132 ON THE NATURAL HISTORY OF BEETLES 



known throughout the United Kingdom, which may he specified 

 as follows : — 



Hylurgus pinijperda, Linn. 

 „ rufus, Mars. 

 „ obscurus, Mars. 

 „ picens, Mars. 



Hylurgus angusiatus f Gy 11. — ater, 

 Mars. 

 „ rhododactylus, Mars. 

 „ ater, Fab. = niger, Mars. 

 „ Boleti, Mars. 



They are found principally in June, July, and August, under the 

 hark of the trees they have attacked. Hitherto it seems to have 

 been the general opinion that they molested only diseased or decay- 

 ing and feeble trees. Some authors even assert (Selby amongst 

 others) that in no single instance have they ever been known to 

 attack a tree in perfect health ; but this point we have already re- 

 ferred to in this paper, and we think it is conclusively shown, from 

 recent observations of their habits, that, in their incipient stages of 

 attack, so insidious are their movements, that it is only after a time 

 their presence is detected, and then the vigour of the tree has 

 already begun to decline, and thus the insect is assumed to be the 

 result rather than the cause of the tree's failure. 



As it would be impossible within our prescribed limits to describe 

 and specify all the insects which are injurious to the pine family, 

 or whose ravages tend to retard the progress of that interesting class 

 in our gardens and arboreta, we can only name a few others whose 

 predatory habits are well known in certain localities, before passing 

 on to notice some of the means of prevention which appear at least 

 feasible, if not thoroughly effectual, for the prevention of the pro- 

 gress of the mischief which these animals occasion. 



In some situations the Emobius mollis (Linn.) is frequently 

 found upon both Scots fir (P. sylvestris) and Pinus maritima. Like 

 the Hylurgus pinijperda, it lives at the expense of the tree ; but 

 Perris (a French naturalist) asserts that it only attacks sickly or 

 ailing plants. To this, as has already been stated, we object, and 

 need not recapitulate the reasons. Blastophagus piniperda (Linn.), 

 Hylastes ater (Payk.), and Hylastes palliatus (Gyll.), which in 

 some places is very abundant, are all extremely destructive. 



One of the most fatal enemies of the silver fir (JPicea pectinata), 

 and which it is to be feared is increasing in many parts of the 

 country, especially in low-lying situations and in deep or heavy 

 soils, is the Bostriclms typograplius (Fabr.) This insect confines its 

 attacks to the leading shoots of the tree. These it disfigures by 



