JAMES BURTON ON A SPECIES OF ALEURODES. 13 



green flies on very many kinds of trees and shrubs. In the 

 autumn the lower leaves of limes, oaks and shrubs growing 

 under them may be seen to be covered with a black soot-like 

 deposit, which upon examination proves to be a fungus. It is 

 opaque and of course obstructs the influence of the light on the 

 chlorophyll in those leaves on which it appears. Oranges which 

 usually arrive in this country in the spring are often covered 

 with a black deposit near the remains of the flower ; this is some 

 species of Meliola or Capnodium, fungi which flourish on the 

 excrement and secretion of the Scale-insects and no doubt of 

 Aleurodes also. 



In a book published last spring, Insects and Man^ there is a long 

 account of almost heroic efforts which have been made to reduce 

 the loss caused to the Citrus growers of Florida by the depreda- 

 tions of Aleurodes citri, and the injury caused by the fungus which 

 almost always develops on the honey-dew secreted by the fly. 

 It is there stated that " the fungus does more harm to the plants 

 than the insects themselves, pervading, as it does, not only 

 the leaves, but the branches and even the fruit itself. More 

 than 45 per cent, of the Citrus groves of Florida are infested with 

 the fly, estimated to cause a loss of from 45 per cent, to 50 per 

 cent, of the value of an orange crop." 



From experience obtained in other cases it was determined to 

 endeavour to find some insect, such as an ichneumon fly, or some 

 species of lady-bird, which would prey upon the Aleurodes. The 

 American Congress made a special grant towards a world-wide 

 search. At last the commissioners found in India a small reddish- 

 brown lady-bird about one-tenth of an inch long, and also a minute 

 hymenopterous parasite, both of which preyed upon the Aleurodes. 

 Efforts were made to get a supply of these foes upon the scene, but, 

 notwithstanding every endeavour, some difficulty always arose 

 which rendered it unsuccessful. Wardian cases were made in 

 which to bring over young citrus trees, with the Aleurodes fly upon 

 them, infested with the parasite ; and also the lady-birds from 



