NO. II LARVAE OF THE ELATERID BEETLES GLEN 45 



The larvae are believed to be predaceous, feeding upon the cocoons 

 of the European spruce sawfly, Gilpinia hercyniae (Hartig), being re- 

 ported in a personal communication from R. F. Morris, Fredericton, 

 New Brunswick. 



In structure, the larva is identical with that of L. aeripennis and 

 L. aeneiis and separation is most readily secured through differences 

 in distribution. 



Material used in study. — Three larvae were examined. These were 

 not identified through rearing, but were collected from litter under 

 spruce in Sunbury County, New Brunswick. On the basis of struc- 

 ture these larvae belong unquestionably to the aeripennis group and 

 the locality fits the known distribution of appropinquans. (Canadian 

 national collection.) 



LUDIUS PRUmiNUS (Horn) 



Figures 13, i; 15, a-c 



Corymbites pruinimts Horn, Trans. Amer. Ent. Soc, vol. 3, p. 320, 1871. 

 Ludius priiinostis Schwarz, in Wytsman's Genera Insectorum, pp. 46, 226, 1907. 

 Corymbites noxins Hyslop, Proc. Biol. Soc. Washington, vol. 27, p. 69, 1914. 

 Ludius pruininus (Horn), Brown, Canadian Ent., vol. 67, p. 135, 1935. 



The range of pruiiiimis is indicated by Brown (1935b, p. 135) as 

 bounded by Nebraska, California, and the Okanagan Valley of British 

 Columbia. Lane (1925, p. 91; 1935, pp. 529-530) states that the 

 distribution is governed by rainfall, the species occurring only on 

 the semiarid sagebrush and bunchgrass regions which have an annual 

 rainfall not exceeding 15 inches. This species is a serious pest of 

 grain crops in the dry-farming districts of the area, but disappears 

 in a few seasons from fields brought under irrigation. According to 

 Hyslop (1915a, p. 13) and Lane (1931, p. 5) pupation may occur 

 during the third year of larval life or from one to several years 

 later, probably depending upon environmental conditions. The pupal 

 chamber is constructed from 4 to 8 inches below the soil surface, 

 usually in the hard soil just below the tillage line. 



The larva is figured by Hyslop (1915a, p. 12, fig. 4), but no de- 

 tailed description or comparison with closely related species is given. 



Ludius pruininus is readily distinguished from L. aeripennis by 

 possessing the following characters of the ninth abdominal segment 

 (fig. 15, a) : Four setae on central dorsal area; narrower and sharper 

 "teeth" (to) on sides of dorsum; and paramedial impressions (pirn) 

 on dorsal plate usually distinct posteriorly, although coming close to- 

 gether and sometimes lying within a shallow median concavity. 



