COLEOPTERA SCOLYTID^. 99 



whip of the antennae is seven-jointed, the club acorn-shaped and not 

 severely compressed. 



There are two species, more or less generally distributed throughout 

 the country viz., H.palliatus and H. ater which may be considered 

 as the more important arboreal species. 



Synopsis of the Species. 



Thorax not very long, and rugged at sides. Elytra distinctly reg- 

 ularly punctured. Centre line raised. In stems of spruce or 

 Scots pine ...... Hy. palliatus. 



Thorax longer than broad, sides of pronotum almost equal and 

 parallel. Centre line of thorax not raised. In stems of young 

 Scots pine near the root ..... Hy. ater. 



Hylastes palliatus (Gyll.) 



The beetles hibernate in dead trees, and appear about the latter 

 end of March or beginning of April. They generally select spruce- 

 trees which have been felled the previous winter, and it is best to 

 look for them on stems of trees lying on the ground, especially where 

 the branches have been cut oft' by the woodman's axe. If the wood- 

 man should have made a few false blows, and not have done his work 

 very well, the imperfect result is an advantage to the beetle, inasmuch 

 as the jagged pieces form a sort of lodgment, and often quite a colony 

 of twenty or even more beetles may be found in such places. 



The larvae appear about the latter end of April or beginning of 

 May. The arrangement of the markings is very difficult to follow. 

 At first the mother-galleries are perpendicular, but they often deviate, 

 and the larval galleries may radiate in any direction. Thus we 

 simply get a confusion of markings. 



In comparatively large stems of spruce we generally find the 

 markings made in the bark, but in branches of Scots pine we find 

 them on the wood. Fig. 91 is taken from a Scots pine branch. 



Eichhoff says that this species is double-brooded. This is so in 

 some cases in Northumberland, and often the second brood remains 

 fully developed within the bark, and swarms in spring. Again, I 

 have found that this species is often single-brooded in Northumberland, 

 so that as regards life-history the matter requires further elucidation. 



