Problems with pesticides which reduce biodiversity:
- May kill useful/beneficial insects such as predators of the pest leading to pest resurgence.
- May kill wild plants which act as food plants for beneficial insects (reduction in wild flower biodiversity)
- May persist in the environment causing long term damage.
- May accumulate along the food chain and seriously affect the top carnivore.
- Pests may develop resistance through genetic mutation leading to selection for resistant types.
- Some pesticides may damage soil organisms, leading to erosion problems.
Safer pesticides which are highly specific and non-persistent in the environment
Biological Control: (more information can be found in the Pollution section)
- the use of one species of organism to reduce the numbers of another harmful species.
- This reduces pest number to low level at which little economic damage. E.g. Introduce a predator eg ladybirds to control aphids
Some interesting UK facts:
The Environment Agency This webpage will provide you accurate facts and figures and includes important links to other information on pesticides.
1. Matching phrases - GO
2. Case study of pesticide damage to birds of prey
There have been many well documented cases of pesticide damage to the environment. The most famous was the case of DDT and egg-shell thinning in birds of prey.
It was claimed that the widespread use of DDT was the main cause for the decline of birds of Prey in the 1960’s. This has led to a ban on the use of DDT
Read the following articles.
Article 1 – DDT, Eggshells, and Me - Ronald Bailey
Cracking open the facts on birds and banned pesticides
Article 2 – DDT - Wikipedia on-line Encyclopedia
Question: Do you think that the ban was justified? – construct your argument ‘For’ or ‘Against’, using the evidence from each article.
Locate a ‘case-study’ which clearly shows that ‘pesticides’ do damage biodiversity .