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Special thanks to Dr. Steve
Alm, URI Department of Plant Sciences for providing assistance
with demonstrations
sites, and information and review of this fact sheet.
URI
Master Gardener, Rudi Hempe, collects adult oriental beetles
once each week from these traps (early June to late
August) at the Davisville
Demonstration Site.
About
the Oriental Beetle (white grubs)
Chemical Control
Alternative control of the oriental
beetle: mass trapping and mating disruption
About the Oriental Beetle (white grubs)
The Oriental beetle becomes an adult around
mid-June and generally lays its eggs in July.
The larval stage, known as the grub, does cause considerable
damage to turf grasses and nursery plants. The grubs eat
and destroy the roots of the grass. They are
also found in nursery stock, strawberry beds and some outside potted plants.
The grubs live below the ground within the effective root zone (approximately
1 to 6 inch depth). They can stay active during a mild winter, otherwise, they
usually go deeper into the soil when temperatures are cold.
White grubs exposed after harvesting turfgrass.
The
Oriental Beetle grub population was
at a high enough level at the Davisville
Demonstration Site to warrant
treatment. The majority of samples yielded a population
of
10
grubs per square
foot or more. This "level" is often referred
to as the economic threshhold level
where
there are or will be adverse impact and damage to
the "crop" or landscape plant.
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to top
Chemical Control:
An application of Bayer Advanced Lawn Season-Long Grub Control was applied
to infected lawn areas according to the rate and procedures specified on the
product
label. The label is the law.
This
product contains
a
granular
formulation
of
the
active
ingredient
Imidacloprid,
which
is the same active ingredient used in the Trade name Merit.
Generally, a granular formulation of a chemical pest control product
provides less risk of exposure and losses due to leaching or stormwater
runoff than
other formulations such as sprays.
Drop Spreader |
The granular formulation was applied
using a drop spreader for accurate control. This was
especially important as the product was applied to
lawn areas that are near paved driveways, sidewalks,
and roads. |
This
chemical treatment is effective against the new cycle of
white grubs that hatch after the
July mating period. An
additional alternative control
was also used at these sites to provide a second line of defense. Sampling
for white grub populations occurred again in September 2003 and May
2004.
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Alternative control of the oriental beetle: mass trapping and mating
disruption
One form of alternative chemical control for the oriental beetle is known
as mass trapping and mating disruption. The process involves installing
traps (the style being used
here is known as a catch-can trap) that attract the adult male oriental beetle.
Unlike
Japanese beetles, oriental beetles are not as adept at
flying, so these traps must be installed below ground
so that the top of the funnel (opening of the trap) is
at
ground
level.
The
adult male oriental beetle is attracted to the trap due
to a lure that is placed in the upper portion of
the trap. The lure contains
a natural scent
or
sex pheromone that is emitted by the adult female beetle to attract
the male for mating purposes. In this way, the mating
cycle is being disrupted
or
interfered with.
The
pheromone lure is a small rubber tube-like piece that inserts
within a small hole in the above-ground portion of the
trap.
Other
benefits
Oriental beetles are usually only active during
the evening hours. This trap and lure will
also encourage
the adult male beetles to come out of the
ground during the day, which increases the possibility of bird predation – another
natural form of pest control.
Operation
In trials on golf courses, traps have been effectively placed as much as thirty
feet apart. It is possible that the oriental beetle will be attracted from
as far away as over one hundred feet.
At
our demonstration sites, the traps have been located
within perennial beds adjacent to lawn areas, and
in areas that allowed for the depth
needed
to install the trap below ground. Traps have been placed
in areas that are mostly sunny,
and in areas that hid the traps
from
plain
view where
possible. The beetles were collected
and counted once each week.
The lures are effective for about six weeks--read
the manufacturer instructions. They should
be installed in early-mid June, as the
grubs become adult
beetles.
The traps
must be monitored and emptied
about once per week. The captured beetles can be drowned
in soapy water.
Costs and suppliers
One catch-can trap and lure set can cost about $17.00,
not including shipping. A replacement lure can cost about
$2.50 each. Costs from 2004. They can be ordered through
Great Lakes IPM
10220 Church Road, NE
Vestaburg, Michigan 48891
1 (800) 235-0285; www.greatlakesipm.com
OR
Trece, Inc.
P.O. Box 129
Adair, Oklahoma 74330
(866)
785-1313; www.trece.com
You can also do a web search on Integrated Pest Management
It is important to know exactly what type of beetle you
have. Japanese beetle lures are different, trap placement
will be different, and the result of this method of alternative
pest control is not the same as with the oriental beetle.
For
assistance with pest identification and management:
The
URI Plant Protection Clinic, (401) 874-2900
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