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Timing of release Trichogramma should be released when moths are active and laying
eggs. Refer to your local history for a guide when ordering. Peak egg lay
usually occurs just after a peak in the number of moths caught in
pheromone traps. Heliothis or looper eggs are easily seen in most crops.
They are about 1 mm in diameter and creamy white, usually laid on the tops
of young leaves or near flowers.
Release rates Sixty capsules per hectare each containing 1,000 wasps is the base
rate. This rate should be increased or decreased depending on pest
pressure. It is best to make two releases, a week apart. This will
lengthen the period of the wasps activity and will provide a more even
emergence of the offspring from parasitised eggs. If regular scouting and
parasitism checks are done through the season and these reveal moderate to
high levels of parasitism then future releases may be reduced or even
omitted. (see "Monitoring Egg Parasitism" data sheet for
details).
Release capsules The capsules provide a convenient method of distributing
Trichogramma. They are useful in areas where showers are common or where
the parasitised eggs need protection from predators in the crop. Each
capsule contains a minimum of 1,000 parasitised moth eggs. The wasps will
begin to emerge around the time stated on the package if kept at the
temperature noted. If it's cooler, they will take longer to emerge and if
warmer, will emerge more quickly.
Indicator vial The package will also be accompanied by a small clear vial
containing parasitised eggs. This vial is used as an indicator of wasp
emergence. The wasps in the clear vial will emerge about 24 hours before
those in the capsules. So start placing the capsules in the field when the
wasps emerge in the clear indicator vial.
Delaying Wasp Emergence If field conditions are unsuitable for release
(raining or very hot), the capsules and indicator vial can be stored in a
standard fridge for up to 3 days. Do not allow the fridge to drop below
3ūC.
Placement of Trichogramma release capsules in
vegetables Staple the capsule
through one corner to a leaf or post (tomatoes) or drop them into a whorl
in sweet corn. In cotton and soybeans capsules can be placed in the shade
under the plants.
If it's hot select a shady spot. The wasps
will gradually move down wind so place any extra capsules along the
windward boundary of the crop. Use the Table to find the distance between
capsules.
For example, when applying 90 capsules per
hectare, place the capsules in a grid approximately 11 m by 11
m.
Inoculative releases into field
crops For low rate releases into
larger areas (cotton, maize, sorghum, soybeans) the capsules can be placed
in bands rather than a strict square grid. This cuts application time down
considerably. For example: for 60 caps/ha, place a
capule every 8 meters in bands 20 meters apart. for 30 caps/ha, place a
capsule every 13 m in bands 25 m apart for 15 caps/ha place a capsule
every 13 m in bands 50 m apart
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