202 THE BRITISH NATURE BOOK 



Family : Silphida. 



Scavengers, living in the bark of trees or in carrion ; straight n- jointed 

 antennae, more or less clubbed. 



Genus Necrophoms. These are the Burying or Sexton Beetles, and have 

 antennae with four joints expanded into a distinct club. These must be 

 highly developed, sensitive organs, which enable the insects to detect the 

 presence of any dead creature within range. A dead mouse or bird is sure to 

 attract them, and they fly with little delay to it. They then proceed to bury it, 

 having legs wonderfully adapted for digging. Several of them work at once, 

 under or round the " corpse," throwing out the soil till the dead body sinks 

 into the hole. The females then lay their eggs in it, so that the larvae on hatching 

 may find an abundance of food. Some species have a distinct musk-like 

 smell (N. vespillo). Another remarkable feature of these beetles is their power 

 of signalling to one another by making a curious clicking sound. This is pro- 

 duced by rubbing a bar which is found crossing the elytra against two files 

 on the top of the abdomen. 



N. humator (the Black Burying Beetle) (Fig. 78). As its name implies, it 

 is a uniform black, except the clubs of the antennae and the claws of the fore- 

 legs, which are orange. 



N. mspator (Fig. 79). About i inch long ; clubs of antennae orange. Two 

 orange bands cross the elytra, the front band of which is not interrupted at the 

 suture ; there is a tuft of golden hair at the tail. Rather local, but quite common 

 where it is found. 



N. mortuorum (Fig. 80). Similar to above, but much smaller about 

 f inch. Antennae entirely black ; two orange bands crossing the elytra, but 

 the upper one is interrupted at the suture ; the lower one is really two irregular 

 patches. 



N. vespillo (Fig. 806). Similar but slightly larger about inch; orange 

 clubs. Distinguished by the golden or yellowish hair on the thorax, abdomen, 

 and scantily on the elytra as well. Fairly common in the South. 



Necrodes (Silpha) littoralis (Fig. 81). The only British species of this genus 

 (Necrodes) ; has longer clubs to the antennae than the above ; pale orange 

 colour. The elytra are flat and long, almost covering the abdomen ; blackish, 

 with a chocolate tint, strongly ribbed. The thorax also has the same bronze 

 tint ; eyes very prominent. Found in carrion. 



Silpha rugosa (Fig. 82). A thick-set, small, flattish species ; very common ; 

 dull black. The elytra are ribbed both horizontally and vertically, giving a 

 rough netted appearance. Head and thorax covered with grey down. 



5. atrata (Fig. 83). Slightly larger (about \ inch), of a bright black ; elytra 

 pitted and crossed by three ribs. Common in carrion and decayed wood. 



S. Icevigata (Fig. 84). About f inch ; not so flat as the preceding ; black, of a 

 medium brightness ; thorax has some grey down. Elytra pitted but not ribbed 

 or grooved. Found in carrion, etc., especially on the coasts in chalky districts. 



