cycle: Very prolific. Many generations per
Physical Description: Harmless to
humans and animals. They are less than 1/32 of an inch long, and are
not likely to be seen or collected except as a result of caging parasitized
eggs and observing them with a lens. They are black, brown, or yellow
in color. The wings
are margined with hairs. The greatest width of the body is at its eyes.
The entire immature life is spent within the host egg.
The commercially available Trichogramma Wasps are:
Trichogramma evanescens - Best
used in Orchards
Trichogramma minutum - Best on
trees and in orchards where the protective zone is five feet or more
above ground level.
Trichogramma platerni - Best for
avocado groves and orchards.
Trichogramma pretiosum - Best in
vegetable gardens where the protective zone is five feet or less above
Feeding characteristics: These
tiny wasps are parasites
inside the eggs of other insects. They parasitize
eggs on up to 200 insect pests, including the eggs of the following:
They lay one to fifty eggs in single
host egg, which then terminates development. The host egg will turn
black. The larvae
feed on the egg and emerge as an adult. Females normally outnumber
males depending on the availability of food. A European and Australian
species actually swims underwater in order to place their eggs in those
of aquatic insects. The adults feed on the nectar from the flowers of
weeds and flowers of the daisy (Chrysanthemum) and carrot (Umbellifers)
It is important to make three separate releases at two-week
intervals. This way the tiny wasps will have a chance to catch the pest
at the most vulnerable stage of their life cycle. They are very
effective, because of their astounding rate of increase.