222 



COLEOPTERA 



Those of the buiying-heetles have spiny plates on the back of the 

 body, and do not resemble the othei' known forms of the family. 

 The rule is that the three thoracic segments are well developed, 

 and that ten abdominal segments are also distinct ; the ninth 

 abdominal segment bears a pair of cerci, which are sometimes 

 elongate. Often the dorsal plates are harder and better developed 

 than is usual in Coleopterous larvae. This is especially the case 



with some that are en- 

 dowed with great powers 

 of locomotion, such as *S'. 

 ohscura (Fig. 104). The 

 food of the larvae is as a 

 rule decomposing animal 

 or vegetable matter, but 

 some are predaceous, and 

 attack living objects. 

 The larger SiliAa larvae 

 live, like the Necro- 

 pliorus, on decomposing 

 animal matter, but run 

 about to seek it ; hence 

 many specimens of some 

 of these large larvae may 

 sometimes be found amongst the bones of a very small dead bird. 

 We have found the larva and imago of >S'. thoracica in lairds' nests 

 containing dead nestlings. ^S'. atrata and ,S'. laevigata make war 

 on snails. S. lapponica enters the houses in Lapland and ravages 

 the stores of animal provisions. S. oimca departs in a very 

 decided manner from the habits of its congeners, as it attacks 

 beetroot and other similar crops in the growing state ; it is 

 sometimes the cause of serious loss to the growers of beet. The 

 larvae of the group Anisotomides are believed to be chiefly 

 subterranean in habits ; that of A. cinnamomea feeds on the 

 truffte, and the beetle is known as the trufiie-beetle. 



The number of species of Silphidae known must be at present 

 nearer 900 than 800. Of these an unusually large proportion be- 

 long to the European and North American regions; Silphidae being 

 apparently far from numerous in the tropics. Eather more than 

 100 species are natives of Britain. The family reappears in con- 

 siderable force in New Zealand, and is probably well represented 



Fig. 104.— a, Larva 



(After Schicidte). 

 Australia. 



SUpha obscura. Europe. 

 Ptomaphila laorymosa, 



