76 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. Ill 



e, f), antennae (fig. i8, d), sternum of the first 5 abdominal segments 

 (fig. 18, c), and impressions on abdominal mediotergites (fig, 18, h). 

 Larvae of the triundnlatus group are yellow or yellowish brown. 

 Caudal notch large, U-shaped or V-shaped. Urogomphi bifid with 

 subequal prongs; tip of outer prong smoothly rounded. Ninth ab- 

 dominal segment without setae on central dorsal area, and with 3 

 "teeth" on lateral margins of dorsum. Nasale unidentate, with 2 setae 

 on each side of base in sinuosities between nasale and paranasal lobes. 

 Second joint of antenna bearing 2 "sensory" appendices. Basal joint 

 of labial palpus without setae. Eyes present. Gula short, but relatively 

 wide. Frontoclypeal area bluntly rounded posteriorly. Mandible with 

 short, shallow, inconspicuous dorsal groove. Presternum of prothorax 

 divided into 4 pieces. Episterna of mesothorax and metathorax with- 

 out spinelike setae. Mediotergites of first to eighth abdominal seg- 

 ments with prominent setae unpaired (at least not definitely paired) ; 

 on mediotergites of second to fifth abdominal segments the transverse 

 branches of impressions usually reach to or almost to the middorsal 

 line. Sterna of first to fifth abdominal segments divided by deep 

 lateral sutures, usually closed in segments 6 to 8. 



LUDIUS TRIUNDULATUS (Randall) 



Figures 13, g; 14, d; 18, a-d, f, g 



Elater triundulatus Randall, Boston Journ. Nat. Hist., vol. 2, p. 12, 1838. 

 Ltidius triundulatus (Randall), Brown, Canadian Ent., vol. 68, p. 106, 1936. 



This species is known from the northeastern United States and 

 from coast to coast in Canada. 



The larvae have been found in abundance in damp litter and in very 

 rotten wood under well-grown aspen poplar, but have also been 

 collected from duff and decayed stumps under stands of willow, 

 spruce, and pine. Larvae have been known to attack the cocoons of 

 the European spruce sawfly,^ Gilpinia hercyniae (Hartig), and it is 

 concluded that they are chiefly predatory. In western Canada, trans- 

 formation to the adult state appears to occur normally in July, pupa- 

 tion usually occurring in the first half of the month, but adults have 

 emerged in August from material collected in eastern Canada. Under 

 laboratory conditions the pupal period lasts about i week. 



In structure, the larva is very similar to that of nebraskensis 

 (Bland) ( ?), differing only in characters of the ninth abdominal seg- 

 ment (fig. 18, f, g). 



7 Information taken from labels accompanying larvae sent to the Saskatoon 

 laboratory by R. E. Balch, Entomologist in Charge, Dominion Entomological 

 Laboratory, Fredericton, N. B. 



