INSECTS AND DISEASES INJUBIOUS TO FOREST TREES. 



liooper Moth (ffybernia defolaria). The caterpillars of both 

 these moths are very destructive to the leaves of elms, limes, 

 and willows, but particularly to the buds of the apple tree. 



When full grown they descend to the ground, where they 

 cover themselves and become chrysalides, from which the 

 moths appear from October to December. 



Being almost wingless, it is by no means difficult to pre- 

 vent their ascending the trees by painting a band of any 

 sticky substance around the stems of the trees that it is 

 expected they might attempt to crawl up. 



The Pine Sawfly (Lophyrus Pini). Fortunately, this 

 insect is not abundant in the British Isles, though on the Con- 

 tinent the damage it does in the pine forests is by no means 

 inconsiderable. The insect may readily be recognised by 

 its wide, flattish body, and usually dark appearance. Having 

 attained to full size in the trees, they form cocoons 

 among the foliage or on the stems, and remain in this 

 condition until the following spring, when, in April or May, 

 the perfect insects make their appearance. The male is 

 considerably smaller than the female, while the full-grown 

 caterpillar, which is of a greenish-yellow colour, with a row 

 of black spots on either side, is about an inch long. The 

 remedial measures are not at all easy, especially when a 

 large number of trees are attacked, but single specimens 

 may be entirely cleared by shaking the caterpillars into 

 a sheet placed beneath the tree. 



The Red Spider (Acarus telarius). In hot and dry sum- 

 mers trees suffer much from this member of the mite family. 

 Limes and poplars, as also many other trees, are greatly 

 injured, the foliage turning to a russety brown colour, and 

 falling off long before the usual time. There are several 

 remedies, such as fumigating and spraying with a solution 

 of soft soap, but none of these are applicable to a plantation 

 of trees, or even a single specimen of large size. 



The Thorn Fly (Aphis Cratcegi) attacks whole hedges or 

 brakes of Quick, especially those in the nursery border ; as 

 a rule, the younger and more healthy plants first fall a 

 prey to its depredations. 



Sponging with tobacco water, or almost any of the pre- 

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