Plafypodince.'] RHYNCHOPHORA. 451 



Each burrow is tenanted from its commencement by a pair of beetles; 

 both the beetles and full-grown larvse feed on the wood, and while doing 

 so they eject little rounded nodules of frass which have obviously 

 passed through their alimentary canals ; Hylesinus rraxini and other 

 of the Xylophaga eat the removed materials while forming their 

 burrows, but this is not the case with Plattjfms ; while forming its 

 burrow it throws out the removed wood in very fine splinters which 

 may easily be distinguished from the frass of the wood that has served 

 it for food. Dr. Chapman (I.e. p. 105) gives a very long and interest- 

 ing account of the process of splintering the wood, and suggests, with 

 much reason, that the usual absence, or rather broken condition of the 

 tarsi in older specimens is due to their method of working ; as is well 

 known, the tarsi of fresh specimens are very long and slender, but very 

 soon become much shorter ; Dr. Chapman suggests that at first they 

 may be very useful to the beetles to enable them to suspend the body in 

 a proper position at right angles to the surface of the wood or bark in 

 commencing tlleir burrows. 



When the burrow is some six or seven inches in depth a rounded 

 extremity is made to it, in which the female deposits her eggs, and it is 

 for the time abandoned, the parent beetles commencing the construction 

 of a branch ; eggs appear to be laid as early as the beginning of August, 

 and as late as the end of October, and, as a rule, in recently constructed 

 branches of the burrow ; when hatched the young larvae feed on the 

 fungus above mentioned, and do not begin to eat the wood until almost 

 full grown, when they probably attack it ; when newly hatched the 

 larvae are not straight and cylindrical like the full-grown larvae, but are 

 rather flattened and disc-shaped, the lateral region being largely deve- 

 loped, and each side carrying two rows of large stiff bristles, each 

 bristle surmounting a lateral tubercle ; these bristles are evidently of 

 great use in locomotion ; by their means the larva moves with 

 great ease up and down among its fungiis food until it has grown large 

 enough to occupy the whole diameter of the burrow ; with each change 

 of skin these bristles become smaller, until in the full-grown larva they 

 are only represented by corneous points. 



The larvae feed up rapidly as they are full-grown before the winter ; 

 in spring they excavate the pupal galleries on either side of the ordin- 

 ary burrows ; these are close together, the two sides of a burrow often 

 containing several dozen within a few inches, and are always at right 

 angles to the gallery from which they start ; the Jarvse, after excavating 

 them, must come out and enter backwards, as the head of the pupa is 

 towards the burrow, and the larva is unable to turn round in it ; 

 when the perfect beetle emerges, it soon leaves the biirrow, and 

 either forms a fresh burrow in the stump, or takes wing to a fresh 

 locality. 



The beetles are able to stridulate audibly, by rubbing the abdomen 

 rapidly against the elytra ; when a log containing a number of burrows 



G g 2 



