Q.What are Biocontrol Agents ? Giving examples show how they control pest infestation.
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Start your 14-day free trial to unlock the full solution →Biocontrol agents are living organisms used to suppress pest populations biologically instead of with synthetic chemical pesticides, giving effective, more sustainable and eco-friendly pest control.
What are biocontrol agents? Biological control (biocontrol) is the method of controlling plant pests and diseases through the use of other living organisms — natural enemies, predators, parasites or pathogens of the pest — rather than through toxic chemical pesticides/insecticides. Because chemical pesticides are non-specific, often harm non-target and beneficial organisms, and cause environmental pollution, biocontrol agents offer a more targeted, sustainable, and less environmentally damaging alternative.
Examples and how they control pests:
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Ladybird beetles (Coccinellidae) and dragonflies — Ladybird beetles are voracious predators of aphids, which are serious sap-sucking pests of crops; a single ladybird beetle can consume large numbers of aphids and mealybugs, keeping their population in check without chemicals. Dragonflies similarly act as good biocontrol agents to keep mosquito populations under control, since their larvae (nymphs) prey on mosquito larvae in water.
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Bacillus thuringiensis (Bt) — This soil bacterium produces crystal (Cry) proteins/toxins that are lethal specifically to the larvae of certain insects (mainly Lepidopteran pests like the tobacco budworm and cotton bollworm). Bt-based biopesticide sprays/powders are used in the field, and the cry genes have also been introduced directly into crop plants (e.g. Bt cotton, Bt brinjal) via genetic engineering, so the plant itself produces the toxin and kills the pest insect that feeds on it, without harming other organisms.
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Trichoderma species — These are free-living fungi found commonly in the root ecosystems, which act as effective biocontrol agents against several plant pathogenic fungi (root-rot causing fungi), protecting the roots of crop plants from disease-causing organisms.
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