19 



the species concerned, and with locality and season. In c^eneral terms, 

 it ma}" be said that the best time is after the beetles have laid their 

 eo'gs and before the young or larva? have attained full development. 

 For most species this would be about three weeks after the hrst appear- 

 ance of the beetles in numbers. A spra3'ing of the upper surface is 

 sufficient for most flea-beetles, but for the spinach flea-beetle it is neces- 

 sary to apply a spray to both the under and upper surfaces in order to 

 reach the larvse which feed in exposure on the lower surfaces of plants. 



THE BEET AND SPINACH CARRION BEETLES. 



Among insects particularly attachefl to beet and spinach are two, 

 known respectively as the beet and the spinach carrion beetles. They 

 are nearly unique among carrion beetles (Silphidte) which subsist 

 chiefl}^ on decomposing animal matter, this being the normal habit 

 of the family. The two species in question are also found under 

 carcasses and in garbage. From their dual habit of living both on 

 carrion and on beets and spinach the}" derive their English nam^es. 



THE BEET CARRION BEETLE. 



(Silpha opaca Linn.) 



This species is mentioned in the preface as particularly attached to 

 the beet. In some parts of Europe it is a very serious pest, more par- 

 ticularly in Germany, France, Austria, and England, although it is 

 rather generally distributed on that continent, occurring in Siberia. 

 In Germany it has been described as ''by all odds the most trouble- 

 some pest" with which beet growers have to deal. The species was 

 identified in 1880 from specimens collected in California and *■' Hud- 

 son Bay," and it seems probable that it was introduced on the Pacific 

 coast, and has recently made its way to Nebraska, where it was 

 found attacking beet in 1891." There is some danger that at some 

 future time it may become a more serious pest, such as it now is in its 

 native home. 



The beetle is black and of similar appearance to our common car- 

 rion beetles. The body is elongate, or oblong-oval, with the sides 

 comparatively parallel. It is much flattened, and the elytra at the sides 

 are thin and slightly reflexed or turned up. There is also a small prom- 

 inence near the end of each, the middle costa or ridge of the elytron 

 extends nearly to the posterior margm, and the tip of the abdomen is 

 dull red. The length is about three-fourths of an inch. 



The larvae are shining black, and of similar appearance to our com- 

 mon sowbugs (Oniscus), creatures commonly found in fence corners 

 and in cellars, and they, with their parents and others of their kind, 



«Bruner, Bui. 30 (old series), Div. Entomology, p. 40. 



