INSECTS INJURIOUS TO CONIFERS. 



159 



have comparatively few wireworms, but in the absence of better 

 food these probably feed on humus, especially when young. 



If seedlings are actually attacked, hand-picking is a good 

 remedy when facilitated by the use of potatoes, carrots, or sliced 

 mangold, laid on the ground as a bait and regularly visited. A 

 dressing of rape-cake or mustard-cake, popular in hop-growing, 

 may be tried, but the value of it under these circumstances 

 remains to be proved. Serious injury from wireworm is unlikely 

 to extend beyond the first year of growth. 



Chafee-grubs. 



Chafer-grubs cause most damage in the neighbourhood of 

 woods and coppices of Oak and other deciduous trees, because, 

 though they feed underground on the roots of grass, low plants, 

 and young trees of all kinds, the predilection of the parent chafers 

 for such woods usually causes egg-laying to take place in their 

 vicinity. They do not frequent Conifer woods. At the end of 

 May and in June the females select and dig their way into the 

 lightest available soil for egg-laying ; the attack is consequently 

 worst when Pines are grown in sandy districts. 



The larvae feed at a depth of about three inches on roots, 

 biting away the smaller ones and gnawing the sides of the larger 

 ones, even when half an inch thick. They retire to the depth of 

 a foot or more from October to March, and remain under the soil 

 for just over three years, or longer in a cold climate, changing at 

 the end of larval life to a pupa in a cell situated from one to 

 three feet below the surface. 



The best methods of prevention consist in the encouragement 

 of moles, birds, especially starlings and rooks, and in cleaning 

 the ground by hand-picking when it is being broken up, after- 

 wards surrounding it with a trench to prevent the immigra- 

 tion of larvae from outside. In transplantation, when chafer- 

 attack is dreaded, care should be taken to break up the soil as 

 little as possible, as the female cannot burrow in hard, unbroken 

 ground, and it is better to leave it untouched till after the flight- 

 period is over. The beetles not only require a light soil in which 

 to lay their eggs, but refuse to penetrate through foliage or brush- 

 wood to the ground below. For this reason a shelter-wood is 

 especially valuable in situations and with plants where it can be 

 adopted, and seedlings can be protected by brushwood at the time 



