-Foraging Around, Lancaster Farming, Saturday, April 20,2002
220
Paul H. Craig
Dauphin County
Forage Agent
Pennsylvania hay produc
ers have developed a very
profitable hay market for
timothy grass hay. Timothy
hay is the favored species of
grass hay for most horse pro
ducers throughout the state
and into neighboring states.
It has been estimated that
there are nearly 175,000 acres
of timothy in Pennsylvania
and 75,000 acres in Mary
land. Recent hay prices
reveal a range of $9O to $l7O
per ton for timothy hay. At
top production levels and
price, timothy can gross
$4OO/acre.
In recent years many timo
thy producers have noted de
creased yields and thinning
stands across southcentral
Pennsylvania. In spring of
2000, the cause was identified
as a new pest in the state, the
cereal rust mite.
Travels across southcen
tral PA revealed that the
problem is widespread and
that most stands of timothy
more than two years old have
some level of infestation of
the mite, commonly, but in
correctly, referred to as the
timothy mite.
Reports from across the
region indicate that the
winter of 2001-2002 was a
very favorable season for de
velopment of the cereal rust
mite. This winter, warmer
than normal conditions and
the lack of snow and ice cover
BUY,
SELL,
TRADE
OR
RENT
THROUGH
THE
CLASSIFIED
ADS
IN
Lancaster
Farming
PHONE:
717-626-1164
OR
717-394-3047
FAX:
717-733-6058
Mon., Tues.,
Wed., Fri.
8 AM to 5 PM
Thurs.
7 AM to 5 PM
Update On Cereal Rust Mites In Timothy
provided the cereal rust mite
an early jump on develop
ment. As a result, agrono
mists are reporting heavy
infestations already this
spring. Before simply loading
up the sprayer and taking
after the pest, timothy pro
ducers should understand
some basic knowledge about
the mites.
Identification
The cereal rust mite is an
extremely small pest, actually
l/16th the size of a spider
mite. These mites cannot be
seen without the use of a 16-
power hand lens or a micro
scope. The mites are shaped
like a grain of rice, soft
bodied, with four legs located
near the head of this critter.
They can move fairly easily
up and down the leaves of the
timothy plant but they prefer
to feed on the youngest tissue
of the plant. They are not
commonly found on other
grass species.
The cereal rust mite feeds
on single cells at the base of
the grooves between the veins
on the timothy leaves. The
mite can be found on other
grasses but does not prefer
these grasses and will move
in search of timothy. The
mite inserts a “needle-like”
mouthpart into the cell and
draws out the cell contents,
leaving a shrunken cell. It
then moves to another cell
and continues feeding. Very
rapidly, the plant displays a
‘‘rolled” characteristic that is
very similar to drought stress.
The tip-off to an infestation is
the droughty symptom in
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point pressure
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costs
April or May when adequate
soil moisture is available.
Severe mite infestations
have two negative impacts on
timothy producers.
First, severe feeding causes
substantial yield losses. Yield
loss estimates range from 30
to 70 percent. Severe feeding
has resulted in stressed
stands that are not able to
endure extreme summer
growing conditions, espe
cially droughts and high tem
peratures.
A second impact of the
mite is related to forage qual
ity. Under high mite pres
sures, this hay cures with a
brownish discoloration. This
off color makes horse produc
ers reluctant to pay top
dollar.
History
In the mid 19905, this pest
was first brought to the atten
tion of forage researchers at
the University of Maryland.
Entomologists Galen Dively
and Terry Patton quickly
noted the widespread occur
rence in western Maryland
and initiated small research
trials to evaluate control ma
terials and to gain additional
knowledge on the mite. In the
spring of 2000, ag service rep
resentatives in southern
Pennsylvania informed mem
bers of the Capital Region
Extension Agronomy Team
of the possible spread of this
pest into the state.
In travels across the
region, the pest has been
noted from western Franklin
County to eastern Pennsylva
nia and north to Tioga
County. It has also been
noted in southern New Jersey
and Delaware.
Unlike most crop pests, the
cereal rust mite prefers colder
conditions to summer
weather. The mites
overwinter in the crown area
of timothy plants as adults
and eggs. Maryland has
recorded breeding activity as
early as January. Each
female can lay 20 to 30 eggs
that rapidly reach maturity
in 16-18 days. As a result, po
pulations can rapidly in
crease. Eggs and young larva
are found on the higher
leaves. Adults move down
into the plant crown where
they prefer to feed on the
youngest growth.
As the mites mature, they
will move out and then
“stand up” on their tails and
are dispersed by winds. The
mites have such a great pref
erence for timothy that if
they land on a different spe
cies of plant, they will stand
up and move again. By mid-
April, mite populations are
rapidly building. By May,
signs of heavy feeding can be
noted by looking for the
curled or draughted charac
teristic. When'summer tem
peratures arrive, the mite
enters a dormancy period
and is rarely observed on re
growth.
Growers of timothy should
begin to monitor their stands
of timothy for this pest.
Scouting procedures have not
been fully developed, but pro-
Biology
Scouting
ducers can collect representa
tive samples from across their
field.
Hand lenses are available
from most camera stores or
mail order catalogs. A mini
mum magnification power of
20 is recommended. Costs for
a good lens is less than $25.
Look for the mite on the
surface side of the leaf. Im
mature and adult mites are
similar in shape, like a rice
kernel. In many instances,
eggs can be seen. The egg
resembles an extremely
small, round ball, and will be
evident across the leaf sur
face. Most mites and eggs will
be seen between the veins on
the leaf. Remember that be
cause of population dynam
ics, a few mites can rapidly
develop into an economic
problem. If you do not have
access to a hand lens, look for
curled leaves. Some curled
leaves were evident in fields
with low soil moistures. Since
the recent rains, curling is no
longer as evident on these
smaller plants.
Controls
There are no “natural” en
emies of this pest, primarily
due to the fact that it devel
ops during the winter time
and is dormant during the
summer. Plant resistance is
the long term solution, hope
fully.
A supplemental label use
was granted for Pennsylvania
timothy producers to use
Sevin XLR as a temporary
solution for the cereal rust
mite in 2001. This approval
(Turn to Page 21)
Contact your local
dealer for details.
Pennsylvania
ADAMSTOWN
Adamstown Equip. Inc
717-484-4391
ALLENTOWN
Lehigh Ag Equipment
610-398-2553
BECHTELSVILLE
Miller Equip. Co
610-845-2911
CRESSON & BELLWOOD
Hines Equipment Co.
814-886-4183
814-742-8171
LEBANON
Umberger’s of Fontana
717-867-5161
OAKLAND MILLS
Peoples Sales & Service
717-436-2735
OLEY
Pikeville Equipment. Inc
610-987-6277
OAKLAND MILLS
Peoples Sales & Service
717-436-2735
QUARRYVILLE
Grumelli Farm Service
717-786-7318
TAMAQUA
Charles Snyder, Inc
570-386-5945
Maryland |
RISING SUN
Ag Industrial Equipment
410-658-5568
New Jersey
ELMER
Pole Tavern Equip.
Sales Corp.
856-358-2880