No. 5.] De&cfiptwn of a new Pear-tree Aphis from Ceylon. 2'j !^ 



THE PEAR-TREE APHIS, 



LacJinus pyri, Buckton. 



By G. B. buckton, F.R.S., etc. ; with introductory note by 



E. E. GREEN, F.E.S., Honorary Comuliing 



Entomologist to the Government of Ceylon. 



Plate No* XVI. 



In March of the present year (1898) I was requested to examine and 

 report upon specimens of a blight that was said to be attacking cultivated 

 Pear-trees in the Muvara Eliya district of Ceylon. I was subsequently able 

 to observe the insect in sitA. It proved to be a large species of Aphis 

 occurring in large groups upon the stems and branches of the trees,— always, 

 apparently, upon the ripe wood. Where possible, the insects were massed 

 upon the lower or sheltered side ; but they were present in such large numbers 

 that they frequently covered the whole surface of the stem. They secreted 

 an abundant supply of ' honey-dew ' ; so much, that it collected into large 

 drops which ran down the stems and covered the adjacent leaves, attracting 

 numerous flies and other insects. I did not, however, notice any ants in 

 attendance upon this species. Nor were there any larvae of Syrphiis flies 

 preying upon them at the time. In places where the pest had taken complete 

 possession, they seemed to have cut off the supply of sap, with the result 

 that the ends of such branches presented a very sickly appearance, and in 

 some cases died back. 



Female insects in all stages were present, though the winged adults were 

 comparatively scarce. No males could be found. No eggs were observed 

 though the young larvae were very abundant. It is therefore probable that 

 the insect is viviparous. 



If left unchecked this pest is likely to considerably weaken the trees. 

 But, being confined to the stems and branches, it can be very easily destroyed 

 by the use of any insecticide, such as one of the soapy emulsions, applied 

 with a large brush. Plain soap and water, applied very hot, is almost equally 

 effective, and would not injure the tree unless applied to the more tender 

 shoots. The pest may also be kept in check by crushing them with the 

 hand — or a piece of coarse sacking — on the first appearance of the colonies. 



