Milford chronicle., 1963-12-13
Killing Fungus Found

| Agricultural scientists at the
University of Delaware have un-
covered a biological phenomenon
that may save soybeanproducers
thousands of dollars each year.
The discovery was revealed at
the 35th annual meeting of the
eastern branch Of the Entomolo-
gical Society of America by DR..
IW. A. Connell, associate pro-
Ifessor of entomology, John A.
Mellott, a graduate fellow in en-
Itomology, and Alan L. Morehart,
Iresearch associate in plant
pathology.
In research conducted at the
University they isolated fungus
that destroys the strawberry
spider mite, costly pest of
Isoybeans and vegetable crops.
The discovery was made last
summer when a serious out
break of these mites was sud-
denly halted. This natural-oc-
Icurring control caused the re-
Isearchers to look for and find
fungus spores that actually de-
stroyed the mites. They were
able to isol ate the fungus and
establish that it was one that
occurs in soybean fields under
unknown circumstances.
So far, according to Morehart,
they have been unable to match
the characteristics of the fungus
with any of the 101 known fungi,
which leads to the possibility that
ii may be a completely new kind.
EntomologiSts were convinced
prior to this find that some
thing had checked other straw
berry mite outbreaks, but no one
had been able to establish the
Killers identity.
Mellott says that in their OBJ
servations the pests had been
controlled by disease caused
by the natural occurring fungus
spores. The disease killed the
mites in various stages of de-
velopmant late in the growing
season, giving almost complete
natural control.
The significance Of this dis
covery is difficult to measure in
dollars and cents, but DR.. Dale
Bray, chairman of the depart
ment of entomology at the Uni
versity Of Delaware, says this
may offer growers an effective
biological control method for
crop pest that up to now has
gone pretty much unchecked. He
says the mites infest thousands
Of acres Of soybeans on the
peninsula each year causing re
duction in yields and beans Of
inferior quality.
According to MellOtt, the mites
attack the leaves in the growing
plants and destroy the chloro-
phyll which is the growth-pro-
ducing substance that allows the
plant to manufacture food. The
results are reduced yields and
seeds that are of inferior quail
ty.
While many miticideS have
been used to control strawberry
spider mites, none have been
particularly effective. The mites
build up SO rapidly that single
application hasn't given the de-
sired control, and additional ap-
plicationS cost more than their
value to the crop.
It is hoped that through the
isolation of this mite killing fun
gus a whole new control tech
nique can be developed. Mellott
believes the fungus might be
produced artificially and the
spores could then be sprayed or
busted on fields where mite
damage is a problem. One ap-
plication might control the mites
during the entire growing season
at low cost.
So far, it hasn't been possible
to produce the fungus under
laboratory conditions but More
hart is working on it. New tech
niques will have to be developed,
he says, before large supplies
necessary in a control program
can be produced artificially.
The scientists all agree that
additional information and test
ing is needed before the real
value of the fungus can be de-
termined, but it does show
promise.
Traditional biological control
methods pit good insects against
bad ones. This doesn't usually
give the degree Of control that
the protection of our food, fiber
and health demands, and it has
been difficult to develop supple
mental pesticides that kill bad
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