202 Lecaniincs. 



insects from an epidemic fungal disease. The scales shrivel and become 

 covered with a greyish-white fungus, which extends as a delicate filmy fringe all 

 round them {fig. lo). Dr. A. Zimmermann, then of the Botanic Gardens, Buiten- 

 zorg, Java, described this fungus under the provisional name of Cephalosporhcm 

 lecanii in one of the circulars of his department. Dr. Zimmermann informs 

 me that he has been experimenting with this fungus with a view to obtaining a 

 culture that can be applied as a spray, but I have not yet heard whether 

 success has attended his attempts. In Ceylon the fungus seems to be widely 

 distributed, but depends upon climatic conditions for its proper development. 

 It appears to be readily communicable by direct contagion in Ceylon. But 

 material sent to Mr. Newport, in Southern India, failed to induce the disease in 

 ' Green Bug' there. The weather in India at the time was not favourable for 

 the experiment. I am inclined to think that this grey fungus has been 

 gradually increasing, and that its effect in reducing the numbers of the bug is 

 more marked year by year. 



Other natural enemies that attack the bug are several species of small 

 ' Ladybird Beetles ' {Coccinellidcx\ and numerous minute chalcid wasps that 

 breed inside the body of the Lecanium. Dr. L. O. Howard, Director of the 

 State Entomological Department, Washington, U.S.A., has identified the 

 following species bred by me from Lecanium viride : Coccophagiis orientalis, 

 How ; Encyrtus flavus, How ; and Ceraptocerus ceylonensis, How. 



But these local parasites of the bug have their own natural enemies, which 

 keep them in check and prevent them from increasing to a sufficient extent to 

 cope with the disease. It was thought that by introducing ladybird beetles 

 from some other country, minus their proper natural enemies, we might succeed 

 in raising up an army capable of fighting this (probably introduced) scale pest 

 on more even terms. This method was adopted with complete success when 

 the Australian beetle, Vedalia cardinalis was naturalised in California, re- 

 sulting in the rapid extermination of the destructive ' Fluted Scale ' {Icerya 

 purchasi. Mask.). Accordingly, living specimens of Exochomus nigropunc/alus, 

 a ladybird known to feed upon allied scale insects, were obtained from the 

 Cape of Good Hope through the good offices of Mr. C. P. Lounsbury, the 

 Government Entomologist of that Colony. These little beetles fed freely 

 upon Lecanium viride in captivity, and multiplied to a certain extent. Their 

 increase was, however, not sufficiently rapid to offer hopes of any practical 

 benefit to be derived from the introduction of this particular species. Small 

 numbers of the beetles were liberated in some of the few remaining coffee 

 districts, but apparently failed to establish themselves. I have also received, 

 through the kindness of Professor W. W. Froggatt, several parcels of 

 Australian ladybirds. Though a few of these survived the journey, I have 

 been unable to breed from them. They fed very sparingly upon such scale- 

 insects as I was able to give them, but died one by one without laying eggs. 

 My experiments in this direction have so far failed, but this may be due to the 

 fact that I have not yet found the proper species to suit the particular 

 conditions. It is hoped that other efforts may eventually prove more 

 successful. 



From the sudden appearance of the pest and its rapid extension, it is 

 almost certain that the insect is an introduced species, and it seems probable 



