188 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 12 



Length of the Lakval Stage 



Years No. Larvae Min. Days Max. Days Average Days 



1915-16 3 329 355 338.3 



1916-17 25 292 329 305.2 



1917-18 22 311 346 329.1 



Average 317.7 



Pupa. — The pupae of Eleodes opaca (Plate 8, C) vary from 13 to 15.5 

 mm. in length, and from 3.5 to 5.5 mm. in width. They are white in 

 color with semitranslucent appendages. This color changes as devel- 

 opment takes place, the body becoming creamy yellow and the 

 appendages reddish brown. In general, the pupae resemble those of 

 E. clavicornis described by Blaisdell (1909, pp. 500-501), with certain 

 modifications noted by Swenk (1909, p. 335). 



Pupation occurs in the field during April, May, and June. In 1915, 

 pupation began about April 20, reached its maximum May 4, and was 

 practically over by June 1. The spring of 1918 was cold, and pupation 

 did not begin until May 7. The maximum was reached about May 

 20, and pupae were to be found until the last of June. Before pupating, 

 the larva constructs a. spherical cell from one-half to two inches below 

 the surface of the ground. Here it remains in a quiescent state for 

 about a week before transforming to the pupa. The length of the 

 pupal stage has been determined for 149 pupae, the pertinent data being 

 shown in the following table : 



Length of the Pupal Stage 

 Year No. Pupae Min. Days Max. Days Average Days 



1915 50 13 25 20.6 



1916 4 9 13 11.5 



1917 19 8 11 9.6 



1918 76 8 23 11.1 



Average 14.1 



Adult.^ — The adult beetles (Plate 8, D) are fusiform oval in shape, 

 black in color, and sparsely covered with whitish hair. The dorsum of 

 the elytra is quite flat. The female is more or less broadly oval in 

 shape and the abdomen is rather strongly convex. The anterior tarsi- 

 are unmodified. The male differs from the female in that the body is 

 narrow and the abdomen is but slightly convex. The first two seg- 

 ments of the anterior tarsi are slightly widened and clothed with two 

 dense pads of spongy pubescence. The males are 10 to 12 mm. in 

 length, and about 5 mm. in width. The females are somewhat larger 

 in size, being 11 to 14 mm. in length, and 5 to 7 mm. in width. 



Emergence begins about the middle of May, and continues through 



