THE EED FUNGUS. 21 
valuable data on cultural methods and on the introduction of arti- 
ficially grown spores. Dr. George F. Atkinson, of Cornell Univer- 
sity, was successful in growing cultures of this fungus during the 
summer and fall of 1907 from material sent him by Mr. Worsham, at 
that time an agent of this bureau, and under date of September 30, 
1907, sent the authors at the Orlando Laboratory cultures from 
which infections were secured in the grove. 
DESCRIPTION. 
A glance at Plate I, middle figure, would give one unfamiliar with 
this fungus a sufficiently correct idea of its appearance and make 
possible its identification in the grove. (See also Plates III and IV.) 
Dr. Webber's original technical description is as follows: 1 
Stroma hypophyllous, depressed hemispherical, pinkish buff or cream colored, 
coriaceous, l-2|mm. in diameter; mycelial hypothallus grayish white, forming a thin 
membrane closely adhering to the leaf and extending about 1 mm. beyond the stroma; 
perithecia membranaceous, at first superficial, later becoming irregular, reniform or 
orbicular in mature specimens, and opening by small, round, or elliptical pores or 
slits; basidia crowded, filiform, slender, continuous, 28-40/z long, 0.94-1. 5a in diam- 
eter; paraphyses abundant, slender, projecting beyond the basidia, 65-100/1 long, 
f-l/z in diameter; sporules fusiform, continuous, mucilaginous, hyaline, sometimes 
obscurely 3-4 guttulate, 9.4-14. 1/jl long by 0.94-1.88/x wide, very abundant and erum- 
pent, forming conspicuous coral-red or rufous masses. (Parasitic on Aleyrodes citri 
R. & H., infesting citrus leaves in Florida.) 
Dr. Webber further states that peculiar darkened cells occur at 
irregular intervals in the paraphyses which are quite characteristic of 
this species of fungus. 
DEVELOPMENT. 
If in the process of dissemination the spores find a favorable resting 
place and the weather conditions permit, they soon germinate or 
grow by sending out rootlike processes known technically as hyphse 
or mycelial threads. Should one of these succeed in finding a vul- 
nerable spot in a white-fly larva or pupa, the growth of the fungus 
becomes very rapid and the insect is soon killed. The following 
description of the development of the fungus within the insect has 
been taken, with slight changes, from that of Dr. H. J. Webber, 2 
which in the main has been verified by the authors. 
The first indication of the effect of the fungus on the larva of the 
white fly is the appearance of slightly opaque, yellowish spots, usu- 
ally near the edge of the larva. In the early stages of infection the 
larva becomes noticeably swollen and appears to secrete a greater 
abundance of honeydew than normally. As the fungus develops, 
the internal organs of the larva appear to contract away from the 
margin, leaving a narrow circle, which then becomes filled with the 
i Bui. 13, Div. Veg. Pliys. and Path., U. S. Dept. Agr., p. 21, 1897. 2 Idem, pp. 23-24, 1897. 
