140 PROTECTION OF WOODLANDS. 



B. amitinus is also an 8 -toothed bark-beetle, so very closely 

 resembling B. typographies in outward appearance, and in its 

 habits and life-history, that it is very frequently mistaken for the 

 latter. It is, however, found on the Scots Pine and the Larch as 

 well as on the Spruce ; and the often-reported finding of the 

 Spruce bark-beetle on the Larch is probably in reality the occur- 

 rence of B. amitinus, which also appears to be very commoa 

 Similar preventive measures and exterminative remedies must be 

 adopted against it as have been described for B. typographies. 



66. The 6-toothed Spruce Bark-beetle, Bostrichus (Tomicus) 

 chalcographus. 



(Fwfc Plate! fig. 15.) 



This is one of the smallest of the bark-beetles. It is only 

 about 0*06 to 0'08 inches in length, almost hairless, with a fatty 

 kind of gloss ; it has a dark thorax, but is otherwise reddish-brown, 

 and its elytra, though dotted near their base with fine rows of 

 punctures, are smooth towards the ends, and carry on both sides 

 3 dark coloured, tooth-like protections near the end (hence the 

 name 6 -toothed). 



It is chiefly to be met with on Spruce trees, but has also been 

 found on all other conifers. It is an almost constant attendant 

 on B. typographies, but is then usually to be met with principally 

 in the upper portions of the stem, and on the main branches, in 

 places where the bark is thinnest ; it also occurs in pole-forests 

 that are sickly or backward in growth. The main galleries 

 formed by it are quite characteristic, as 4 or 5 of them radiate, 

 star-like, from the copulating chamber ; they are of course, as 

 also the larval galleries, much smaller than the corresponding 

 galleries formed by B. typographus (vide Plate ! fig. 15). Its 

 habits and life-history resemble those of the last-named species, 

 B. chalcographus having undoubtedly also a double generation 

 within the year. It swarms a little earlier than B. typographus, and 

 by making its attacks always in the upper portions of the stem, 

 it soon brings the tree into a sickly sort of condition, thereby 

 rendering it a favourable breeding-place for that more danger- 

 ous species. 



The preventive measures and exterminative remedies are practi- 



