NO. II LARVAE OF THE ELATERID BEETLES GLEN II 



hours, then thoroughly rinsed in water and put in 95-percent alcohol 

 for several minutes before mounting in Canada balsam. 



The study of the mandibles was facilitated, in many instances, by 

 fastening each one with seccotine to the tip of a minuten pin, the base 

 of which had been thrust into the small end of a cork. By inserting 

 the cork into a vial the mandible could be stored safely. Mounts of 

 this type were particularly useful in observing sculpture, of which 

 only a limited view could be had from slides. 



KOH was used to distend dry, hard, shriveled larvae and to soften 

 larval exuviae so they could be made ready for examination. Ethyl 

 acetate was also used for softening larval skins. One or two drops of 

 ethyl acetate in a concave-bottomed dish was found helpful in manipu- 

 lating small sections of exuviae under the binocular. 



EXAMINATION OF MATERIAL 



The material was examined by two distinct methods : first, a pre- 

 liminary survey to determine the general relationships of the s])ecies 

 that had been assembled, and second, a detailed study to obtain sepa- 

 rating characters for closely related groups and species. 



The Reconnaissance Survey 

 When the great bulk of the material had been assembled and the 

 preparation of slides was well advanced, a comprehensive morphologi- 

 cal survey was undertaken. This included all available species of the 

 tribe Lepturoidini. By the method of comparative morphology a care- 

 ful examination was made of the mandibles, nasale, subnasale, frons, 

 paranasal lobes, gula, prosternum, number of spinelike setae on the 

 episterna of the mesothorax and metathorax, setal pattern on abdomi- 

 nal mediotergites, "impressions" and other sculpturing of abdominal 

 mediotergites, general type of pleural and sternal structures, and the 

 ninth and tenth abdominal segments. Each structure was examined 

 independently in all species before examination of the next struc- 

 ture was begun. Throughout this survey descriptive notes were made, 

 numerical data tabulated, and numerous careful preliminary drawings 

 prepared. At this time one specimen of each species was examined, 

 rarely more. Some attempt was made to group the species on the 

 basis of each of the above characters, and a preliminary arrange- 

 ment of "species groups" was deduced from the entire evidence. 



The Detailed Study 



The detailed examination of Litdiiis was begun by preparing a com- 

 prehensive illustrated description of Ludhis aeripennis destructor 



2 



