Servis Utama

Conventional Pest Control

Pests can be defined as any animals, plants, or microorganisms that interfere with some human purpose. For example, insects may be considered pests if they eat crop plants or stored foods, or if they are important vectors in the transmission of diseases of humans or domestic animals. Plants are considered to be pests, or weeds, if they excessively compete with crop plants in agriculture or forestry, or if they have an unwanted aesthetic, as is the case of weeds in grassy lawns. Microorganisms are regarded as pests if they cause diseases of humans, domestic animals, or agricultural plants. In all of these cases, humans may attempt to manage their pest problems through the use of pesticides, that is, chemicals that are toxic to the pest.

Very important benefits can be gained through the judicious use of pesticides. For example, agricultural yields can be increased, and stored foods can be protected. Human lives can also be saved by decreasing the frequency of diseases spread by arthropods; malaria, for example, is spread through bites of a few species of mosquitoes.

Fumigation

Fumigation is a method of pest control that completely fills an area with gaseous pesticides to suffocate or poison the pests within. It is utilized for control of pests in buildings (structural fumigation), soil, grain, and produce, and is also used during processing of goods to be imported or exported to prevent transfer of exotic organisms. Structural fumigating techniques differ from building to building, but in houses a rubbertent is often placed over the entire house while the pesticides are being released into the residence. This concentrates the gases and prevents them from escaping and doing harm to people in the neighborhood. During this time the residents of the house must find an alternate residence for up to a week depending on the fumigant used, which in turn depend on the severity of infestation and size of the house.

Methyl bromide was among the most widely used fumigants until its production and use was restricted by the Montreal Protocol due to its role in ozone depletion.

Widely used fumigants include:

• phosphine
• 1,3-dichloropropene
• chloropicrin
• methyl isocyanate
• hydrogen cyanide
• sulfuryl fluoride
• formaldehyde

Fumigation is a hazardous operation, and generally it is a legal requirement that the operator carrying out the fumigation operation holds official certification to perform the fumigation. Fumigation usually involves the following phases.

First the area to be fumigated is usually covered to create a sealed environment; next the fumigant is released into the space to be fumigated; then, the space is held for a set period while the fumigant gas percolates through the space and acts on and kills any infestation in the product, next the space is ventilated so that the poisonous gases are allowed to escape from the space, and render it safe for humans to enter. The correct ventilation of the area is a critical safety aspect of fumigation. It is important to distinguish between the pack or source of the fumigant gas and the environment which has been fumigated. While the fumigant pack may be safe and spent, the space will still hold the fumigant gas until it has been ventilated.