NO. II LARVAE OF THE ELATERID , BEETLES GLEN 163 



tridentate. Frontoclypeal area truncate posteriorly. Three latero- 

 epicranial setae on each gena, arranged as a dorsal pair and i unpaired 

 hair farther ventrad. Mandibles robust. Without setae on ventral 

 surface of basal segment of labial palpus. With i to 4 setae (rarely 

 spinelike) on each episternum of mesothorax and metathorax. 

 Abdominal mediotergites with impressions not extending to middorsal 

 suture ; and bearing sparse, small punctures. 



Specimens examined are deposited in the Canadian national col- 

 lection. 



LIMONIUS AEGER LeConte 

 Figures ii, d; 31, d 



According to \'an Dyke (1932, p. 339) this species occurs from 

 Nova Scotia and the New England States west to British Columbia 

 and south through the Rocky Alountains to New Mexico and from 

 the Cascade Mountains to Mount Hood, Oreg. Larvae have been 

 reared from Saskatoon, Saskatchewan. 



Under Saskatchewan conditions this species is found in forest litter 

 and in the superficial layers of soil under the litter. The larvae have 

 been collected in greatest abundance under mixed shrubs and poplar 

 along the banks of the Saskatchewan River. In the muck soils of 

 southern Quebec and Ontario, larvae believed to be of this species are 

 injurious to vegetables. Rearing records indicate that pupation nor- 

 mally occurs in soil or litter from late July to early August. 



The larva of aeger belongs to that group of Limonius that have 

 very small outer urogomphal prongs {opr, fig. 31, rf). It shows super- 

 ficial resemblance to the larva provisionally regarded as confusus 

 LeConte, but differs as follows : Eyes absent ; ninth abdominal seg- 

 ment without mediodorsal groove (sometimes with a shallow subcircu- 

 lar depression bearing short, paired paramedian grooves), and with a 

 sinuate "impression" laterally near base of segment ; prominent setae 

 paired on mediotergites of abdominal segments ; each paranasal lobe 

 bearing a cluster of 12 or more "sensory" pores ; and usually 4 to 7 

 spinelike setae on each episternum of mesothorax and metathorax. 



The largest larvae attain 12 mm. in length. Ninth abdominal seg- 

 ment without setae on central dorsal area, small and much-rounded 

 "teeth" on lateral aspect of dorsum, and distance between caudal notch 

 and pleural area approximating one-fifth to one-fourth length of seg- 

 ment, exclusive of urogomphi. Nasale with tip tridentate. Subnasale 

 of many fine teeth. Frontoclypeal area truncate posteriorly. Two 

 prominent unpaired lateroepicranial setae on each gena. Abdominal 



