550 CITRUS FRUITS AND THEIR CULTURE. 



METHODS OF DISSEMINATING THE SPORES OF 

 BENEFICIAL, FUNGI. 



The Red and Grey Fungi may be cultivated artifi- 

 cially in the laboratory and afterwards may be placed on 

 the scales, in the grove. A plan which has succeeded in 

 some cases is to take a twig on which the fungus is pres- 

 ent, and tie it closely in contact with the scales on an af- 

 fected branch. 



During the year 1907, Mr. H. S. Fawcett, of the 

 Florida Experiment Station, succeeded in producing cul- 

 tures of both the Bed Aschersonia and the Brown Fungus, 

 on artificial media, in the laboratory. In the same year 

 Dr. E. W. Berger, of the same institution, successfully 

 demonstrated that the Aschersonia disease of the white 

 fly could be distributed satisfactorily both by spraying 

 the pupa3 with water containing spores of the fungus and 

 by pinning leaves, bearing pupa3 covered by the fungus 

 in a fruiting stage, in contact with the insects on the 

 under side of infected leaves. The most satisfactory 

 results were obtaintd during the rainy season, using about 

 one dozen leaves to a good-sized tree. This plan will 

 doubtless rapidly supersede the older plan of spreading 

 the fungus by planting a small tree, on which it is present 

 on the pupa3, so close to the tree in which it is desired to 

 introduce it, that the branches will interlap and allow 

 the fungus to spread naturally. 



The success which has rewarded the efforts of these 

 two workers marks another step in the successful control 

 of insect foes by means of fungi parasitic upon them. 



Insect Friends. The greatest triumph of modern 

 economic entomology was the control of the cottony 

 cushion scale (Icherya purchasi) by the imported Aus- 

 tralian ladybug, Novius cardinalis. The cottony cushion 

 scale secured a strong foothold in California, and 

 threatened the destruction of the whole citrus industry. 



