Whitefly
Whitefly, although its name implies, are not flies. They are often mistaken as aphids with cast-off skins, but you easily distinguish that they are not such because they easily flutter up and fly when disturbed. On the contrary, aphids will simply drop off when it senses danger.
The Greenhouse Whitefly
There are approximately 20 species of whiteflies in Australia, but the worst pest that attacks varieties of plants particularly beans and tomatoes is the greenhouse whitefly (Trialeurodes vaporariorum).
Description of Greenhouse Whitefly
To easily identify a greenhouse whitefly infestation in your farm or garden, you may observe these features:
resemblance to tiny pure white moths
resemblance to aphids with cast-off skin
adults displays a 3 mm wingspan that is covered with white waxy coating
it has a full life cycle of 20 to 30 days, with eggs that often appear on the
underside of leaves
it is present all year round since it thrives as long as there is a host that feeds it
Signs of Greenhouse Whitefly Infestation
You will have an early warning of greenhouse whitefly infestation if the following appears on your plants:
yellow mottling on the leaf suface
leaf loss
stunting growth
wilting
appearance of black sooty mould
sudden attraction of ant
Management and Control of Greenhouse Whitefly
The following methods are to be used when you notice your garden has been infested with greenhouse whitefly.
Biological Control
Greenhouse whitefly has been a result of excessive use of pesticides on farms, thus resulting to the death of natural enemies of this species. Introduction of ground beetles, spiders, hoverflies, mired bugs, damsel bugs, and lacewings will result to a decrease in its number. However, you should know how to control the growth of these enemies because they may pose threat to your plants after all the whiteflies has been eliminated.
The enemy commonly bought by farmers to get rid of greenhouse white flies is the tiny wasp called Encarsia Formosa. It is readily available from the Biological Services and other biological control shops in Australia. Feel free to give them a call to receive sufficient amount that will help discard of these pests in your farm and garden plants.
Cultural Control
Greenhouse whiteflies move slower in the early morning, so you may wish to do a vacuuming job before they start laying eggs. Place the gathered pests in a plastic bag and freeze them for 24 hours to guarantee they will never go back to life and feed on your crops.
Sticky yellow traps hanged above the plants will prove to be an effective combat remedy against these pests. You may use this early in the season to avoid their sudden invasion. Whiteflies will easily stick to these traps and control their spread to other plants in your vicinity.
Floating row covers or mosquito netting may also work, but only for early season protection.
Do a personal inspection of your plants and start removing older leaves with young whitefly stages to discourage their growth and development.