NO. II LARVAE OF THE ELATERID BEETLES GLEN 1 55 



2 prominent fine setae anteriorly and 2 smaller setae farther caudad ; 

 lateral margins slightly raised and carinate, typically with 5 promi- 

 nent, sharp, setiferous "teeth" (to), sometimes with smaller "teeth" 

 between larger ones, as many as 8 or 9 "teeth" on each side in some 

 specimens; transverse impression (trim) continues across segment. 

 Tergite continues uninterruptedly laterally and on posterior ventral 

 surface ; usually with from 20 to 35 setae on each side, many issuing 

 from small sclerotized tubercles ; anteriorly on lateral aspect with a 

 few pits. Distance between posterior margin of pleural area and 

 anterior margin of caudal notch approximates one-fourth total length 

 of segment (exclusive of urogomphi). Pleural area large, trans- 

 versely striate with small ovate sclerite near anterior ends. Sternum 

 of 2 sclerites, separated anteriorly by faint median suture and pos- 

 teriorly by tenth abdominal segment; each sclerite with from 5 to 10 

 setae, mostly in irregular row adjacent to tenth abdominal segment. 



Urogomphi (ur, fig. 29, b; fig. 29, c) separate, bifid; projecting 

 dorsocaudad ; prongs subequal in length, but differing in shape. Inner 

 prong (ipr) robust, subquadrate (rarely subtriangular), projecting 

 caudomediad ; anteromedial margin strongly sclerotized, dark ; with 

 I or 2 setiferous tubercles (tub) on caudolateral aspect, another seta 

 just ventrad to tubercles and usually a few minute setae scattered 

 over caudal aspect. Outer prong (opr) less robust, corniform, pro- 

 jecting caudad or dorsocaudad, sometimes slightly laterad; terminat- 

 ing in sharp horny point usually curving slightly forward or inward ; 

 with a prominent setiferous tubercle situated caudolaterally near 

 base of prong; i prominent seta on inner aspect, about halfway up 

 prong, I smaller seta on posteromedial surface and i minute seta 

 medially near base of prong. Undivided part of urogomphus short, 

 broad ; usually with i very short, fine seta near midventral aspect. 

 Caudal notch (cii) small, subcircular, almost closed by incurving 

 inner prongs. 



Tenth abdominal segment with whorl of 10 fine setae, sometimes a 

 few additional minute setae ; anal aperture linear and median. 



Material used in study. — Twenty-one larvae, all from Saskatoon, 

 Saskatchewan, were examined. This species has not been reared, 

 and identification is based upon field association of larvae and 

 adults. However, misidentification is unlikely because nearly all other 

 elaterid larval types occurring in fields at Saskatoon have been identi- 

 fied through rearing. The material examined is deposited in the 

 Canadian national collection. 



