The Florida agriculturist., 1908-03-01

generally well KNOWN among the ClCTuS
growers of this state that there are
several fungi which live parasitically
upon the immature stages (the larvae
and pupae) of the whitefy (Aleyrodes
citri) and that, as these fungi become
we'll established in a grove infested by
whitehies, they destroy these insects
by the million The best known Of
these fungi are the Red Fungus, the
Yellow Fungus and the Brown
Fungus. Three others not so we'll
known are the Red-Headed Scale Fun
gus, the White-fringe Fungus, and
the Cinnamon Fungus The last
two have only recently been de-
scribed by Prof. H. S. Fawcett, OF
this Station, in Press Bulletins 68 and
70 respectively; and their discovery be-
ing relatively recent we are not so we'll
prepared to make recommendations,
either as to their efficiency in reducing
the whitehy, or as to the best methods
for introducing them. The Red-headed
Scale Fungus, so efficient in reducing
scale insects in Florida, has only rare
1y been observed upon any of the young
stages of the whitehy, and so will
receive no further mention here.
Preparation of Spore- Containing
Liquid.-The following description Of
the spore-spraying method for intro
ducing the fungi is based mainly upon
experiments with the Red and the
Yellow Fungi and the method was ap
parently first successfully employed by
the writer. 1t is considered the prefer
able method, and is probably applica-
bic to all the fungi mentioned, except
ing perhaps the Brown Fungus. EK-
periments so far indicate that tffiN
method can be employed during any.
month of the year, although betters
infection with fungus may generally
be expected during the warmer months.
The spores or germs (Which take the
place of seeds in fungi) are washed out
of the fungus by means of water.
Use about forty of the bright red or
bright yellow pustules of the fungus to
a pint of water. This will be about the
same as one or two fungus-bearing
leaves to a quart of water. More tun-
gus may be used, but the amount indi-
Gated has been found to give good re-
suits. Soak and wash the fungus
Qeaves and alp for ten or fifteen
A1inutes, and strain through cheese
cloth or fine wire gauZe.
Spraying and Sprayers.-Spray the
mixture of spores and water on the
under surface of the whitehy-lnfested
leaves. Look we'll to the newer
growth, and if the larvae and pupae, Or
the adult flies, or all three, are abund-
ant there, spray the parts thoroughly.
If the supply of seed-fungus is limited,
inf
and branches, for the fungus will in
feet some of the larvae there, and the
adults maturing from those not infect
ed, together with other adults migrat-
ing there, will carry the fungus spores
to other parts of the tree and to other
trees. Use a new spraying outfit,
preferably one of the Compressed Air
Sprayer type 6 or 4 gallons capacity,
with little or no copper or brass about
it. Do not use an outfit previously
used for spraying Bordeaux or other
strong fungicide, since the small
amount of fungicide left in the machine
may kill the spores. An old spraying
outfit which has been previously used
only for soap solutions or oil emul-
sions may be employed, but it should
be we'll washed out with water A
larger spraying machine mounted on a
barrel may be used when many acres
of trees are to be sprayed, and when
an abundance of fungus is available.
Use a nozzle producing a very fine
spray, and thoroughly wet the leaves
just to the dripping point It requires
about three weeks for the Red and
Yellow Fungi to make visible growth.
A modification of the spore-spraying
method, recently brought to the