This is a great program of using natures own eco balance for your own needs. It reduces your pesticide use while increasing the overall health of the plant by not adding poisons. Utilize biologicals rather than chemical pesticides is encouraged because we all have to eat and sleep in this world and integrated pest management makes it that much easier.

Problem
Aphis gossypiis a pest of many crops covering leaves with honeydew which encourages the growth of sooty moulds and virus transmission. The pest has become resistant to many pesticides except those which disrupt other systems of biological control used in the glasshouse. Therefore control using Aphidius colemanior Aphidoletes aphidimyza is highly preferable.

Aphis gossypii - Biology of the pest
Aphis gossypii can appear in the glasshouse at any time from April to September. They appear as winged adults which then reproduce asexually very rapidly to form large colonies of phloem feeding aphids.

Aphidius colemani
The parasitic wasp will lay a single egg in the aphid host by inserting its ovipositor. The Aphidius larva develops within the aphid and consumes the entire body contents. The mature larva cuts a slit in the underside of its host and attaches it to the leaf after which it spins a cocoon and pupates. At this stage the aphid resembles a swollen. papery 'mummy'. The adult Aphidius cuts a round hole in the aphid cuticle and emerges. The life cycle takes approximately 3 weeks and a single female will attack up to 300 Aphis gossypii.

Benefits
Easy and covenient to use.
The natural enemies are winged and therefore extremely mobile.
Overcomes the problem of resistance to chemicals.
Completely safe to use.

Control
Ongoing trials suggest the following introduction rates.

Preventative - when the risk of invasion by Aphis gossypii is high, introduce 0.5 per m2 weekly.

Curative - Once Aphis gossypii has been seen increase rate to 2 per m2 for 3 weeks, concentrating Aphidius in the worst affected areas.

Warning: Failure to detect early infestation may result in the removal of badly infested leaves becoming necessary.

Aphidius and Aphidoletes should be applied on the day of receipt. Bottles should be opened near infected areas. Aphidoletes can be split into smaller receptacles containing moist peat and spread around. In badly affected areas bottles of Aphidius can be hung within the crop.

Some pesticides are harmful to Aphidius and Aphidoletes. Consult your Technical Services Managers for guidance.

The small, nocturnal midge lays eggs beside aphid colonies and the orange coloured larva hatches to feed on the aphids. The larva bites aphid knee joints and injects a paralyzing toxin after which it sucks out the aphid's body fluids. A larva will kill up to 50 aphids during its lifetime. The larval stage lasts about 5 days and the life cycle is complete in 3 weeks. A female will lay between 100 and 200 eggs.

Warning
Aphidoletes will hibernate when day length falls to less than 15.5 hours. This can be avoided by the use of low intensity lights.

Control
At the first sign of Aphis gossypii or other aphids 2 to 5 Aphidoletes should be introduced per m2 for at least 3 weeks.

NB. Aphidoletes alone will not be suitable for the control of Aphis gossypii in cucumber crops. Practical use of Aphidius & Aphidoletes on crops.

Cucumbers
Introduce Aphidius colemani as a preventative measure when Aphis gossypii is known to be appearing in the area or as a curative measure when first seen in the crop. Effective monitoring is vital so that outbreaks can be dealt with immediately. It may be necessary to remove badly affected leaves or to spray them with soft soap to disperse the aphid colony. Preventative introductions should be at the rates of 0.25 - 0.50 Aphidius per m2 per week.

At first sighting of Aphis gossypii introduce 0.50 Aphidius per m2 per week, and in hot weather or in high levels of infestation 1.00 per m2 per week will be needed.

Ornamentals
Introduce Aphidius colemani as a preventative measure from the beginning of the season at 0.5/m2 every two weeks. Monitor carefully so that invasions from outside the glasshouse late in the season may be dealt with quickly.

Aphidoletes may be introduced preventatively but will be more effective after aphid colonies are established.