however, often 

 require degreasing because of the high lipoid content of their egg masses ; 

 since immersion is to be avoided in such cases, it is therefore desirable, before 

 spreading these, to remove the viscera through an incision in the ventral 

 abdominal wall. By clamping the pin (head end) in a horizontal ix)sition, it is 

 possible to perform this operation with the abdomen hanging free. The ab- 

 dominal cavity should be dusted with cotton dipped in dry plaster, blown 

 clean, and loosely stuffed with fresh cotton. 



