Plum Aphis. 



5 li- 



the acid and water, and the box or tent rapidly closed. When 

 opened at the end of an hour, it should be done so that the 

 wind blows the fumes away from the operator, and left to 

 ventilate for half an hour before the stock is removed 



Plum Aphis. 

 {Aphis pruni, Reaum). 

 This is one of the most destructive plum pests, and was 

 unusually abundant in 190J, complaints being received from all 

 parts of the country. The attack is very characteristic ; the 

 leaves shrivel up, the edges being gradually rolled up and 

 forming nests for the rapidly increasing insects ; the fruitlets 

 soon commence to fall, and the leaves die right off. During 

 last season it was observed that the young leaves that were 

 attacked fell prematurely when still green, but as a rule they 

 hang on, and the tree presents a strikingly characteristic 

 appearance. 



Damson plantations often suffer most severely from this 

 blight. A good show of blossom may be seen in May, and by 

 June scarcely a fruitlet or leaf will be seen on the trees. Plums 

 of all kinds and greengages suffer nearly as severely. The 

 same aphis may also be seen on peach, apricot, apple, and, 

 according to Buckton, on the aster. It is subject to consider- 

 able variation in size and colour, and probably occurs on other 

 plants, amongst which have been mentioned chrysanthemum 

 and gooseberry. Wild prunes, such as the sloe, afford a constant 

 means of invasion of our plantations. 



This species must not be confused with the hop-damson aphis 

 (Phorodon humuli var. Malaheb), easily distinguished by the 

 frontal tubercles, which are absent in the plum aphis. 



Life History. 



The aphis first makes its appearance in the early spring, when 

 small green lice may be observed here and there on the young 

 leaves. These have come from eggs that have remained all the 

 winter upon the plum trees. These lice rapidly grow into the 

 wingless viviparous females, large green aphides, varying in hue 

 to olive brown ; they have three faint green stripes on the 



