The Florida agriculturist., 1907-12-18

well-knOWn Brown Fungus in color,
though of a more cinnamon brown,
has been observed on whitehy larvae
at various times during the past
two or three years. 1t was first
brought to the writer's notice in the
fall of 1905, by DR.. E. H. Sellards
(then entomologist Of the Florida Ex
pertinent Station), who thought that
it might prove to be the spore-bearlng
stage of the Brown Fungus. The
Brown Fungus, known in Florida
since 1896, had never been observed
in a spore-bearing condition; but this
cinnamon-colored fungus was found
to be producing an abundance Of
spores.
General Description.-At first sight
one might mistake the Cinnamon
Fungus for the Brown Fungus. The
color of the raised, hemispherical
pustules, however, is a cinnamon
brown, and they usually present a
oowdery appearance. UNDER the hand
lens they are seen to be brush-llke i'll
form, bristling with a mass Of CHINA
mon-colored hyphae From the mar
gin Of the cinnamon-colored pustules
there grows out layer Of white inter-
woven threads, which spread for a
little way over the leaf. From these
white threads, as we'll as from the
top of the pustule, there arise upright
stalks, which bear the minute spores.
Experiments With the Fungus
Experiments were begun in 1905, with
the view Of determining whether this
spore-bearing form belonged to the
Brown Fungus, or was another spe-
cies. By transferring spores Of the
Cinnamon Fungus to culture media
in the laboratory, pure growths Of
the fungus were obtained. Spores
from these were transferred to white
fly larvae on orange trees in the
greenhouse, with the result that pus-
tules, identical with those from which
the growth was first started, were
again obtained. These pustules re-
tanned their cinnamon brown powdery
appearance, and were not observed
to change to the smooth, hard form,
so characteristic of the Brown Fun
gus During the past summer the
Cinnamon Fungus has been introduce
ed at several places into whitefy in
fected trees, by the leaf-pinning meth
Cd commonly employed for the Red
and Brown Fungi.
Scientific Name and Relationship
The cinnamon-c -co1ored fungus is a spe-
cies known scientifically as Verticil-
lium heterocladum. As far as is
known, it has not been reported be-
fore as occurring on Whltefy larvae,
or on scale insects, in this country.
Verticillium heterocladum was first
described bv O. PenciZ, about 1887,
as occurring on a soft scale insect
Gecanium) on lemon leaves in Italy.
Several closely related species Of Ver-
t1cillium have been reported in Eu-
rope as occurring on insects; one on
plant lice, and at least two others on
small insect larvae. Recently a Gin
namon-colored fungus, which appears
to be identical with the one on white
fly, was found on a scale insect
(Diaspis), on the strawberry bush or
spindle tree (Eunonymus amer1canus),
in the woods near Gainesville.
Fungi Parasitic on Whitefy.-Thc
addition of the Cinnamon Fungus
swells the list of fungi that are known
to be more or less parasitic on the
whiteAy, to six Species They have
been published as parasitic on the
whitefy in the following order:
R d Aschersonia (Aschersonia
aleyrodes) ;.......>c......... 1893
The Brown Fungus (Spores TN
known ................ 1896
Yellow Aschersonia (Aschersonia
Red-feaded ID fungus (Sphaeros- '''
ti1be cOccODhi1a) 1OOz