A2 Biology AQA 5.5-Biological& chemical pesticides

Pest An organism that competes with humans for food or space or is a danger to health. Pesticides Are poisonous chemicals that kills pests. 00:27 01:36 Features of an effective pesticide -Specific -Biodegradable -Cost-effective -Not accumulate Specific The pesticide is only toxic to on organism, which it is directed towards. Harmless to humans and any other organisms. Biodegradable The pesticide once applied will breakdown,into harmless substances. Cost effective New pesticides are only useful for a period of time as pests become resistant, so pesticide can become useless. Not accumulate pesticides need to make sure that it does not build up in specific parts. Types of pest control Biological Artificial Integrated Biological control By using organisms that are either predators of parasites of the pest organisms. This destroys the pest, preventing it from affecting growth. Why use biological control -To control the pest not eradicate it -If it eradicated, then the parasites would die as nothing to feed on. -Pest should be able to live where it has little or no affect. Advantages of biological control -Very specific -Pests do not become resistant -Once introduced, then control organism reproduces itself Disadvantages of biological control -does not act quickly enough as some adverse time between introducing predator and pest decreasing. -Control organism could also be a pest.