NO. II LARVAE OF THE ELATERID BEETLES GLEN 1 37 



which continues through to the New England States, eastern Canada, 

 and Newfoundland. 



Larvae of resplendens acmrhis (Randall) have been collected in 

 Alberta, Saskatchewan, and Manitoba. The other forms of the species 

 are not known in the larval stage. All remarks that follow apply only 

 to the subspecies aerarius. 



The larvae inhabit wooded areas, apparently being present in prac- 

 tically every well-established poplar bluff in the Prairie Provinces, 

 as well as in all extensive forests. Specimens have been taken from 

 decaying stumps and logs of poplar, willow, and pine, but are usually 

 more abundant in the leaf litter beneath such trees. The species is 

 obtained occasionally from native shrub thickets. In the late autumn, 

 larvae have been found in the soil, just under the litter, probably in 

 preparation for hibernation. 



The species is not known to be of economic importance. In cap- 

 tivity a larva was observed to attack and partially devour a cutworm. 

 A wood-feeding habit is also suggested from finding in a fresh burrow 

 in a chip of wood a larva with its head at the blind end of the tunnel. 

 Pupation and ecdysis usually take place in cells made in wood. The 

 pupa appears in late July and, under laboratory conditions, trans- 

 forms to the adult in about 12 days. All adults found in late autumn 

 were in twigs, logs, and stumps, many still within their pupal chambers. 



In structure, the larva of resplendens aerarius exhibits fundamental 

 Athous and Elathous characters, but does not fall in any known "spe- 

 cies group." It is most readily identified by the ninth abdominal seg- 

 ment (fig. 26, /), especially by the blunt outer prongs of urogomphi 

 (opr, fig. 26, e, /), the small caudal notch (en), the median dorsal 

 groove (mg), and the blunt "teeth" (to) on the margins of the 

 dorsum. Valuable supplementary characters are the yellow-brown 

 color; the abdominal mediotergites( fig. 26, c) with long impressions, 

 but lacking other prominent sculpture ; the presence of eyes ; triden- 

 tate nasale (fig. 26, a) ; shape of the base of the ungula (fig. 26, d) ; 

 and the presence of several minute setae just behind the large an- 

 terior seta in each dorsal head sulcus (fig. 26, b). 



Description of "mature" larva. — Length 21 mm. ; greatest breadth 

 2.75 mm. on fourth abdominal segment. Fully distended larvae mea- 

 sured up to 23 mm. Body robust, with large membranes on lateral 

 aspect; all segments broader than long; head and ninth abdominal 

 segment about two-thirds greatest body width. Dorsum yellowish 

 brown (near "amber brown," Ridgway, 1912), mesothorax, pro- 

 thorax, and head somewhat darker, mandibles, nasale, talus, and 

 prongs of urogomphus considerably darker; venter slightly paler, 



