Insect Enemies of Trees 195 



devastations, which are, however, not very deadly, are 

 principally confined to the larch. It is usually known as 

 the " larch blight." 



The Pine Shoot Moths (Eetinia buoliana and E. 

 turionella) would seem to be more numerous in this country 

 than is generally supposed. Quite lately I visited a large 

 plantation of young Scotch fir, the terminal buds of which 

 were greatly injured by the caterpillars of this elaborately- 

 coloured moth. The moth lays its eggs at the base of the 

 buds, and into these the caterpillars enter by hollowing out 

 the centre, thus destroying their vitality and causing them 

 to take on a withered appearance and to feel soft and empty 

 to the touch. Trees infested by this insect resemble greatly 

 in their stunted shoots and exudation of resin such as have 

 become a prey to the Pine beetle (Myelophilus piniperda), 

 only in the latter case it is the fresh young shoot and not the 

 bud that is attacked. The Retinia would seem, from all my 

 notes and observations, to be most abundant in what might 

 be termed neglected fir plantations, that is, where the trees 

 have suffered from overcrowding, or from unfavourable 

 conditions as to soil, etc., and particularly when the wood 

 is composed entirely of one species. There is no method of 

 dealing with large infested areas, for the attacked trees 

 have repeatedly been cut over and removed without any 

 seeming diminution in the numbers of the insect. One 

 experiment with a small infested corner has been rewarded 

 with good results, viz. the lighting of a fire to windward, 

 and causing the smoke of coal tar to pass over the infected 

 area. This might be worth trying in the case of fruit trees 

 infested by particular insects. 



The Larch Miner (Coleophora laricella). Few, other than 

 those specially interested in tree diseases, have the remotest 

 idea that the yellow, withered appearance of many of our 

 English larch plantations is due to the larvae of the above 

 tiny moth. It usually attacks young trees, say, from five to 

 twenty years old, and although it may not kill them out, yet 

 the repeated onslaughts year after year tend to keep the 

 trees in an unhealthy condition, and so render them liable 

 to other and more deadly diseases. 



