1869.] 



199 



attacks the bark. In the genus Ilylesinus, and others of this family, the parent 

 beetles make a long straight burrow, and the eggs are deposited more or less 

 regularly along either side. Unlike these, Cryphalus hinodulus makes what may 

 be called a little irregular cavern rather than a burrow. This is always imme- 

 diately beneath the outer bark, and does not penetrate to the wood. I find 

 invariably a pair of beetles in each cavern, even when nearly all the eggs are 

 deposited, or when the eggs are hatched ; these are laid in little confused heaps in 

 the recesses of the cavern, sometimes all in one heap, generally in three or four, 

 and to the number of from 30 to 60. The larvae when hatched burrow without 

 any regularity, but tend to travel in a vertical direction. They are footless grubs, 

 with strong jaws, and a distinct head like the larvae of the other Xylophaga. I 

 found that the eggs laid in May had in August produced some perfect beetles, 

 though many still remained in the larval and pupal states. This has also been the 

 case this season with Hylesinidce. I have been watching, and I suspect that this 

 species, like the others, does not usually come to maturity until a month or two 

 later, and then hybemates before emerging. This species appears only to attack 

 the living trees, and though so minute, is from its numbers able to cause the des- 

 truction of any tree it colonises. A branch is usually first attacked by several 

 pairs, whose progeny then, laying their eggs in it, complete its destruction. 

 Wherever a brood has been reared a wide rough crack is observable in the bark, 

 and a destroyed branch presents the same appearance in an exaggerated form ; the 

 whole bark looks bloated and cracked, and is pierced by the exit holes of the 

 beetles. A branch is probably often attacked in sufficient force to destroy it in 

 one season, and I have already mentioned my belief that the destruction of a whole 

 tree has been accomplished during the present season. The trunk is rarely at- 

 tacked till most of the branches are dead, and its vitality is then so much reduced 

 that no distortion occurs from their ravages, except of course that it soon becomes 

 quite decayed. 



On the same aspen trees that were blown over there was a quantity of ivy, 

 and the bending'of its stems, where it was torn down, had proved as injurious to 

 it as if it had been cut across. This has fallen a prey to Hylurgus jpilosus, rare as 

 a British insect. Odd specimens occur ; but as no one in this country has remarked 

 upon its habits, it has never been found in any quantity. I have found it in almost 

 any ivy that was in proper condition for its attack. Neither healthy living ivy, nor 

 faggots cut from the tree, suit its taste, but when sickly and dying, it is at once 

 attacked. There is a fashion of treating ivy, observed in many districts, of simply 

 cutting across or removing an inch or two from the stem, the result of which, as 

 is well known, is not the immediate death of the plant, which usually survives for 

 a year or two. The back of either the upper or lower (but usually the upper) 

 section of ivy so treated is a favourite habitat of Hylurgus pilosus. In this the 

 parent beetle makes a burrow of about an inch in length, often half round the 

 stem, and the eggs are laid rather irregulai-ly along its sides and covered over with 

 frass. The larvae eat galleries at right angles to this, and sometimes travel as 

 regularly and symmetrically as those of Hylesinus fraxini. When examining ivy 

 for the beetle last spring, I found several shallow grooves, usually on smaller stems 

 not suitable for oviposition, and along the side in contact with the supporting tree. 

 These were often untenanted, and had been obviously merely eaten as food by the 



