COLEOPTEEA OE BEETLES. 



147 



The Beet Carkion-bbetle (Silpha opaca). 



This beetle has become a regular mangold pest. Originally 

 it was a scavenger only, feeding on dead carcasses of birds and 

 mammals as they lay on the ground ; but its larvae feed upon 

 the leaves of the wurzel, and have done so since at least 1844, 

 when Curtis reports an attack of this beetle, since which time 

 numerous attacks have been reported. There are two species 

 that do the harm — S. opaca and S. atrata ; the former is very 

 destructive to sugar-beets in France. The beetle is nearly half 

 an inch long, flattish in shape, dark-brown in colour, and when 



Fig. 65. — Beet Carrion-beetle i^iX-gha opoca). 



1 and 2, Larvae, natural size ; 3 and 4, different stages of larvae, enlarged ; 6, female ; 

 6, male. (Curtis.) 



fresh, covered with a reddish-brown down, which rubs off, when 

 the elytra appear black ; each elytron has three sharp ridges 

 running along it, and between the second and third ridges is a 

 dark spot ; the edges of the wing-shields are turned up, tip of 

 abdomen tawny-red. 8. atrata is also common : it is a black 

 and shiny species without the ridges on the wing-cases. We 

 find the beetles under dead animals and birds in the spring, and 

 in the winter amongst moss and under stones and wood. The 

 female lays her eggs on decaying leaves and on the ground ; in 

 two weeks the larvae appear, and feed off the wurzel for about 

 three weeks, when they pass into the soil and form a cell in 

 which they pupate, and from there the adult beetles come in 



