TRICHOGRAMMA INTRODUCTION
Most agricultural plants are attacked at some point during the growing
season by one or more species of Lepidoptera and most agriculturally
important Lepidoptera are moths. Moths are adult insects and they
usually feed on nectar produced by plants and honeydew produced by
certain insects. Moths do not attack plants, but serve only to lay
their eggs. Moth eggs hatch into caterpillars, the juvenile form of
Lepidoptera, and these are the primary forms that damage plants by
feeding on the fruits or foliage. Examples of such caterpillars include
corn earworms, cabbage loopers, codling moth caterpillars, and navel
orangeworms, to name a few.
In years past, caterpillar control was usually achieved by application
of insecticides. However, many insecticides now fail to control these
pests. Excessive use of insecticide has led to resistance or tolerance
to many insecticides by caterpillars and many non-target secondary
pests, such as aphids and spider mites, which then become
uncontrollable primary pests. In addition, public outcry against the
use of insecticides on food crops, and the excessive costs for
producing better insecticides has led to a decline in the insecticide
industry and many of the most effective insecticides are now banned
from use in agriculture. However, a few insecticides are still useful
and acceptable and continue to have a place in agriculture. It is in
the best interest of agriculture to extend the efficacy of our
remaining insecticide arsenal by using these only when absolutely
necessary. New, effective, and acceptable insecticides are available in
ever decreasing numbers - but all is not lost!
THERE IS A BETTER WAY
In many situations, low levels of caterpillars can be maintained at
economically acceptable levels by use of alternative methods of
control. One such method is the augmentative release of commercially
available species of Trichogramma. Trichogramma are tiny wasps that
kill the eggs of Lepidoptera. Trichogramma accomplish this by laying
one or more of their own eggs inside the much larger eggs of
Lepidoptera. The Trichogramma egg hatches into a small larva, which
feeds on the inside of the moth eggs, thereby killing it. After 8-10
days of feeding and developing, an adult Trichogramma wasps chews out
through the shell of the moth egg. It then mates with a Trichogramma of
the opposite sex and begins searching for fresh Lepidoptera eggs in
which to lay it’s own eggs.
LEPIDOPTERA MANAGEMENT
The key to management of Lepidoptera with Trichogramma begins with a
thorough knowledge of the life cycle and behavior of the caterpillar
pest. The grower must know when moths first begin egg laying. Release
of Trichogramma must coincide with this time period. Often the release
period is the same period when insecticides are used for control.
Sometimes, first releases are made prior to that time. Multiple
releases may be necessary during several time periods of a growing
season. Several species of Trichogramma are available. These include T.
pretiosum, T. brassicae and T. platneri. The proper procedure and
frequency of release may vary considerably, depending on the target
caterpillar species, their density, the crop habitat, and the cultural
practices in use.
GETTING STARTED
The first step is to carefully plan your Trichogramma release schedule.
Remember, releases should be started when pest moths first appear.
Control with Trichogramma is not a ‘quick-fix’ solution and is not
recommended for ‘out-of-control’ populations of caterpillars.
We will need to know the number of acres and the species of caterpillar
involved. Then we can help you decide on the best species of
Trichogramma for your situation, the number that should be released per
acre, and the number of releases per season. Little or nothing will be
gained by releasing in only a small part of a larger planting. Moths
will only migrate from the untreated areas into the release area and
the Trichogramma will not be numerous enough to provide effective
control. You will not be able to see the difference without a complete
control program. With the information required above, we will be able
to help you plan a program and the Trichogramma will be shipped to you
automatically. We guarantee the highest quality Trichogramma and
service available.
INSECTICIDES AND TRICHOGRAMMA
Most all insecticides are very harmful to Trichogramma adults. However,
the eggs, larvae, and pupae are afforded some protection from
insecticides by the moth egg shell in which they are enclosed. Even so,
it is not wise to apply insecticides during the time period when
Trichogramma are used. Also, it is important that the grower has a good
understanding about the residual life of all insecticides that may be
used during the growing season. Insecticide should be used only when
caterpillar number are "out of control". Trichogramma should be used to
maintain caterpillars at or below economically important levels. Don’t
forget, aphids, mites, and other secondary pests will be less abundant
when insecticides are not used.
PRODUCT DESCRIPTION
Commercially produced Trichogramma are reared in the eggs of moths that
infest certain stored products. Beneficial Insectary produces
Trichogramma on Ephestia kuehniella, which is a larger host egg
compared to the commonly used Sitotroga cerealella. Stored product moth
eggs containing Trichogramma are black in color. Moth eggs parasitized
by Trichogramma are shipped loose or glued to paper cards (30 x one
inch squares). Cards with moth eggs can be placed on plants or stapled
to the foliage or limbs. Loose eggs can be scattered across plants from
‘salt shakers’.
- Information courtesy of Beneficial Insectary
LOOSE EGGS: Minimum approximately 200,000. $15.60 per 100,000
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Trichogramma - eggs
