Pest Control versus Pesticides
Today, most of the people are familiar with the ‘Pest Control gentleman’ who regularly visits homes, offices, facilities or factories and sprays pesticides all over. But this process is not only ineffective after a point in time, but also harmful to the occupants.
Regular spraying of pesticides on a scheduled basis is actually loading the environment with poison (i.e. Pesticide). This approach towards pest control is reactive and localised, and does nothing or very little to prevent recurring pest problems. The emphasis is more on routine pesticide applications which is not the solution to keep pests away.
Many organisms fall under the domain of pests, simply because they contaminate and damage food, cause injuries, spread diseases, damage property and many a time are responsible for business loss. Some of these pest threats have similar origins, whereas others are unique and require different pest management approaches and strategies. Therefore, it would be inappropriate to go for the traditional pest control methods. We should rather look for a more holistic approach of controlling pests through “Pest Management” which involves safely preventing, reducing or eliminating pests.
Several global food safety initiatives and local food safety regulations require food handlers to comply with the laid food safety norms. Besides global food safety initiative, the Food Safety Standard Authority of India too has recommended pest management systems. The presence of pesticides in indoor air is mainly due to indiscriminate blanket-spraying of
pesticides, due to outdoor contaminated air (caused by fogging) entering the structure. Pesticide fumes or particles may linger for days or weeks as air or surface contaminants.
Pest Management is like managing diabetes that requires coordinated effort to manage pests on a sustainable basis.
People generally spend majority of time indoors and tend to get exposed to pesticides. The number and concentration of pesticides detected in indoor air have been shown to be typically greater than those detected in outdoor air (Source: Non occupational Pesticide Exposure Study (NOPES): Final Report; EPA /600/3-90/003).
Awareness regarding the pesticide products, persistent level and adverse effects of various pesticides is relatively low both among the public and the pest control professionals.
In contrast to conventional methods, IPM emphasis is on routine inspection and monitoring, much higher knowledge & training, precision techniques, least toxic pesticide formulations and thorough planning and intelligently combining several strategies to achieve long-term cost effective solutions. IPM is both site-specific and pest species-specific. For example: Both German cockroaches (Blattella germanica) and American cockroaches (Periplaneta americana) avoid light and air movement. German cockroaches are most abundant in the kitchen and food preparation & food storage rooms of buildings whereas American cockroaches are commonly found in manholes and laterals of the sewer system. The German ones migrate by crawling, whereas American cockroaches can migrate either by crawling or flying.
One important aspect in control of these pests is targeting harbourages, monitoring and prevention of food and access. Thus, IPM is a Job of a Specialist who is conversed with the pest biology, habits & habitat, control strategies, tools, pesticides formulations & mode of action, plan for handling emergency situation and most importantly pesticides’ environmental impacts.
Generally, seasonal pests are accidental intruders and are sometimes forced to leave their outdoor habitat when it becomes uninhabitable due to mass migration and attraction towards exterior building lightings or when seeking a protected harbourage. Most commonly encountered seasonal pests are crickets, hoppers, moths, bugs, beetles, plant/leafhoppers and other arthropods such as sow-bugs, pill-bugs, millipedes and centipedes. These pests live and breed outdoors.
It is important to note here that the conditions that help invasions of these pests can be best utilised to formulate strategies to effectively manage these pests. Hence, altering environmental conditions can make structures inaccessible and least attractive for these pests, which is an important component of IPM.
An effective pest management plan for managing seasonal pests should include the followings:
1. Exclusion: The best approach would be to prevent seasonal pests from getting inside the facility/structure by denying access. In general, following pest exclusion methods and tools can be used depending upon the kind of pests.
- Entry & Exit Doors: Doors should be fitted with weather stripping and sweeps that close tightly. Wherever necessary, double door entry system should be installed. The distance between the two opposite door which open diagonally should be five feet.
- Windows: All facilities should preferably have fixed windows or window with wire-mesh or insect-proof screen. The wire mesh screen size vary with the pest type and a pest management professional would be able to tell this. However, the size of wire mesh may range from 14×14 to 18×18 per square inch. Indoor glass type windows/doors/ventilators should be provided with curtain-blinds or shaded so that internal light is not visible from outside, as during night these lights can attract flying insects towards buildings.
- Lighting: Many insects are attracted to ultra violet (UV) lights emitted by external building lightings. Therefore, avoid fixing lights on the external building surfaces, instead, position lights 15-20 feet away and directing them towards the building. Preferably, High-pressure sodium-vapour lamps that emit very little UV or IR and are currently thought to be the least attractive to insects should be used.
2.Habitat modification: This includes methods that eliminate or disrupt pest harbourages.
- Keep exterior perimeter of facility clear at least 2-4 feet from the foundation wall by putting a band of stone gravel or stone dust.
- The soil around the plinth foundation is often shaded, damp, and contains abundant moisture, therefore 4-6 inches thick and 60-90cm wide plinth protection should be constructed all along the plinth wall foundation.
- Aesthetic measures such as landscaping, trees, ornamental plants and lawn grass can provide suitable conditions for sustaining pests. Plants that are known to attract or harbour insects that can become pest should be avoided.
- Decaying vegetation, piles of trash, bricks, leaves, grass clippings, compost, and other favourable harbourages should be removed to manage sow-bugs, pill bugs, millipedes and centipede populations.
- Keep lawn & landscape weed free and keeping well-mowed lawns limits harbourages of hopper, crickets and leaf hoppers.
3.Mechanical control: Fly swatters can be used for killing visible and less mobile or immobile pests, whereas Insect light traps (ILTs) can be used, especially glue board type for trapping pests that have accidentally entered the facility |or structure.
4.Sanitation: Maintaining clean surroundings both outdoors and indoors removes potential areas where pests can feed, breed, and hide.
5.Chemical control: Pesticides can also be integrated into pest management plans, but at present there is no commercially available public health-use pesticides label which gives details of such pests to be controlled. However, most of the seasonal pests can be controlled outdoors with the application of least toxic agriculture-use pesticides at the concentrations most commonly used for the control of agriculture pests. These pesticides are available in liquid spray, dust or microencapsulated granules.
All commercially available pesticides in India are registered with the Central Insecticides Board & Registration Committee, Ministry of Agriculture and information on these pesticides can be obtained through CIB website at www.cibrc.nic.in/. However, more information about pesticides is also available on USEPA website at http://www.epa.gov/pesticides/.
Thus, Pest Management is like managing diabetes that requires coordinated efforts to manage pests on a sustainable basis. As we are aware of the fact that diabetes cannot be managed only with medicine, people need to follow and adopt a lifestyle as well. Moreover, it is necessary to have good understanding and cooperation between the patients and doctor to effectively manage diabetes. In the same way, pest management also requires good understanding and coordinated efforts between customers and pest management professionals (PMPs) in order to manage pests in cost effective and sustainable way. Thus, selection of good PMPs is very important for the correct diagnosis and management of pests.
In true sense, IPM is beyond pesticides which play a very small role in pest management even less than what a medicine in case of diabetes.Zakir Hussain AGM, PCI, Delhi