548 CITRUS FRUITS AND THEIR CULTURE. 



The Black Fungus. Frequently black incrustations 

 covering the dead bodies of scale insects may be seen on 

 citrus trees. This black substance is a fungous growth. 

 evidently a pyrenomycete, but thus far no spores have 

 been found in it in Florida. It evidently does a great deal 

 toward holding scale insects in check in Florida, and 

 Prof. Earle has also found it in Porto Rico. 



The Red Aschersonia. (Aschersonia aleyrodis Web- 

 ber). This is an extremely important enemy of the White 

 Fly, Aleyrodis citri. It attacks the insect in the pupa 

 stage. An elevated ruby or pinkish pus- 

 tule is formed upon the pupa. This is sur- 



. - 



rounded by a little yellowish or whitish ol fiYv 

 band. As the fungus matures the color v/ j. 1 N ^ 



becomes deep red. In this red portion, the 

 spores (sporules) of the fungus are pro- ^j g - ^- A s s ^ r e e r s 

 duced. These are borne in pits. They are sonia - 



narrow, pointed and frequently curved. Usually they 

 consist of but a single cell. 



The mycelium of the fungus grows and develops in 

 the body of the pupa3, the spore formation taking place 

 after the insect is dead as in other cases. 



The fungus, when once established, spreads quite 

 rapidly through a white-fly-infected grove. Unfortunately, 

 it is not so readily spread, artificially, as the Grey Fungus 

 of scale insects. 



The Brown Fungus. This fungus was first brought 

 to notice by Dr. H. J. Webber, of the United States De 

 partment of Agriculture. It is probably the most effective 

 fungous enemy of the White Fly. 



The fungus forms hard, brown pustules on the pupae 

 of the insects. They are attacked when at rest on the 

 leaves. The fungus having once gained a foothold, spreads 



