168 INSECTS. 



bullets are said to have been found with circular holes 

 drilled by the Sirex juvencus. Whether, however, 

 these were bored by the ovipositor of the female, or were 

 eaten out by the small strong jaws of the larva, is not 

 stated ; nor is any suggestion offered as to the purpose 

 to be served in either case. 



The Fir is especially subject to the attacks of the 

 Woodborer, but it is to be found upon several other trees, 

 as the Willow and the Hornbeam. 



One large species, the Sirex Gigas (see PL VI. fig. 2) 

 is well known in England, rather owing to its conspi- 

 cuous size than to the frequency of its occurrence. It 

 can hardly be called a British species, being probably 

 imported in the larva or pupa state in foreign timber, 

 and, so far as is known, not multiplying here. 



The larva is an eyeless grub, the legs are only six in 

 number, the insect being destitute of the " false " legs 

 found in Tenthredo, and the body ends in a horny 

 prickle. 



The final transformation is said to take place within 

 the wood excavated by the larva, after the formation, 

 by the larva, of a " silken cocoon mixed with chips and 

 excrement" 



Only about ten species of Woodborers are known in 

 England. 



