10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. Ill 



PRESERVATION AND STORAGE OF MATERIAL 



When only one or two larvae of an unreared type were collected, 

 none was preserved until after some attempt had been made to rear 

 them, but care was taken to preserve immediately any specimens that 

 died. When more than two larvae of the same type were collected, 

 some were preserved at once for morphological purposes, at least one 

 large specimen being included if there were several available. 



Several different preservatives were used, but 70 percent ethyl 

 alcohol was found to be satisfactory. Preservatives containing acetic 

 acid distended the larvae and made them more suitable for morpho- 

 logical study, but the acid tended to destroy the muscles after the 

 material had been preserved for a year or more. 



Larvae and the exuviae of reared specimens were placed in small 

 shell vials which were plugged with cotton batting and stored in pint 

 fruit jars. Each vial contained a place-date-collector label and the 

 record number of the specimen. The latter permitted cross reference 

 to collecting notes and, in the case of reared specimens, insured 

 accurate association with adults. The exuvium of a reared specimen 

 was always kept in a separate vial and the date of emergence of its 

 adult was recorded on the date label. Preservative was added both 

 to the vials and fruit jars, thus giving double protection against 

 desiccation. 



Reared adults were pinned and labeled with exactly the same infor- 

 mation as was given on the labels with their exuviae. All such adults 

 were stored in a special collection and were not incorporated into 

 the working collection of the laboratory. 



PREPARATION OF MATERIAL FOR EXAMINATION 



The general procedure followed in the preparation of the material 

 of each species was to mount on slides the head parts of one or more 

 specimens, then to soak the remainder of the specimen in lo-percent 

 KOH until all muscles and viscera could be squeezed out and the 

 specimen fully distended to reveal the sclerites of the thorax and 

 abdomen. Such specimens were then returned to alcohol and used to 

 supplement observations made upon entire larvae. Specimens for 

 dissection were carefully selected to avoid badly eroded mouthparts. 

 In many instances, parts of the thorax and abdomen were placed upon 

 slides, and for Ludins aeripennis destructor the head parts of many 

 specimens were dissected and all parts of at least one larva were 

 mounted. Dissected parts were placed in lo-percent KOH for a few 



