THE LARCH LEAF-MINER. 39 



out in from fourteen to twenty days with small reddish-brown 

 larvae. Like other species of the genus, the young larvae at once 

 -commence to tunnel the needles, the ends of which soon become 

 whitish and shrivelled up. Out of this mined portion the larva 

 next forms a case, separating it completely from the needle; this 

 it lines with a silky coat, and, after creeping in, it drags in with it 

 a fresh leaf or needle, to which it attaches it. Here it leaves the 

 .case and again commences to mine the tissues, returning from time 

 to time to the case. After numerous needles have been treated in 

 this manner, the case is attached to the branches or stem of the tree, 

 or in cracks or crevices in the bark, which are favourite places for 

 hibernating in. In such spots as these the larva remains for the 

 winter. A large number undoubtedly die, whilst others are eaten 

 T)y other insects, birds, etc. 



In the following spring the larva returns to the needles, com- 

 mences feeding, and the ends of the needles again become whitish 

 .and shrivelled. By now the larva has almost attained its full 

 size, so that the original case is no longer capable of containing it, 

 in consequence of which it commences to cut along one side and 

 work in a further portion of leaf, thus increasing the dimensions 

 of the case. Towards the end of May or early in June the cases 

 are firmly attached to the needles, and pupation takes place, the 

 moth appearing about the middle of June. 



PREVENTIVE AND REMEDIAL MEASURES. 



From observations made by myself and others, it seems clear 

 that the conditions which most favour the attacks of this moth are 

 the close planting of larch trees and where they are grown in large 

 numbers. Some good may be done by thinning and burning the 

 infected trees. Open growth is another important factor. 



Wherever possible, mixed plantations should be put down, 

 and on the first appearance of attack the lower branches should be 

 cut away and burnt. 



Experiments have been made in gardens with various spray- 

 fluids, and an application of paraffin emulsion or soft soap and 

 water '\ Ib. soft soap and I gallon water) was found effective in 

 preventing the female moths depositing their eggs on the needles. 

 The applications were made during the first week in July. 



THE OAK LEAF ROLLER MOTH. 



Tort7ix viridana, Linn. 



Not for many years past has this insect been so plentiful as 

 during 1905. In certain districts it has swarmed over the trees in 

 myriads, stripping almost every leaf. In one case recorded, the 

 larvae had attacked apple trees adjoining a small plantation of 

 oak trees. Numerous cuttings were sent me from time to time, 

 and the moths were bred. So far as I could discover, the larvae 

 -behaved precisely in the same manner as those on the oak trees. 



