170 JOURNAL, BOMB A Y NA TURAL HISTORY SOCIETY, Vol. XV. 



the subject of the life-histories and developments of some of her com- 

 monest insects, and how urgently recruits in this department of know-s- 

 ledge are required. Instances could be enumerated of insects which, 

 if sought for in their abodes beneath the bark or in the roots, in the 

 twigs or on the leaves, &c, are to be found almost as plentifully as the 

 common house fly and throughout the same period in the year, and yet 

 neither their eggs, larvae nor pupre are yet known. 



Leaving the bark and cambium layer of older trees, we will 

 now turn 1o young saplings and the smaller branches of the older trees. 

 A search in this direction may show that grubs have gone into the 

 iuterior of the stems and are boring their way up or down the centre. 

 This will probably be the work of longioorn beetles or of the wood- 

 boring moth larva?. In the wood of older dead trees round shot holes 

 or large oval galleries may be found riddling it through and through, 

 the work of the wood-boring families of insects, the wood-wasps (Sire.v) 

 and boriug beetles and their larvre or boring moth caterpillars. Or 

 on the branches again, white or variously coloured scaly masses may be 

 visible, which, on a closer examination, are seen to be alive. These are 

 scale inseets (Cocadai) sucking out the sap of the branch. Our search 

 need not terminate here however. There still remain the roots of the 

 tree, and to get at these it will be necessary to excavate the earth all 

 round so as to leave them exposed in a pit where they can be examined 

 satisfactorily. Here again wo shall find many members of the Insect 

 World. Aphids sucking out the sap, the very life of the young tree, 

 bark-borers, wood-borers, and their attendant predacious and parasitic 

 companions, sap-feeding beetles and dead bark eaters — some or all may 

 be present, the individuals being probably of entirely different genera 

 and species, if not families, to those working higher up in tbe trunk, 

 main branches, twigs, or on the leaves and in the fruit and seeds of the 

 tree. If we leave the tree and turn to the nearest field of crops, we 

 shall find tbe same state of affairs. Leaves, stems, roots, flowers and 

 seeds or fruits, all will be found to support, either externally or inter- 

 nally, their quota of Insect Life, some feeding upon the plant, others 

 predacious upon the crop pest. If anything occurs to disturb Nature's 

 balance of power, e. g., if some particular crop plant or tree, &.C., is 

 grown in conterminous patches in fields or forests over large areas, given 

 a favourable season to Insect Life the pest or pests partial to it may 

 increase rapidly in enormous numbers, the food-supply and conditions 

 being so favourable. In their turn the predacious and parasitic 



