4 E. A. ORMEROD — PEEVENTION' OF INSECT-rNJUEY. 



by clearing off hairy larvae ; and many others would probably be 

 utilized much more if we had some short account to show the many 

 amongst us who are not practical Ornithologists the points where 

 they help us, and also in cases of unusually large appearance of 

 birds, as of titmice brought together by aphis-presence, rooks 

 searching for grubs in the pastures, sea-gulls, starlings, or others, 

 how to be able to distinguish between friends and foes, or species 

 which are devoting themselves temporarily to good service. 



Where there is a great amount of insect-attack, or where it may 

 reasonably be supposed that insect-presence is doing harm although 

 unseen, there the aggregation of birds should by all means be 

 protected; but as a general thing the amount to which the insecti- 

 vorous birds should be encouraged and increased beyond the natural 

 balance, is a very difficult subject. It is often overlooked that these 

 insectivora feed on the insect-parasites of our insect-pests as well as 

 on the pests themselves, and consequently kill our allies as well as 

 our enemies. This point is brought forward in the Report of the 

 Agricultural Commission of Ontaiio, a work replete with useful 

 information and suggestion, and deserves serious consideration. 

 Various kinds of parasitic Hymenoptera are of such service in 

 keeping down the caterpillars of various pests, as for instance the 

 maggots of the ichneumon flics which hold the cabbage-butterfly in 

 some sort of check, that their special protection and multiplication 

 is advised ; and not to go too much into detail, we may refer to 

 ladybirds that keep down the aphides, dipterous flies that also 

 serve us, and many other species. All these have their uses, and 

 we should soon feel the want of them. 



Other kinds of insect-feeders have their uses also, such as the 

 mole, the bat, the shrew, and even the squirrel, in destroying the 

 "cased" larvae and pupae of the pine saw-fly; but nevertheless 

 it seems to me that any movement to decidedly increase the number 

 of the insect-destroyers beyond the natural balance is not certainly 

 desirable. 



Of course when attack is present any means of getting rid of it 

 is useful, and a great deal may often be done by working on some 

 one special habit, which may frequently be found to exist in very 

 different kinds of insects, and different stages of their lives. For 

 instance various kinds of beetles, as cockchafers and weevils, also 

 the caterpillars of various kinds of moths and sawflies, fall to the 

 ground if their food-plant is shaken ; and if we look at the large 

 class of injury caused to leafage by these pests, we shall find that 

 much good might be done by simply shaking or gently striking the 

 infested boughs or small trees. 



This is a regular part of German forestry or gardening ; in 

 America "jarring" the trees is equally looked to as a means of 

 getting rid of the pests, and in the case of our vegetable crops also 

 there are agricultural methods of carrying out the plan, and it may 

 safely be advised whenever any plant (or tree of a size to which 

 the plan is applicable) is infested, to try immediately what effect 

 a good shaking, syringing, or careful beating will have in clearing 



