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The control of this pest is difficult and the cost often greater than 

 the value of the material saved. A careful distinction is drawn 

 between general control and the combating of a serious outbreak. 

 If an outbreak occurs in an isolated plantation and it appears probable 

 from its severity that it will last two or three years, it is best to leave 

 the parasites and natural enemies to do their work, for it seems 

 to be a proven fact that three years is the limit of continued attack. 

 If the beech wood be very large and the defoliation serious, 

 the cost of control is too great, and before it is undertaken, the 

 possibility of obtaining sufficient labour must be considered, for 

 half measures are utterly useless. It is often necessary to incur the 

 expenditure on one wood or plantation in order to save others near 

 by in the following year. Removal of the egg-masses is an important 

 method of control. In German forests the workmen rub them 

 off with the hafts of their mattocks ; the rounded trunks make this 

 difficult to effect properly and many are simply knocked off and fall 

 to the ground. Painting with oil was found more effective, and experi- 

 ment showed that no properly oiled egg ever hatched. The maximum 

 period during wliich the process can be carried out is three weeks and 

 the trunks must be visited several times to make sure that all fresh 

 egg-masses are oiled : many may be out of reach or hidden from view, 

 and though good, this method cannot be regarded as absolutely 

 complete. Killing the caterpillars can be done by sweeping them 

 off the trees at the time w^hen they begin descending to pupate ; 

 short- handled brooms or hard brushes are the best tools. As the 

 caterpillars are very easily disturbed, hitting the trunks with wooden 

 mallets will bring them down in thousands and they may be collected 

 on rick cloths spread on the ground, or may be gathered up with the 

 fallen leaves, though if there be much undergrowth, this plan is 

 difficult to carry out. High-banding of the trunks with sticky material 

 above the level at which the eggs are laid, prevents the caterpillars 

 from reaching the foliage ; and low-banding, at a height of 4 or 5 feet 

 above the ground, will catch any that try to descend and prevent others 

 which may have dropped from the branches from recovering their 

 position. Banding is unfortunately not so effective as might be 

 supposed ; even careful banding at 16 feet above the ground has been 

 found to leave eggs enough higher up to produce sufficient cater- 

 pillars to defoliate the tree. In any case the material used should be 

 such as will remain tacky for two months, and care should be taken 

 that all trees are banded without exception ; the cost of the material 

 for 120 acres of beech wood is very considerable and proper high- 

 banding is obviously an expensive operation, as ladders must be used. 

 Trap and isolation trenches, 12-14 inches deep and 10-12 inches wide, 

 with holes 5 or 6 inches deep at the bottom at intervals of 5 or 6 paces, 

 are useful for preventing the caterpillars after defoliating one tree 

 from travelling to another, or for preventing the invasion of a neigh- 

 bouring plantation. Although the caterpillars do not, as a rule, 

 travel far over the ground, except when driven by hunger, they can 

 and do creep out of the trenches, and these must be therefore cleared 

 daily. The collection of the pupae on the fallen leaves, &c., is probablv 

 one of the best methods of control, but these should not be destroyed 

 at once, but so dealt with that the parasites may escape and multiply. 

 Collection of the insects themselves is regarded as quite practicable 



