Insects, 



527 



former have, too, not rarely a powdery matter, derived from 

 the gnawed bark, discernible near them. I premise this for 

 the sake of stating that the perforations observable in nearly 

 all the fourteen trees have been made this summer by entering 

 parent Scolyti ; and I say " nearly all the fourteen," to pre- 

 clude it being objected that a few of the perforations to be 

 found upon two or three of the trees have been made by 

 Scolyti making egress from within in a previous season. About 

 fifty larvae it seems {Jig. Q^. b, c) are hatched from the quantity 

 of eggs introduced by a single parent Sc61ytus, and as every 

 perfect Scolytus which is developed from these larvae gnaws, 

 for its own egress, a distinct hole, plenty of these holes may 

 be expected to be visible after May, in 1835. {Jig. 64.) 



Seven of the fourteen trees, be- 

 sides being perforated by the 

 parent Scolyti, have been sub- 

 ject to a considerable extrava- 

 sation of sap : this, one is led 

 to perceive, by observing the ac- 

 tions of the flies so abundant, as 

 noticed above, upon the surface 

 of the bark of the stems and 

 larger branches. Those of the 

 flies which are alive are busily 

 occupied in licking the sap from 

 the natural fissures of the bark, 

 from larger openings in it occa- 

 sioned by past wounds or de- 

 fects, and some, also, it is right 

 to state, from the orifices of the 

 perforations made by the parent 

 Scolyti. Those of the flies which are dead are, however, 

 more numerous than the living ones, and they adhere, in the 

 posture of life, over all parts of the bark of the trees, here 

 scatteredly, there in clusters in the neighbourhood of some 

 opening which had yielded an effusion of sap, and they are 

 in all stages of decay, from those fresh dead, to those with 

 loosened wings shaken by the breeze, to those without wings, 

 and those a mere whitened mass, in which scarcely the form 

 of a fly remains. There were some dead flies attached to the 

 under surface of a few of the leaves. The flavour of the sap 

 is, to my taste, much that of slightly sugared water, and it is 

 probable that the great number of flies which have died here 

 have died of repletion, rather than of any poisonous property 

 in this sap taken by them as food. Of the clusters of flies, 

 it should be observed, that there w^ere also some clusters or 



