82 Commercial Gardening 



on the trees, under rough bark and grafting clay in the wingless female 

 condition above ground, and also as wingless females below ground and 

 on the roots near the butt of the trees. Now and again an autumnal 

 sexual brood occurs, the oviparous female laying a single egg near the 

 base of the tree, and her dried skin remains behind as a covering over it. 



TREATMENT. Spraying with paraffin emulsion will destroy the aphis 

 in summer and autumn above ground, but the washing must be done 

 with force; a strong jet must be sent to hit the patches of aphis in the 

 crevices. There is an intimate connection between the Woolly Aphis and 

 canker (see p. 89). 



The ground form may be attacked by injecting disulphide of carbon 

 into the soil, oz. on four sides of the tree about 2 ft. from the trunk 

 and about 6 in. deep, or the earth may be cleared away for 3 ft. around 

 the trunk and the ground soaked with warm paraffin emulsion. In 

 Australia, &c., it is found that the root form does not occur on " Northern 

 Spy" or " Winter Majetin". 



Apple Aphides. At least three species of Aphis attack the Apple: 

 (1) the Leaf -curling Aphis (Aphis ponii); (2) the Rose Leaf -curler 

 (Aphis sorbi)] and (3) the Green-shoot Aphis (Aphis fitchii). 



The former is by far the worst Apple species and is said to live 

 solely on apple. The black eggs are found in masses in winter on 

 the year's growth of wood. In spring they hatch into small lice which 

 spread out over the leaves. Soon they grow into wingless viviparous 

 females of a slaty and mealy appearance, and these produce quantities 

 of living young, which very soon are mature and ready to produce 

 others. These wingless aphides cause the leaves to curl up and fall off, 

 and as they also puncture the shoots the latter become deformed. Later 

 in the summer winged broods appear and fly off. In autumn, about the 

 beginning of October, they return and produce yellowish young, which 

 become oviparous females and lay the ova on the shoots. 



The Rose Leaf Aphis causes the curled leaves to become bright red 

 and yellow. This species also lives on Hawthorn. The Stem Aphis is 

 green and does not curl the leaves, mainly collecting in early summer 

 on the shoots and below the leaves and in the blossom. It migrates 

 between the Apple and various grasses. 



Ants carry all these aphides from place to place and are always 

 found in company with them. 



Not only does Aphis pomi damage foliage and shoots, but in bad 

 cases the fruit is attacked and deformed. 



TREATMENT consists of heavy washings with soft soap and quassia or 

 nicotine wash. If the former, it must be done before the leaves are 

 much curled, as the wash will not enter the curled foliage; nicotine will, 

 however, penetrate into the crevices and curls. Much good will also 

 be done by heavy spraying with the same in autumn, to kill the egg- 

 laying brood under the leaves. 



All prunings should be burnt in winter, as many eggs are thus destroyed. 



