NO. II LARVAE OF THE ELATERID BEETLES GLEN 1 59 



THE LIMONIUS AENEONIGER GROUP 

 Figures g, g ; 11, a; 30, a-d, f 



Only two species are included in this group, one from Europe, 

 the other from western North America. The larva of the genotype, 

 Lhnonius aeneoniger (DeGeer) (= Pheletes Bructeri Panzer), is 

 recorded by Beling (1884, p. 205) from earth in dry, sunny places 

 in European forests, preferably under moss. H. P. Lanchester, of 

 Walla Walla, Wash., collected larvae of the Pacific coast species, 

 L. consimilis Walker, "in moss on boulders in shade." 



This strongly characterized group is distinguished as follows : 

 Mandible (fig. 30, c, probably considerably eroded) with prominent 

 toothlike expansions anterad to retinaculum; nasale (n, fig. 30, a, b) 

 short, with 3 subequal teeth; subnasale (sn) with i prominent obtuse 

 tooth ; and abdominal mediotergites with transverse branches of im- 

 pressions short, extending less than one-half distance from longi- 

 tudinal branches to middorsal suture. 



Preserved larvae are yellow to yellow-brown in color, with head 

 and prothorax darker, but living specimens appear to differ since 

 Beling (1884, p. 205) reports "larva intense yellow-red" and Lan- 

 chester (1941, p. 368) records consimilis as "orange-yellow" when 

 collected. Both are relatively small species, aeneoniger attaining 9 

 mm. in length, and the largest consimilis examined measuring 13 mm. 



Urgomphi (ur, fig. 30, /; fig. 30, d) with outer prongs (opr) very 

 small. Ninth abdominal segment (fig. 30, /) without mediodorsal 

 groove (sometimes with a shallow, central, subcircular depression) ; 

 without setae on central dorsal area; "teeth" (to) very small, prac- 

 tically wanting, on lateral aspects of dorsum ; and distance between 

 caudal notch and pleural area about one-fifth length of segment, 

 exclusive of urogomphi. Frontoclypeal area (fig. 30, a) truncate or 

 broadly rounded posteriorly. Paranasal lobes (pnl) without definite 

 pore cluster. Eyes present. Two prominent unpaired lateroepicranial 

 setae on each gena. Without setae on ventral aspect of basal segment 

 of labial palpus. Mesothorax and metathorax without spinelike setae 

 on episterna (usually i fine seta on each episternum). Abdominal 

 mediotergites finely punctured and each with 2 or 3 pairs of setae 

 in posterior transverse row. 



Material used in study. — L. aeneoniger (DeGeer) : Only 2 speci- 

 mens were available for examination, i from Norway, the other 

 from Denmark. As far as is known, neither of these was associated 



