THE TAILED WASP. 233 



large size, the injury they do to the timber is some- 

 times very considerable. 



The largest and most destructive species is the 

 Urocerus (or Sirex] gigas, the female of which usually 

 measures about an inch and a half in length. It is 

 of a fine yellow colour, with the head and thorax, the 

 base of the abdomen beneath, and a broad baud across 

 its middle above, black, which is also the tint of the 

 hinder thighs, and the bases of all the others. The 

 rest of the legs, the antennae and the eyes, are yellow ; 

 the abdomen is terminated by a pointed tail nearly a 

 quarter of an inch in length, and beneath this the 

 ovipositor is seen projecting about half an inch from 

 the point where it issues from the abdomen. It flies 

 with a loud humming noise, almost as strong as that 

 of the well-known Humble Bees. The male is con- 

 siderably smaller than his partner, and has the abdo- 

 men yellow, with the base and apex only black, 

 whilst the hind legs are black with yellow rings ; but 

 both sexes vary a good deal as to size and colour. 

 Although natives of the pine forests, this and the 

 allied species, which are for the most part rare in this 

 country, occur occasionally in towns, and even in the 

 heart of cities, to which they are conveyed, like other 

 wood-loving insects, whilst lying in the pupa state in 

 the interior of wood brought in either for timber or 

 firing. Thus the Urocerus gigas sometimes makes 

 its appearance in newly-built houses in London and 

 its suburbs, to the great astonishment of the inha- 

 bitants ; but the specimens which occur in this way 

 must be considered as for the most part imported 

 from abroad with the timber used in the construction 

 of the houses. 



The Xiphydria Dromedarius, a small species of this 



