COLEOPTERA — SCOLYTlDyE. 1 1 1 



two interspaces mentioned, these are seen to be smooth and histrous, 

 and appear like shining lines or shallow grooves on the apical declivity. 

 This point is of mxich importance, for it is only by means of it that 

 we can with certainty distinguish this insect from Ilylemius minor." ^ 

 The larva is a white footless grub, with a light canary-coloured head. 

 The middle portion of the grub is yellow, and the tail portion pure 

 white. The pupa is Avhitish and shining, showing all the parts of the 

 perfect insect. 



Preventive and Remedial Measures. 



Though this is certainly a very destructive insect, yet, in the 

 absence of special damage by gales, it can be held in check by fairly 

 good forest management. This consists largely in destroying the 

 breeding-places, which, it must be remembered, are either in the stem 

 of cut trees or in sickly standing trees. Much, of course, will depend 

 on the felling season, and on the interval elapsing before manufactur- 

 ing. If, say, the trees were cut in September and manufactured by 

 March, no evil effects would accrue ; but if they were felled in IMarcli 

 and not cut up at the sawmills until September, it would be entirely 

 to the advantage of the beetle. Hence, if cut during the latter period, 

 various checks should be adopted. For instance, the bark might be 

 partially cut off as in the custom of chipping the "four sides" of the 

 log to lessen railway carriage, which would have the effect of so drying 

 up the bark, or otherwise separating it from the log, to such an extent 

 that the necessary conditions for propagation would be very much 

 destroyed. If, however, the logs are not thus dealt with, then they 

 should be barked at the sawmill from June to August, and all bark 

 burned. Thus many larvae and beetles would be destroyed. 



If, on the other hand, we wish to lessen the breeding-places in 

 standing trees, all sickly trees should be removed. But while the 

 latter may be recommended on entomological grounds, we should bear 

 in mind that "pure" woods of Scots pine should never be heavily 

 thinned, but, on the contrary, an unbroken canopy should always be 

 maintained. Another measure for eradication may be adopted in 

 felling certain trees as catch or trap trees, and then burning the bark 

 of the same. 



From a practical point of view, it may well be asserted tliat the 

 1 Trans. High, aud Agr. Soc. Scot., 1891. 



