43 



ON SOME INJURIOUS INSECTS. 



By W. Saunders, London, Ontario. 



The Codling 'Motu {Carpocapsa poinonella, Litm). 

 The Pear Tree Slug (Selaiidria cerasi, Peck). 



The Codling Moth {Uarpocapsa pommella, Linn). 



This is, indeed, one of th; most troublesome insects with which we have to contend, and 

 one of the most difficult to deal with, and, although of foreign introduction, has spread 

 over the greater part of our country entailing a yearly loss on our apple crop which it would 

 be difficult to over estimate. We shall briefly give the various features in its life history with 

 a cut illustrating the insect as it appears in its various stages, and then detail such measures 

 as have been suggested with a view to its destruction. 



*''«• 2^- Fig. 35 represents a section of an apple which has 



been occupied by a codling worm —h shews the point 

 of entrance of the young worm, the place of exit of 

 the matured larva being shown at the left hand side of 

 the figure ; e, the full-grown worm : /(, its head and first 

 segment magnified ; i, the cocoon ; d, the pupa re- 

 moved from the cocoon ; /, the moth with wings 

 closed ; q, the same with wings expanded. 



Soon after it leaves the fruit in the fall, the 

 larva selects some secluded of nook or cranny, un- 

 der loose bark of tree or other convenient hiding 

 place, and there spins its tough papcry-lookiug cocoon, 

 and within this secure retreat it remains in the lar- 

 val condition until early in spring, when, a few weeks 

 before tbefinal change takes place, it enters the chrysalis 

 state. It seems strange that this tiny creature should 

 be endowed with such a power of varying the length 

 of its larval existence, that at this season the larva 

 should remain so long unchanged, while, in the case of the earlier summer brood, the change 

 to chrysalis takes place almost immediately after the spinning of the cocoon. About the 

 time of the opening of the apple blossoms this insect bursts its prison house and appears as a 

 winged moth. See Fig. 35, g. 



The moth deposits her eggs singly, and usually in the calyx or eye, just as the young 

 apple is forming. In about a week the larva is hatched, and at once the tiny worm begins 

 to eat its way through the apple to the core. Its castings are commonly pushed out through the 

 hole by which it has entered, which is from time to time enlarged for the purpose ; the.se usually 

 adhere to the apple, so that, before the worm is full grown, infested fruit may generally be 

 detected by the mass of reddish-brown exuviae protruding from tiic eye. Sometimes, as the 

 larva approaches maturity, it eats a passage through the apple at the side, and out of this 

 opening its castings are thrust, and here the mature worm escapes when full grown. The 

 occupied apple generally falls prematurely to the ground, sometimes with the worm in it, but 



