52 



(6) Aphis pomi is a leaf-curling aphis and is common on apple 

 trees. The black, shiny, elongated eggs hatch out in April, and the 

 greeny-yellow larvEe soon commence to attack the newly-opened leaves. 

 After casting their skins three times they develop into viviparous 

 females, which at once produce living young, by a process of " budding," 

 and these soon grow. 



The leaves now curl up, on account of their punctures caused by 

 the piercing proboscis of the aphis. 



About the middle of July the pupal stage is reached, and soon 

 afterwards winged viviparous females appear, which give rise in the 

 autumn to wingless males and females, the latter depositing their eggs 

 in November on the young shoots and in the axils of the twigs. 



c. Aphis sorbi is only very httle understood at present. It migrates 

 from the apple in June or July, returning to it in the autumn. 



The leaves curl up, on account of the punctures made, or bhster, 

 and have a reddish colour. 



The lady-birds and their larvae eat enormous quantities of all 

 these aphides. 



Insecticides. — Winter washing is only partly good in destroying 

 these pests. Also, if you have let the leaf curl up, it is useless and 

 waste of time and labour to spray, as the hquid cannot possibly get 

 to the insects. 



Before the leaf curls up, spray with tobacco water made by 

 steeping 2 lb. of tobacco in 9 gallons of water for several hours. 

 Dilute this when using, adding i gallon of the preparation to 3 

 gallons of water. 



Be sure to spray before the leaves curl. 



Also keep the plantation clear of weeds and clovers, as these are 

 plants the aphides migrate to. 



3. The Apple Sucker, Psylla mali. Order Rhynchota. 



The larva of this insect is very small, being closely concealed in 

 the buds, on account of which its presence is not easily observed. The 

 damage done to the leaf and flower buds is often put down to the 

 work of the aphis, which is about at this time and is much more 

 easily seen than the Psylla. 



This pest has been known in Britain for several years, but it is 

 only just lately it has been recognized as a serious pest. There is 

 an allied species in America called Psylla pyricola, which does 

 a great amount of damage to the pear trees. The perfect 

 insect is seen from the middle of May until the end of June. 

 It is of a green colour with shades of yellow, but the colour varies 

 according to the sex and the time of year. At breeding time the 

 female is distinguished by being more brightly coloured than the male. 

 The wings are transparent, and the legs and antennae are yellow, the 

 latter having two or four dark-coloured joints at the end. The 

 female is about one fifth of an inch long, the male being slightly smaller. 

 The larvae are very small at first, having flat yellow bodies with brown 



