Pollution

An example in more detail:

The parasitic wasp (Ecasaria Formosa) and the control of whitefly (Trialeurodes vaporarium

• A glasshouse is an ideal place for growing plants but also an ideal habitat for a pest.
• Tomatoes and cucumbers can have a serious pest called a white fly.
• This small moth-like insect lives for 35 days and each female can produce up to 500 eggs.
• The adult and larva feed by sucking sap. They produce a sticky sugary secretion which encourages fungal growth on the leaves and fruits. This seriously disrupts photosynthesis and therefore crop yields.
• The whitefly can be controlled by insecticides although the pest is now showing resistance.
• Biological control involves introducing a parasitic wasp (Encarsia formosa) into the glasshouse. The female wasps lay eggs on the whitefly. These hatch into minute larvae which pupate and kill the host whitefly.
• These emergent adults then continue the cycle, females laying 60-100 eggs.
• The method is cheap and highly effective in controlling the pest.
   

What happens when biological control does not work effectively? Is integrated control the future?

• Often biological control cannot work entirely on its own as pest numbers are difficult to control, especially at the beginning of an infestation.
• New methods now use biological control in conjunction with other control methods – this is known as integrated control.
• Additional methods could include:
• Producing pest-resistant crops.
• Cultivation techniques to reduce pest numbers.
• Targeted application of highly-specific pesticides.

 Pollution from fossil fuels