CONFEKENCE ON ERUIT GROWING. 



27 



upon the trunk and twigs. Moreover, there is an active migration from 

 roots to trunk and vice versa in the summer and autumn, some remaining 

 above ground, some beneath all the year. We thus see that any treatment 

 we adopt must include both races, or else it will be of only partial success. 



Treatment. — This is best carried out in the autumn after the crop is 

 picked, when a good spraying with strong soft-soap solution will soon 

 destroy the lice. This should be applied to trunk and boughs with rather 

 more than usual force, so as to remove the woolly covering which protects 

 the insects. 



For summer use, quassia and soft soap may be employed. 



The treatment of the aerial form is of little value unless we attack the 

 ground form also, whch can only be done in this country by the injection 

 of bisulphide of carbon into the soil. A moderate-sized tree requires one 

 fluid ounce, half of which should be placed about 6 inches under the 

 soil on each side of the trunk about 2 feet away from it. Great care 

 should be taken not to make the hole, into which the carbon is poured, too 

 near, a root, as actual contact is injurious. The hole should be rapidly 

 closed with clay, so that the fumes all spread out slowly through the soil. 



Lastly I must refer to two varieties of Apple which continue proof 

 against the attack in Australia, viz. the Northern Spy and the Majetin, 

 which are largely used in that country for stocks. 



Other Aphides. — For practical purposes we may place all other orchard 

 aphides under one category, as they affect all fruit trees. We have them 

 smothering Apples, Plums, Cherries, Currants, and Gooseberries. The 

 Pear is, perhaps, least subject to their attack. 



With aphides we have several well-known yet unexplained phenomena : 

 for instance, their strange and sudden appearance, and disappearance. 

 This is partly due to their migratory habits, many kinds living on two 

 different plants during their life-cycle. 



Many of our worst fruit aphides curl up leaves to such an extent that 

 no insecticide will reach them. Such we see in the Plum Aphis 

 (Hyalopterus pruni) and two of our Apple Aphides, and in those which 

 attack Currants and Gooseberries. Aphides which are freely exposed, 

 such as the Mealy Plum Aphis and the Stem Apple Aphis (Aphis fitchii), 

 can be destroyed at any time by soft-soap washes, but leaf-curlers are 

 protected during the greater part of their life. When are the Plum and 

 Apple leaf-curlers freely exposed, so that we can attack them by a contact 

 wash ? 



They are quite unprotected in the early spring and autumn. If we 

 examine the prunes carefully in March we shall find situated in the axils 

 of the buds a dull purplish, fat aphis — the mother queen of the Plum 

 Aphis (Aphis pruni), the parent that will give rise to hordes of young that 

 will curl the leaves later on in the year. Thus if we spray our Plums 

 early we can prevent the Plum Aphis, and, moreover, we kill the Hop 

 Aphis (Phorodon humuli variety) before it migrates to the Hops as the 

 so-called " Fly." 



But with regard to the aphides of the Apple it is different, for the 

 eggs of the three species do not all hatch out at once, and as two at least 

 (A. pomi and A. sorbi) at once commence to curl leaves and get into 

 shelter, washing is only partly successful. One species, A. fitchii, alone is 



