AN IMPORTANT ENTOMOGENOUS 

 FUNGUS 



H. S. Fawcett 

 (With Plates 28 and 29, Containing 7 Figures) 



In 1896, H. J. Webber discovered a fungus parasite of the 

 citrus whitefly and described its sterile form under the name of 

 "Brown mealy-wing fungus (2)." It is now popularly known 

 by the orange growers of Florida as the Brown fungus " of 

 the whitefly. The spread of this fungus on whitefly larvae, — 



(1) by means of superficial hyphae that spread over the surface 

 of the leaves attacking every whitefly larva in their way, and 



(2) by means of spore-like aggregations of cells that may be 

 carried in the air or by insects, — make this fungus one of the 

 most important parasites of the whitefly! This fungus and the 

 red fungus (Aschersonia Aleyrodis) are being introduced by 

 orange growers into many localities in Florida with the belief 

 that they are the most economic means yet discovered of keeping 

 the whitefly {Aleyrodis Citri) under control. 



Spread of the Fungus by Artificial Means 



Artificial means of spreading this fungus and Aschersonia 

 Aleyrodis have been developed by E. W. Berger, of the Florida 

 Agricultural Experiment Station (12, 13). The two most com- 

 monly used are the leaf-pinning method and the spore-spraying 

 method ; the first consisting in pinning into a citrus tree fungus- 

 bearing leaves in contact with larva-infested leaves ; the second 

 in spraying surfaces of leaves with water contaning the spores 

 of the fungi. The latter method has been taken up quite ex- 

 tensively in some orange groves. This is shown by the fact that 

 at the present time there are men in Florida who make it a 

 regular business to spray whitefly-infested orange trees in this 

 way, getting their siipplies of fungus spores from citrus leaves 

 on which the fungus has previously developed upon whitefly 

 larvae. Whenever the atmospheric conditions are favorable to 



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