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ON THE SPECIES OF SCOLYTUS, A GENUS OF BARK 

 BEETLES, FOUND IN THIS DISTRICT. 



By T. ALGERNON CHAPMAN, M.D , Abeboavennt. 



The genus Scolytus belongs to the family Hylesinidce, which has also, 

 from that circumstance, been called Scolytidse, the best English equivalent 

 of which is Bark-beetles. The typical species, Scoli/tua Destructor, was called 

 Bylesiniis Scolytus by Fabricius, and its specific name was applied to the 

 whole genus by Olivier, who substituted that of Destructor. The several 

 species have a strong resemblance to each other. They have a quaint, rtilted 

 appearance from the bending down of their heads, and the truncation of their 

 elytra and tei-minal segments ; and they run in a rapid, jerky manner. They 

 all have a rounded, shining, black, somewhat punctated thoi-ax, with indications 

 of reddish marking in some specimens. The reddish elytra form a more or less 

 square, flat surface, and are longitudinally striated, the peculiaiities of the 

 striie forming the characters which are most readily seized for the discrimination 

 of the several species. 



There are six British species, one of which, Scolytus Batzburgii, Jans,, 

 has been taken, on only one occasion, in Perthshire. I have failed to find it in 

 this district. It is a Birch feeder, and I have little doubt is to be met with 

 wherever that tree is plentiful, but I don't know of any such place near Aberga- 

 venny. I have met with the five other species, and of these I show you both 

 living and mounted specimens. 



Scolytus Destructor OL is the largest of these, and the most common one. 

 Its habitat is the bark of elm. The size of the timber it affects makes it difficult 

 to exhibit good specimens. It may be found at this season (June) making its 

 galleries of oviposition in any elm trees felled during last winter, and usually in 

 such numbers as to ensure the destruction of the bark. I do not recollect to 

 have seen it in timber smaller than Sin. in diameter. The female makes her way 

 along the bottom of some crack in the bark, often by widening it for some dis- 

 tance, before commencing to burrow, so that the real opening of the gallery is 

 some distance from where the little heap of out-turned frass lies which marks its 

 orifice. The male is present for only a brief interval, viz., after the burrow is 

 well commenced, but before any eggs are laid. The burrow is usually about 

 three inches long (very rarely five), almost always close to the wood, and slightly 



