Pesticides are mixtures of compounds used to ward off or kill pests. Commercial grade pesticides are proprietary mixes of synthetically produced compounds however some pesticides occur naturally. Natural pesticides can even be biological organisms such as bacterium.
Types of Pesticides
Current legislature demands that pesticides be classed according to their active ingredients and the particular pests that they deal with. The most common types of pesticides are:
Bactericides which are designed to halt the spread of bacteria. A common bactericide is chlorine which is added to swimming pools. Bactericides are also used on plants to prevent blight which citrus fruits are particularly susceptible to. Disinfectants also kill bacteria however they are not considered as pesticides.
Baits which are used as lures or poisons to deal with larger pests such as raccoons and foxes. They are mixed in with the food that the large pest usually eats. Slugs and insects can also be dealt with using bait.
Nematicides which kill nematode worms in the soil.
Insecticides which deal with insects. They come in solid, liquid or aerosol forms. When using insecticides to handle insects you have to know which kind of insect that you are dealing with. For example, crawling pests such as ants and cockroaches are best dealt with using surface powders while flying insects will require misting or fogs. Insecticides work by entering the insect’s body through its dermal layer, orally by being eaten or into their respiratory systems by being breathed in. Organic pyrethrins are the most popular type of insecticide because they kill a wide variety of insects. They are fast-acting and have low toxicity for mammals.
Herbicides to help get rid of weeds. Contact herbicides kill only the plant that you place it on so as to protect the crops you want to grow however this is a difficult method to use on a large farm. Selective herbicides can be used on entire crop fields and will only kill the weeds as long as they are used correctly. Non-selective herbicides will every plant that they come into contact with.
Fungicides which are similar to herbicides except that they are designed to be especially lethal to fungal pests such as mildew and mould.
Genetically Modified Organisms
Genetically Modified Organisms which are a relatively new kind of pesticide. Scientists have discovered how to alter certain genes within desired crops that makes them especially resistant to common pests. For example, a gene from a particular bacterium can be taken and added to the genome of cotton plants to make cotton plants resistant to attacks from bollworms. GM foods are believed by some people to be the solution to the world hunger crisis however others believe that eating foods that have altered genes will have grave consequences for human health.
How do Pesticides Work?
Pesticides are designed to make an environment inhospitable for a particular organism without limiting the ability of the desired organisms to thrive. Effective pesticides reduce pest populations by inhibiting their metabolism. They are lethal in most cases.
- Make the environment uncomfortable for the pest,
- Inhibit the pest’s ability to reproduce,
- Make it harder for pests to hang on to leaves,
- Incapacitate a pest’s senses so that they can’t eat.
A certain class of pesticides have residual effects which last for long periods of time after their application. In such cases their effects can last for months. Triazine herbicides are a good example of long lasting pesticides. Their compounds stay in the soil and kill any new shoots of weeds that might appear. Long-lasting pesticides are generally frowned upon because they can cause a toxic load within the soil that is difficult to clean out.
Read the Labels
You must remember that pesticides are usually poisons therefore you must read the label on the box so that you know how to apply them without harming yourself or those around you. Every pesticide commercially available must come with a Material Safety Data Sheet which tells you how to treat yourself if you accidentally come into contact with it. In the odd case that the pesticide does not have information on the label then you would be wiser to choose a brand which does. The labels are there for your safety. Pesticide labels usually have:
- The product’s name,
- Directions for use,
- First-Aid Instructions,
- List of active ingredients,
- Net content weight,
- Product registration number.