26 NATURAL CONTROL OF WHITE PLIES IN FLORIDA. 
in the season by a rank growth of sooty mold (Meliola sp.), but this 
usually occurs after the fungus has ceased spreading rapidly and on 
pustules the majority of which would fall from the leaves before 
spring. On the whole these two fungi are of no practical importance 
in checking the spread of the red Aschersonia or in reducing its 
efficacy. 
THE YELLOW FUNGUS. 
(Aschersonia flavo-citrina P. Henn.) 
Specimens of a white-fly parasite from the grove of Mr. J. F. 
Adams, of Winter Park, Fla., sent to Mrs. Flora W. Patterson, 
Mycologist of the United States Department of Agriculture, in Sep- 
tember, 1906, by Prof. P. H. Kolfs, director of the Florida Agricul- 
tural Experiment Station, were identified by Mrs. Patterson as the 
yellow fungus (Aschersonia flavo-citrina) . Previously this had been 
discovered occurring on leaves of the guava (Psidium) at Sao Paulo, 
Brazil, in October, 1901, and described in 1902 by P. Hennigs. No 
insect was mentioned associated with it on the guava leaves. 
Since its discovery in Florida as a parasite of Aleyrodes nubifera 
and A. citri it has been found in several new localities and has been 
introduced into others. Reports and bulletins of the Florida Agri- 
cultural Experiment Station and the Transactions of the Florida 
Horticultural Society contain the only references to data concerning 
the yellow fungus as a parasite of white flies. Prof. Fawcett has 
published the most important contributions to our more technical 
knowledge and has successfully grown artificial cultures on various 
media. Prof. George F. Atkinson, of Cornell University, has also 
successfully grown cultures from which infection has been secured 
in the grove by the junior author in early October, 1907. 
DESCRIPTION. 
The yellow Aschersonia in general form closely resembles the red 
Aschersonia, but is at once separated from it by the rich yellow 
instead of pink or red color of its well-developed pustules. A suffi- 
ciently clear idea of its appearance may be had by referring to Plate I, 
upper figure. (See also Plates V and VII.) During the early stages of 
infection it is impossible to separate these two fungi by ordinary exami- 
nation ; it is only after the pycnidia, with their characteristically col- 
ored spore masses, are formed that they can be readily distinguished. 
Prof. H. S. Fawcett states * that the pustules of A. aleyrodis under 
similar conditions average less in diameter, that the pycnidial cavities 
1 Fungi parasitic upon Aleyrodes citri, University of State of Florida, Special Studies, No. 1. 
