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Apple and Pear
Biological Control PO Box 1555, Ventura, CA 93002 800-248-2847 *
805-643-5407 fax 805-643-6267 questions bugnet@rinconvitova.com orders orderdesk@rinconvitova.com web
www. rinconvitova.com |
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A successful IPM program in
orchards will utilize many cultural practices such as proper irrigation to
maintain leaf temperature, kaolin-clay barriers, mating disruption and
trapping, as well as beneficial insect releases. The following are general guidelines for augmenting insect
diversity to control the common pests found in Washington apple growing
regions. See WSU Tree Fruit Research
and Extension Center for complete management strategy.
Mite Control:
The western predatory
mite, Galendromus occidentalis, is ideal as it is a predator of all
common mite pests in orchards, tolerant of hot, dry conditions, and resistant
to many pesticides (contact us with compatibility questions). Release 2,500-5,000 per acre early in the
season at the first sign of spider mites using the presence-absence sampling
method. Continue sampling and repeat in
1-2 months if control is not achieved.
For hot spots, use the Spider
Mite Destroyer ladybeetle, Stethorus punctum. It has been effective in controlling mites in
Pennsylvania apple orchards and released in raspberries and hops in central
Oregon with good results. Release 20
Stethorus per infected tree in hot spots.
They will remain in the trees as long as mites are present, and then
move into the environment. If mites
return, they will follow them back into the trees. Green lacewing (see below) will also aid in mite control.
Aphid Control:
Natural parasites and
predators of aphids are common in organic orchards. Insecticides are detrimental to these and should not be necessary
with an IPM program including monitoring and preventative releases of
beneficial insects.
The aphid predatory midge
Aphidoletes aphidimyza works extremely well in orchards. The larval stage is a general aphid predator
and the adult midge will disperse throughout the orchard laying eggs in areas
of high pest density. Two weekly
introductions of 10,000 per acre will establish for numerous years. They can be generally applied on the
windward side, or, even better, 5,000 applied generally on the windward side,
at dusk, and the rest applied in effected trees.
Green lacewing, Chrysoperla carnea and C. rufilabris,
larvae are general predators that will eat 200 aphids or pest eggs during
their two-week larval stage. The adults
feed on pollen and nectar, and have great dispersal ability. Female adults will lay hundreds of eggs
close to sources of prey for the larvae.
Repeated releases, ant control, and providing food sources for
the adults are critical for successful implementation of lacewing in an IPM
program. Use at a rate of 5,000-10,000
per acre every two weeks for 2-4 releases or until control is achieved.
Cover cropping with corn, sudan grass, and beneficial ‘insectary’
plantings will greatly enhance biological control by forming banks of
parasitized aphids and nectar food sources for the adult predators.
Codling moth:
The lepidoteran egg parasite
Trichogramma platneri is a U.S. native recommended for
western trees. Release 100,000 per acre
for three consecutive weeks as soon as moths are detected in traps. Can be used in conjunction with a mating
disruption program.
For larval control, use
Cyd-X granulovirus, spinosad or Bt sprays timed according to moth flight and
degree-day calculations.
Leafroller:
Conservation of natural
enemy complexes is the critical factor in controlling leafroller
populations. Many natural occurring
parasites attack this pest. Green
lacewing releases are beneficial and the use of non-disruptive pesticides
such as Bt or spinosad.
Thrips:
Thrips are controlled by
conserving natural predators and augmenting with releases of the general
predator green lacewing as described before.
The keys to effective
biological control are starting early and regular monitoring.