NO. II LARVAE OF THE ELATERID BEETLES GLEN II7 



socket on caudolateral aspect of base of prong ; 3 or 4 short, fine setae 

 (sometimes minute) scattered over prong, sometimes additional fine 

 setae ventrally or laterally at base of prong. Undivided part of 

 urogomphus with i large seta ventrally just anterad to bases of 

 prongs. Caudal notch (en) moderately large, U-shaped, usually 

 slightly longer than wide; sometimes slightly narrowed posteriorly 

 by tips of inner prongs. 



Tenth abdominal segment with irregular whorl of about 20 fine 

 setae sometimes arranged in 2 whorls each of about 10 setae ; anal 

 aperture linear and median. 



Material used in study. — Three examples were examined, includ- 

 ing the larval exuvium of one specimen found as an adult in its 

 pupal cell. The adult was identified by W. J. Brown, of Ottawa. 



3; Waskesiu Lake, Saskatchewan; Aug. 10, 1937; an adult and its larval skin 

 were found together in the pupal chamber; Robert Glen. (C.N.C.) 



LUDIUS RUFOPLEURALIS Fall (?) 



Figure 23, c 

 Ludius rujopleiiralis Fall, Bull. Brooklyn Ent. Soc, vol. 28, p. 188, 1933. 



Three unidentified larvae from Fredericton, New Brunswick, bear- 

 ing strong resemblance to the larva of nitidulus (LeConte) have been 

 regarded as rufopleuralis Fall or arattis (LeConte), the only other 

 North American species included by Brown (1936a, pp. 17-20) in 

 his discussion of the nitidulus group. 



Both of these species occur in New Brunswick and inhabit the re- 

 gions of Canada and the United States from the Atlantic seaboard 

 to Lake Superior, with rufopleuralis continuing as far west as Winni- 

 peg, Manitoba. 



The larvae were found in litter under spruce trees. Cocoons of 

 the European spruce sawfly, Gilpinia hercyniae (Hartig), were abun- 

 dant in this litter and it is probable that the larvae were feeding upon 

 these and other insects. 



These larvae may be distinguished from the European nigricor- 

 nis (?) by having the outer prongs of urogomphi twice as long as the 

 inner prongs, and from nitidulus by the following characters : Nasale 

 and adjoining parts of frons deeply sunken; nasale (fig. 23, c) rela- 

 tively narrow, with tridentate tip, denticles short and narrow and all 

 projecting forward; first prementum with 3 setae just caudad to the 

 base of each palpus, making a transverse row of 6 setae; and basal 

 joint of each labial palpus bearing 2 or 3 setae ventrally. The largest 

 larva examined measured 15 mm. in length, but it was not fully dis- 



