FLORIDA STATE HORTICULTURAL SOCIETY. 
83 
method for introducing the fungi during 
the period of summer rains or at other 
periods when abundant whiteflies are in 
the trees. Most excellent results have 
been obtained with the red and yellow 
Aschersonias by pinning fungus-bearing 
leaves during June, July and August. 
The spore-spraying method can be used 
at any time, but it will probably be diffi¬ 
cult to start fungus in winter and early 
spring by any method. There are indi¬ 
cations that larvae of the fourth stage 
and pupae (in which two stages the “fly” 
exists from about December until March 
and April) are not readily, if at all, in¬ 
fected with fungus. 
PLAN OF CAMPAIGN. 
The writer’s plan of campaign, based 
upon experiments in the field, is as fol¬ 
lows:—If a grove is thoroughly infested 
with whitefly, and sufficient “seed-fun¬ 
gus” is available, introduce fungus into 
all the trees; but if the supply of seed- 
fungus is limited, distribute it here and 
there throughout the grove, so that there 
will be a great many centers of infection 
from which the fungus can spread. It 
may be considered advisable to treat only 
a few trees in each row with fungus, and 
it may only be possible to treat some 
branches of each of these trees; but any 
scheme of distribution that will give the 
fungi a good chance to spread to all parts 
of a grove will suffice. Later on, when 
more seed-fungus is available, the trees 
or parts of trees not previously treated 
may be attended to. A second, and even 
a third or fourth treatment may be given 
to the trees in order to get the quickest 
possible dissemination of fungus. So 
long as only a few fungus pustules are 
visible on those leaves of a tree which 
bear the most fungus, it will be advisable 
to introduce more fungus, especially 
should an abundance of seed-fungus be 
readily available. The greater the 
amount of fungus growth which is 
successfully started in a grove by 
artificial means, the more rapid will 
be the destruction of the whitefly. White- 
flies have the habit of congregating on 
water-sprouts and other tender growth 
of citrus, consequently we should give 
particular attention to introducing the 
fungi into such parts of the trees. The 
work should be done methodically and 
not in a haphazard way. 
The plan of campaign for a grove just 
becoming infested with whitefly; or only 
infested in part, would be to introduce 
fungus into all those trees sufficiently in¬ 
fested (that is, whitefly by the dozen 
on the leaves), and later on into other 
trees as soon as they become sufficiently 
infested. Incidentally, the trees should 
be fertilized a little more heavily. 
“Seed-fungus” becomes abundant 
about midsummer and lasts until midwin¬ 
ter and later, although some can gener¬ 
ally be obtained somewhere at all times. 
The best weather conditions for intro¬ 
ducing fungus are met with from about 
June to the end of August. Since the 
period of summer rains is also the time 
when “seed-fungus” is abundant it is 
about the best time in which to introduce 
fungus. It is advisable, however, to in¬ 
troduce fungus at other times when “seed- 
fungus” is available, using onffi the spore¬ 
spraying method when young larvae are 
abundant and adults not ^ plentiful 
but employing either one of the 
two methods (spore-spraying or leaf- 
pinning) during the warmer months, or 
when adult “flies” are swarming abun¬ 
dantly about the trees. It will, of course, 
be evident from a perusal of the preced¬ 
ing pages that it would probably be use¬ 
less to try to introduce fungus from 
