1907.] Ox^CHARD AND BuSH FrUIT PeSTS. 



lays its eggs on the prunes in autumn, and that from the eggs 

 in the early spring, before the buds burst, dull purplish wingless 

 females appear and produce green young (lice), and it is these 

 lice that at once commence to curl the delicate leaves as they 

 unfold. The remedy is obvious, namely, an early washing 

 with soft soap and quassia, to kill the purple viviparous female 

 before the advent of the green lice. These females have been 

 observed to be very sedentary, and remain fixed under a bud 

 and protected by it to some extent. The trees must be ivasJied 

 not sprayed. Two trees were treated last spring, both with the 

 same soft soap and quassia wash ; one was drenched, the other 

 finely sprayed. The former was not leaf-curled at all, while 

 the Idtter showed a considerable amount of aphis ; both were 

 inhabited by this insect. 



Where this aphis goes in the summer we do not know. It 

 certainly leaves the prunes for some other host-plant, as many 

 aphides are known to do. This migration has given rise to the 

 statement that spraying has killed them, the cast skins of the 

 pupcTe being taken for dead insects. 



Mealy Plicui Aphis. — Another aphis is very abundant in 

 Worcestershire, but many growers tell me they do not consider 

 it very harmful. This is the mealy plum aphis {Hyalopterns 

 pruni), which does not curl the leaves but loads them on 

 the under surface until they become mealy masses of insect life. 

 Copious honey dew is formed, and this falls on the fruit. In 

 plantations visited last year where any plums did occur they 

 were often seen to be spoiled for market by the black fungoid 

 growth that follows the sticky honey dew. It occurred in some 

 numbers in Herefordshire and also in Devon. In Kentish 

 orchards it was not so bad, occurring only in a few areas and 

 never seriously. ' All growers seem to have found a difficulty in 

 killing this aphis.. All the washes I have tried have signally 

 failed in doing their work. Whilst in Herefordshire this summer, 

 however, Mr. Getting informed me that he had found that by 

 adding liver of sulphur to the soft soap wash they were all 

 destroyed ; in his plantations they were to be seen alLbrowned 

 and dead. On reaching home I tried this wash, and for the first 

 time was able to kill the aphis at once. Francis Walker stated 

 that this aphis comes from rushes and is the same as Hyalop- 



