708 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



bodies are bearded serve as a brush to sweep this dust into these lateral 

 openings. Thus the mouths of these notches become filled and the eggs 

 therein covered and concealed from auj: predaceous insect which may 

 enter the burrow after the parent has completed her work and before 

 the eggs have hatched and the young have mined their way beyond 

 the reach of such enemies. The female continues her operations until 

 her stock of eggs is exhausted, forming a burrow from 4 to 8 inches or 

 more in length. 



" The eggs of this beetle are about 0.025 long, of a broad, oval shape, 

 and a watery white color. They may be met with in their newly formed 

 burrows beneath the bark the forepart of June. They probably hatch 

 in ten ta twenty days, according to the temperature of the atmosphere 

 at this time. The infantile larva is invariably found lying with its back 

 towards the sawdust with which the notch in which it is bred is tilled, 

 its mouth being thus brought in contact with the soft innermost layer 

 of the bark at the extremity of the notch — the elastic nature of the saw- 

 dust probably aiding in pressing its mouth against its destined nourish- 

 ment. Thus it has only to part its jaws and close them together again 

 to fill its mouth with food. And by repetitions of this motion a cavity 

 is gradually formed between the bark and the wood, into which its head 

 sinks, and afterwards its body. This cavity consequently takes a direc- 

 tion outwards at right angles with the central burrow. And thus the 

 l^rva eats its way onward until it has obtained its growth, forming 

 hereby a gallery varying in its length from about 1 to 3 inches, 

 as the material consumed has been of a quality more or less nutritious, 

 and winding and turning where impediments have been encountered or 

 the track of another larva has been approached. Many of these lateral 

 galleries, howes^er, end abruptly before they are half completed, the 

 worm having been destroyed by insect enemies or some other casualty. 

 And it is curious to notice how these little creatures respect the terri- 

 tory which is already in possession of another, changing their course to 

 avoid any encroachment thereon; and if one of them finds himself so 

 surrounded and hemmed in by other tracks that it becomes impossible 

 for him to refrain from encountering them, he so shapes his course as 

 to cross his neighbor's road as nearly as possible at right angles instead 

 of obliquely, thus intruding thereon as little and for as short a time as 

 possible. Sometimes also two females happen to excavate their galle- 

 ries parallel with each other, and so near that no adequate space remains 

 between them for their young to mine their burrows, the beetles having 

 been unaware of their proximity, no doubt, until too much labor had 

 been expended to admit either one to abandon the ground and go else- 

 where. In such cases the eggs are all placed along the outer side of 

 each gallery, and thus the larvae all mine their way outward in opposite 

 directions to each other. 



The larva is a plump soft white worm, broadest anteriorly, and with 

 its body bent into an arch or having its tail turned partially inward 



