NO. II LARVAE OF THE ELATERID BEETLES GLEN '^'J 



Description of "mature" larva. — Length 13 mm., fully distended; 

 greatest breadth 1.4 mm. on fifth and sixth abdominal segments. 

 Largest larva examined was 14 mm. long and 1.9 mm. wide. Body- 

 robust, with large membranes on lateral aspect ; all segments broader 

 than long ; head and ninth abdominal segment about two-thirds great- 

 est body width. Dorsum light brown or yellow brown (near "ochra- 

 ceous tawny," Ridgway, 1912) ; head, prothorax, and urogomphi usu- 

 ally slightly darker; venter paler. Dorsum slightly rugose; with 

 small shallow pits, rather inconspicuous. 



Head subquadrangular with subparallel sides (very slightly arcu- 

 ate) ; flattened above and below. 



Frontoclypeal region with posterior part extending backward al- 

 most to foramen magnum, bluntly rounded posteriorly. Two promi- 

 nent anterior nasosulcal setae on each side of base of nasale. Nasale 

 (fig. 18, a), unidentate, terminating sharply when uneroded. Sub- 

 nasale (fig. 18, a) consisting of strongly sclerotized transverse ridge, 

 slightly convex anteriorly; serrate when uneroded, with approxi- 

 mately 15 subequal, short, sharp, forward-projecting denticles (fewer 

 in smaller specimens). Paranasal lobes produced beyond nasale, each 

 bearing 3 setae (i small). 



Epicranial plates finely punctulate. Dorsal sulci shallow, each with 

 4 setae subequally spaced, the most anterior seta very long, others 

 small. Ventral sulci bearing row of 5 to 7 setae, usually 2 to 4 con- 

 spicuous. On each gena, usually 3 lateroepicranial setae, 2 large with 

 I smaller seta between; sometimes with i very small seta ventro- 

 cephalad to the more ventral of the 2 large hairs; i well-developed 

 seta slightly laterad of anterior half of dorsal sulcus. Eye spot black, 

 well defined, ovate or circular; surrounded by 5 unpaired setae, 3 

 well developed, 2 small. Postgenal areas expanded mesad, but well 

 separated; glabrous. 



Gula short, moderately wide ; glabrous. 



Antenna (fig. 18, d) with first segment weakly clavate, at least 

 three-fourths as wide as long ; without setae ; 3 to 5 small pores. Sec- 

 ond segment subcylindrical, as wide as long; one-half length of basal 

 joint; I or 2 pores; a few minute setae or pegs borne distally; i 

 medium-sized conical "sensory" appendix (sap) just ventrad to base 

 of third segment and i smaller appendix farther ventrolaterad ; in a 

 few specimens there were 2 smaller appendices, making a total of 3 

 appendices on i antenna, and in 2 specimens the small appendix was 

 lacking on i antenna but present on the other. Terminal segment as 

 long as second joint, but only one-quarter as wide ; 3 or 4 setae on 

 apex. 



