COLLECTION AND PRESERVATION OF INSECTS 13 



to absorb waste that accumulates and which might otherwise cling 

 to the specimens. 



Ether has the disadvantage of being highly inflammable and must 

 be used with great care. Other solvents which may be used are chloro- 

 form, benzene, xylene, and diethyl carbonate. If chloroform is used, 

 the specimens must be held submerged by a wire screen. After being 

 degreased, specimens should be transferred to a clean pad of absorbent 

 tissue and their appendages arranged ; after they are sufficiently dry 

 they may be mounted. 



Specimens that contain but little fatty tissue (lipoids), and hence 

 do not ordinarily become greasy, may be killed in the cyanide jar 

 or the ethyl acetate killing bottle and mounted without further prep- 

 aration. Pinned specimens that have become greasy owing to the 

 decomposition of body fats may be degreased by being put in an ether 

 or chloroform bath for a few hours. Other killing agents, such as 

 carbon tetrachloride, ether, chloroform, and benzene may be used, but 

 each has some objectionable features, and they are not recommended 

 for general use. 



Some insects, such as scale insects, aphids, lice, thrips, and other 

 minute forms, can be satisfactorily studied only after they are mounted 

 on a microscope slide. These insects should be killed and preserved 

 according to the instructions which follow, but the proper preparation 

 of slide mounts is a task requiring considerable equipment and experi- 

 ence, and slide preparations should not be attempted without the aid 

 of specific instructions, which are usually different for different groups 

 of insects. 



The following outline gives instructions for killing and preserving 

 the commoner types of insects and also indicates the usual method of 

 mounting for study. Methods of mounting specimens on pins are 

 discussed in detail later in this bulletin. The steps between killing 

 and mounting specimens killed in alcohol or the ethyl acetate killing 

 jar have been outlined above and are not repeated here. Descriptions 

 and illustrations of common representatives of most of these insect 

 groups are given under Eecognition of Material, page 26. 



Anoplnra (sucking lice) : Kill and preserve in alcohol ; mount on slides. 



Coleoptera (beetles) : Kill in alcohol or ethyl acetate vapor ; mount on pins. 



Collembola (springtails) : Kill and preserve in alcohol; mount on slides. 



Corrodentia (booklice) : Kill and preserve in alcohol. 



Dermaptera (earwigs) : Kill in cyanide, ethyl acetate vapor, or alcohol ; mount 

 on pins. 



Diptera (flies) : Kill in cyanide, except minute forms, such as eye gnats and 

 fungus gnats, which should be killed in alcohol ; mount on pins. 



Ephemeroptera (Mayflies) : Kill and preserve in alcohol. 



Hemiptera (true bugs and their allies) : Kill in cyanide, ethyl acetate vapor, 

 or alcohol, except the immature stages, aphids, scale insects, and Aleyrodidae 

 (whiteflies) ; mount on pins. Nymphs should be killed in alcohol and mounted 

 on pins. Aphids should be killed in alcohol and mounted on slides. Scale insects 

 and whiteflies on host material should be preserved dry, but if they are not on 

 host material they should be preserved in alcohol ; mount on slides. 



Hymenoptera (bees, wasps, ants, etc.) : Kill in cyanide, except ants, gall wasps, 

 and small parasitic forms, which should be killed in alcohol; mount on pins. 



Isoptera (termites) : Kill and preserve in alcohol. 



Lepidoptera (moths and butterflies) : Kill in cyanide; mount on pins. 



Mallophaga (biting lice) : Kill in alcohol ; mount on slides. 



