22 NATURAL CONTROL OF WHITE FLIES IN FLORIDA. 
hyphae or mycelium. This circle becomes opaque and whitish, 
presenting a very characteristic appearance. Shortly after this 
the hyphae burst out around the edge of the larva, forming a dense 
marginal fringe. This may form all around the larva at about the 
same time, or may develop at one portion of the margin sooner than 
at the others. The body of the larva at this time is plainly visible, 
but it is opaque and yellowish throughout. Death usually ensues, 
it is believed, before the hyphae burst out. The fungus does not 
spread over the leaf to any great extent, but grows upward in a mass, 
gradually spreading over the larva. It is not uncommon to find the 
perithecia, with their bright coral-red masses of sporules, formed in a 
circle around the edge of the larva while it is yet visible. As the 
Aschersonia develops, the hyphae spread over the larva, forming a 
dense, compact stroma, which ultimately entirely envelops the 
larva. The stroma in this stage is thin and disklike, the fructifica- 
tions being^ usually borne in a circle near the edge. The hymenium 
at this time is spread out on the surface of the stroma, or but slightly 
sunken, the sporules projecting in a conical coral-red or rufous mass. 
As the fungus develops the stroma becomes thickened and hemi- 
spherical and the hymenium gradually becomes immersed. The 
hyphae which make up the main mass of the stroma are from 3.5 to 
7.5 micro millimeters in diameter. Within the body of the insect 
and near the perithecia they are somewhat smaller. 
Data collected in connection with experimental work in the field 
have shown that well-developed pustules can mature within 15 days 
after artificial spreading of the infection. Ten shoots on the outside 
of a tree which were sprayed on June 25, 1909, had developed by 
July 10 numerous well-developed pustules (red Aschersonia). Check 
shoots produced no fungus growth. The range in temperature 
during this period was from 70° to 95° F. (average daily mean, 80.5° 
F.) and frequent showers fell. Fungus introduced by spraying on 
July 27, 1907, had produced pustules by August 17, or 21 days later. 
During this period the temperature ranged from 70° to 98° F. 
(average daily mean for period 80.8° F.), with numerous showers. 
In both of these instances no earlier examinations were made. In 
another instance a larva of A. citri, noted to have died on October 15, 
1908, began to develop a whitish appearance on October 23, or 8 
days later, and while the fungous growth was daily observed the 
characteristic reddish color of the spore masses of red Aschersonia 
did not appear until November 4, or 12 days after the fungus first 
began to be visible to the eye and 20 days after the larva was recorded 
as having died. During the 20-day period the temperature ranged 
from 45° to 85° F. (with an average daily mean of 70.4° F.) and there 
was no rain. The average daily mean humidity for the three periods 
was 92.3, 89, and 90 per cent, respectively. 
