In this article we will discuss about how to control pests using chemicals.
Introduction:
The cultural and other agro-technological approaches are quite often not sufficient to keep the pests at such a level that economic losses could be avoided. Therefore, chemical agents are resorted to both as preventive and curative measures to minimize the pest incidence and damage. The chemicals to combat different kinds of pests are called pesticides.
Based on the target organisms, these pesticides are grouped into various categories, viz., insecticides (insects), herbicides (weeds), fungicides (fungi), nematicides (nematodes), rodenticides (rodents), etc. A good pesticide should be cheap to produce and potent against pests. It should not endanger the health of man and domestic animals, should ultimately break down into harmless compounds, so that it does not persist in the environment.
In order to determine the potency of an insecticide, both the relative toxicity and the specific toxicity are to be worked out. The value of median lethal dose (LD50) of various poisons against a given insect species indicates the relative toxicity. LD50 is expressed in terms of dosage in mg/kg of body weight necessary to kill 50 percent of a population of male white rats/rabbits/guinea pigs.
The specific toxicity may vary a great deal from species to species. A poison may be highly effective against one and quite ineffective against another species. There are few compounds which have all the qualities considered desirable and, therefore, we have to accept those which are comparatively cheap, more effective and less dangerous.
Historical Aspects:
Since the early nineteenth century, certain inorganic compounds, like lead arsenate, sodium fluosilicate, Paris green and zinc phosphide have been used as stomach poisons for the control of insects or other pests. These poisons were administered along with food and they were equally potent against mammals, including man and domestic animals.
Some of them, when not properly applied were even phytotoxic. With the discovery of insecticidal properties of certain plant extracts, the insecticides like nicotine sulphate, pyrethrum and rotenone came into prominence. These insecticides were comparatively safe for mammals. This important fact was kept in mind by the organic chemists while looking for other safer organic compounds which could be used as insecticides.
DDT (Dichlorodiphenyl trichloroethane) synthesized in 1874, but discovered as an insecticide in 1939, was one such compound. In fact, this was the first wonder insecticide that appeared commercially and it was soon followed by BHC (Benzene hexachloride), which is a misnomer for HCH (Hexachlorocyclohexane).
By now, thousands of compounds have been synthesized and tested for their insecticidal properties. Quite a few are appearing in the market. Those which are finally accepted have to be subjected to certain rigorous tests. A good insecticide should be cheap to produce and potent against insect pests.
It should not endanger the health of man and domestic animals, and should ultimately break down into harmless compounds so that it does not persist in the human environment. It is not easy to find new compounds having all these desirable qualities; hence fewer chemicals are being added to the list of good insecticides than one would expect.
Modern synthetic pesticides gave mankind unprecedented manipulative power to suppress the pest populations. For the first time in world history, little more than 50 years ago, man had curative tools to fight agricultural pests and vectors of human diseases.
In fact, green revolution was driven by a wide array of different chemical technologies including the synthetic organic pesticides. Availability of pesticides made cultivation of crops profitable in areas where this was previously not possible because of pest problems.
Increased agricultural productivity associated with high levels of pest control, improved crop and animal genetics, availability of fertilizers and mechanised production systems allowed food supplies to increase and standard of living to improve in many regions of the world.
Classification of Insecticides:
Insecticides can be grouped in various ways, viz., according to the mode of their entry (stomach poisons, contact poisons and fumigants), and their mode of action (physiological poisons, protoplasmic poisons, respiratory poisons and nerve poisons) or according to their chemical composition. As an insecticide may enter and act in an insect body in more than one way, it may be desirable to group them according to their chemical nature.
Chemically, the types of insecticides are:
(i) Elements, such as sulphur, phosphorus, thallium, mercury, etc.
(ii) Inorganic compounds such as lead arsenate, sodium fluosilicate, zinc phosphide, Paris green, etc.
(iii) Organic compounds – (a) compounds of plant origin such as pyrethrum, nicotine, rotenone, etc. (b) animal and mineral oils such as fish oil, diesel oil, etc., (c) synthetic organic compounds such as DDT, malathion, carbaryl, etc.;
(iv) Poisonous gases such as hydrogen cyanide, ethylene dichloride, carbon tetrachloride, methyl bromide, phosphine, etc., used as fumigants.
For those interested in insect control, however, it is more meaningful to list these compounds according to their mode of entry in the insect body and lethal action on the pests.
The above mentioned compounds could, therefore, be rearranged under the following categories:
1. Stomach Poisons:
They are generally used against insects with chewing type of mouthparts and under certain conditions against those with sponging, siphoning, lapping or sucking mouthparts. Some of these poisons are also mixed with food for killing higher animal pests, such as rodents, jackals and birds.
The stomach poisons are applied in many ways. The foliage or other natural food is thoroughly covered with poison or the poison is mixed with food along with an attractant which makes the mixture very acceptable. Sometimes, these poisons are sprinkled in the runways of insects. As the insects move about, they pick up the poison on their feet or antennae and while cleaning these parts with mouth, they ingest the poison.
Certain organophosphates act as systemic insecticides, which are taken up by the plant or animal system, and are translocated into tissues. When insect pests feed on these tissues, they die because of the poisoned cell sap.
For the stomach poisons to be acceptable in common use, they should have certain prerequisites:
i. The concentration which is applied to the plant for insect control should not be injurious to the foliage.
ii. The non-systemic compound should generally be insoluble in water; otherwise it might be absorbed through leaves and roots and, thus, poison the plants.
iii. It should be potent so as to kill the pest quickly and, thus, save the crop.
iv. It should be inexpensive and be easily available in large quantities.
v. The compound should not be distasteful to the insects, so that they may not be repelled.
vi. Chemically, the compound should be stable, so that it does not lose its toxicity while in shipment, in storage or after it has been applied to the plants.
vii. It should also not break down too easily when mixed with other chemicals.
viii. The insecticide should have the physical properties of adhering to the plant surface on application and yet after a certain period it should disintegrate or be washed away by rain, etc., so that it does not persist on the plants for long periods and, thus, endanger the health of farm animals or of human beings.
The stomach poisons are applied as sprays, dusts, dips or baits. These poisons include inorganic and organic compounds. Among the inorganic compounds are the lead arsenate, calcium cyanide, Paris green (copper acetoarsenite), sodium flouride, sodium fluosilicates and sodium aluminofluoride (cryolite) and borax.
2. Systemic Poisons:
An insect with piercing mouthparts sucks cell-sap through its proboscis which it embeds into the plant or animal tissue. The only way a poison can reach its stomach is through the plant or animal system. It is only in recent years that some highly effective systemic insecticides have been discovered. A systemic insecticide when applied to seeds, roots, stems or leaves of plants, is absorbed and translocated to various parts of the plant in amounts lethal to insects which feed on them.
Some of them are quite specific to certain groups of insects. The systemic insecticides have a great value in an integrated approach to pest control, because through their application the parasites, predators and other natural enemies of the pests escape damage. Most of these insecticides act primarily as stomach poisons, and they include oxydemeton methyl, dimethoate, phosphamidon, aldicarb, phorate, carbofuran and others.
3. Inert Dusts:
Fine dusts of various compounds have been used for a long time to control insect pests of crops and stored grains. These dusts are mixed with the grain or dusted on a surface from where the insects pick up the fine particles which cause irritation and abrasions in the cuticle, particularly at the body articulations. It results in excessive loss of moisture from the body of an insect which ultimately dies of desiccation. These dusts are based on fine sand, powdered cowdung ash (which also acts as a hygroscopic compound), calcium carbonate, silica, aerogel, etc.
4. Contact Poisons:
The other most effective and most prevalent method of insect control lies in the use of contact poisons, a large number of which are now available. The contact poisons are applied as sprays or dusts, either directly onto the body of insects or to the places frequented by them.
These poisons kill the insects either by clogging spiracles and respiratory system or by entering through the cuticle into the blood and acting as nerve or general tissue poisons. It has been shown that the insect cuticle possesses very high absorptive properties, so that the lethal dose applied externally is almost the same as the quantity required to kill by injecting it into the body.
The contact insecticides, even though applied in the form of emulsions, suspensions or dusts are highly lipophilic and are readily absorbed by the lipids present in the epicuticle of insect exoskeleton. The residual film of a contact insecticide may kill an insect by its action on the sensory organs present in the tarsi of its legs.
Like the stomach poisons, the contact poisons also must have certain qualities before they can be accepted for use. Some of them are also phytotoxic. Others, like mineral oils, are so lethal to the foliage that they can only be applied in winter as dormant sprays when there are no leaves on the plants.
Even among the milder insecticides which are used as summer sprays or dusts some have phytotoxic effect. For instance, high doses of DDT and HCH are known to cause phytotoxicity in plants. Most of the insecticides damage citrus inflorescence and, therefore, they cannot be applied when plants are in blossom.
Some of these compounds are also toxic to mammals and are readily absorbed through the skin for instance, parathion and endrin, when sprayed on crops in the field during the monsoon can easily cause death of the operators, if due precautions are not taken.
Insecticides like DDT and HCH, which do not act as acute poisons, may cause very serious chronic ailments among mammals. Because of their slow breakdown over time, they are preferably deposited in the adipose tissue and are secreted through milk. Thus, the babies are exposed to the risk through contaminated food.
There is a wide range of contact poisons available in the market today. Among the inorganic compounds, sulphur, sodium fluoride and arsenicals may be mentioned but these are very limited in use. The mineral oils, including diesel oil, kerosene oil, crude oil and animal fats, including fish oil or the soaps prepared from them are also used as winter and summer sprays.
A number of complex organic compounds which are extracted from various plants have the remarkable property of being very safe for man and domestic animals. These compounds include nicotine in sulphate form, anabasine, rotenone, pyrethrum, neem extract, dharek extract, etc.
A wide spectrum of new synthetic organic compounds has revolutionized the modern practices of pest control. The major groups include chlorinated hydrocarbons (DDT, HCH, aldrin, etc.), carbamates (carbaryl, aldicarb, carbofuran, etc.) and the organophosphates (malathion, oxydemeton- methyl, monocrotophos, etc.).
5. Fumigants:
Poisonous gases, derived from either solids or liquids, are used as fumigants to kill insect pests of stored grains and other products in warehouses, museums, godowns, etc. They are also used to kill insect pests found in animal sheds or human dwellings; soil-infesting grubs and nematodes, the scales infesting nursery stock, the borers found in trees or wooden structures; to control all kinds of greenhouse pests and even worms found inside the intestines of animals.
Since practically all the fumigants are deadly poisons, great care is needed in their use. Some of the common fumigants, both old and new include nicotine, hydrogen cyanide, carbon bisulphide, sulphur dioxide, paradichlorobenzene, naphthalene, ethylene dichloride and carbon tetrachloride mixture, methyl bromide, phosphine, DBCP, D-D (dichloropropane-dichloropropene) mixture, etc.
The kill obtained is determined to a great extent by the temperature and atmospheric pressure at which the fumigation is done. In a partial vacuum, the penetration is very much enhanced and at lower temperatures a longer exposure is required to kill the pests than at room temperatures (21- 37°C).
The duration of effective exposure depends upon the gas used. This is determined by its toxicity, dose, and rate of penetration, its absorption by the food stuffs, the tainting or discoloration of products, the chemical composition and the moisture content of the materials to be fumigated.
6. Miscellaneous Chemicals:
Under this group are a number of chemicals, both new and old, which cause changes in the physiology and behaviour of insects and are, thus, used either to repel them or to kill them. Chemosterilants such as apholate, tepa and metapa are fed to the insects along with food and through their physiological action they cause sterility and ultimately the pest population declines.
Antifeedants, such as neem seed extract or 4′-(dimethyl triazene acetanilide), when sprayed on plants or mixed with food make them distasteful to the insects who stop eating and ultimately die of starvation.
Repellents are another group of chemicals which are only mildly poisonous but prevent damage by making the food unattractive or offensive. These substances generally have a specific effect and are effective against certain groups of insects only. Trichlorobenzene is effective against crawling insects such as termites and ants, and is applied in the basement to provide protection to buildings.
Adhesive tapes, carrying bichloride of mercury, when fixed around the legs of a table, also provide protection against ants. Heavy oils applied at the base of poultry roosters act as barriers against poultry lice and mites. Bordeaux mixture and lime-sulphur wash, repel leafhoppers and certain chewing insects.
Oil-citronella or dimethyl phthalate (Odomos) when applied as liquid or mixed with a vanishing cream keeps mosquitoes away from human beings. Smoke keeps biting flies away from cattle. Oil of cedar, naphthalene or dry leaves of neem (Azadirachta indica A. Juss.) protects warm clothes and carpets against the attack of moths and beetles.
There are still other chemicals which repel insects from sitting on wounds and laying eggs there. For example, pine-tar oil and diphenylamine, when applied to the skin near the wounds of animals, keep the screwworm flies away so that they do not oviposit. The wheat crop can be protected against damage by birds like sparrows, by spraying it with Thiuram (tetramethyl thiuram disulphide).
When insects are to be poisoned through baits, it is advantageous to mix an attactant with the food which gives olfactory stimulation. Many such attractants occur naturally either in the food, or as pheromones, which are secretions released by other members of the same species that promote aggregation, mating and other types of behaviour.
Apart from these natural attractants, a number of other chemicals are also known to be effective. In United States, a mixture of 9 parts of geraniol and 1 part of eugenol serves as a food lure for the Japanese beetle, Popillia japonica Newman. Fermented sugar or syrups act as attractants for moths and butterflies.
Sometimes, the addition of a chemical makes this food even more attractive. For example, the essential oil anethol is particularly luring to the codling moth, Cydia pomonella (Linnaeus) and isoamyl salicylate to the tomato and tobacco hornworm moths, Protoparce spp. Ammonia strongly attracts many insects and its slow liberation from a mixture of glycine and sodium hydroxide has been used in United States for luring the walnut husk fly, Rhagoletus completa Cresson.
Sometimes, closely related species of insects exhibit a marked preference for one chemical over the other. The Oriental fruitfly, Bactrocera dorsalis (Hendel), is attracted to methyl eugenol, whereas the melon fruitfly, Bactrocera cucurbitae (Coquillett), is attracted to anisyl acetone. Metaldehyde which is lethal by itself also acts as an attractant in poison baits for snails and slugs.
There is still another group of chemicals which, when fed to rodents and other mammals, produces physiological changes in the blood and inhibits coagulation. When chemicals, like warfarin, fumarin, coumafuryl (Rodafarin) are fed to rats, they die of internal haemorrhage.
Pattern of Pesticide Consumption:
The use of synthetic pesticides in agriculture is the most widespread method of pest control. Farmers spend approximately $ 4.1 billion on pesticides annually on global basis. This high cost is justified by a direct return of $ 3-5 for every dollar spent on pesticides.
The world’s pesticide consumption is estimated to be about 3.0 million tonnes, which includes 1500 active ingredients and 50,000 or more commercial products. About 46 per cent of the total pesticide use are herbicides, 26 per cent insecticides, 23 per cent fungicides and 5 per cent other pesticide groups.
About 34 per cent of the total pesticide is consumed in USA, 45 per cent in Europe and 20 per cent in developing countries. The Asia-Pacific region accounts for 16 per cent of the total pesticide consumption, out of which 75 per cent is used on rice, cotton and vegetable crops.
About 85 per cent of all pesticide use in the world is for agriculture. However, the relative amount of each type of pesticide varies from country to country. For example, 75 per cent of the pesticides used in Malaysia are herbicides, and insecticides account for only 13 per cent.
In the Philippines, insecticides account for 55 per cent of the total pesticide use, and fungicides account for 20 per cent. India with about 4 per cent of the world cropped area has a share of around 2 per cent of the global pesticide consumption. About 60 per cent of the pesticides used in India are insecticides.
India was one of the first countries in the third world to start large scale use of pesticides for the control of insect pests of public health as well as of agricultural importance. At present, 238 pesticides have been registered under Insecticides Act 1968 in India. Some of the most toxic and persistent pesticides have been banned or restricted for use.
The consumption of pesticides for pest control in agriculture picked up after the introduction of high yielding varieties in 1966-67. The total amount of pesticides used in the country increased from 154 metric tonnes in 1953-54 to 61,357 metric tonnes in 1994-95. Earlier projections had put the pesticide demand at nearly 100,000 metric tonnes by the year 2000.
But in view of the ban on DDT, HCH, aldrin, etc., high potency (and consequently lower required dosages) of new insecticides especially synthetic pyrethroids and high priority being accorded to IPM, the pesticide consumption has shown a decreasing trend during the last few years. The pesticide consumption in India had come down to 39,773 metric tonnes during 2005-06. Thereafter, there is a slight increase in consumption reaching 64380 and 41822 metric tonnes during 2008-09 and 2009-10, respectively.
India is the third largest consumer of pesticides in the world and highest among the South Asian countries. Up to 1995-96, the major group of chemicals used in agriculture was insecticides (80%), followed by fungicides (10%), herbicides (7%) and others (3%).
Thereafter, the consumption of insecticides declined with simultaneous increase in the consumption of herbicides and fungicides. The consumption of insecticides in 1999-2000 was 60 per cent, fungicides 21 per cent, herbicides 14 per cent and others 5 per cent.
During this period, types of insecticides used also changed, the percentage of organochlorines decreased from 40 to 14.5 per cent, carbamates from 15 to 4.5 per cent and synthetic pyrethroids from 10 to 5 per cent, but there was a sharp increase in percentage of organophosphates from 30 to 74 per cent.
A modest consumption (2%) of natural pesticides (neem and Bt formulations) was also registered during this period. According to latest estimates, insecticides account for 61.39 per cent, followed by fungicides (19.06%), herbicides (16.75%) and others (2.80%).
Along with the change in the amount of pesticides used, the potency of some of the new chemicals is also much higher. DDT was applied at dosages of 1-2 kg a.i/ha for the control of different pests; the OPs, monocrotphos and quinalphos were effective at 250-500 g a.i./ha and the SPs, fenvalerate and cypermethrin at only about 50 g a.i./ha. In case of deltamethrin, the dosage has been further reduced to 10 g a.i. per ha. Thus, there has been more than 100- fold increase in the potency of new insecticides.
India’s consumption of pesticides is quite low when compared to many other countries. The highest consumption is reported by the Republic of Korea (16.56 kg a.i. ha-1), followed by Italy (13.35 kg) Hungary (12.57 kg) and Japan (10.80 kg), whereas India consumes only 380 g per ha. Japan spends $633 per ha on pesticides, South Korea $255 per ha and Philippines $24 per ha as compared to $3 per ha in India.
Based on 2009-2010 data, four states, viz. Haryana, Punjab, Maharashtra and Uttar Pradesh consumed more than 4000 metric tonnes (technical grade) pesticides annually. Seven states, viz. Andhra Pradesh, Gujarat, Jammu & Kashmir, Karnataka, Rajasthan, Tamil Nadu and Orissa consumed pesticides between 1000 and 4000 metric tonnes. Six states, viz. Bihar, Chhattisgarh, Himachal Pradesh Kerala, Madhya Pradesh, and Uttrakhand consumed pesticides between 100 and 1000 metric tonnes.
Nine states (Arunachal Pradesh, Assam, Goa, Assam, Jharkhand, Manipur, Mizoram, Nagaland, Tripura and Delhi) and union territories of Pondicherry, and Andaman & Nicobar Islands consumed pesticides between 10 and 100 metric tonnes annually. Two states (Meghalaya and Sikkim) and four union territories of Chandigarh, Dadra & Nagar Haveli, Daman & Diu, and Lakshadweep consumed less than 10 metric tonnes pesticides annually.
The consumption pattern of pesticides on different crops is also highly uneven. Both at the national as well as at the global level, cotton crop receive a disproportionately large share of pesticides.
In India, cotton crop receives about 45 per cent of the total consumption of pesticides, followed by rice (23%), jowar (9%), vegetables and fruits (7%), wheat (6%) and pulses (4%). On the other hand, consumption of pesticides on many important crops like barley, gram, jute, rapeseed- mustard, soybean, sunflower and tobacco is even less than 1 per cent. At the global level, horticultural crops receive the highest proportion of pesticides.
Potential and Constraints of Pesticides:
Pesticides have played a major role in raising world’s food production. Availability of pesticides made cultivation of crops profitable in areas, where this was previously not possible because of pest problems. Pesticide use almost universally brought about increased crop production by minimising pest damage and thereby, encouraging farmers to adopt better agronomic practices and obtain high yields.
The development of high yielding varieties of crops which ushered in the green revolution was possible only under the protection provided by the pesticide umbrella. In spite of their glorious past and great potential in future, pesticides face mounting public pressure due to increasing environmental problems caused by their use.
Despite the various environmental problems caused by their use, pesticides continue to be the single most widely used method of insect pest control. Pesticides will continue to play an important part in most IPM programmes in the foreseeable future in view of a number of advantages over alternative means of pest control.
Some of the advantages are as follows:
i. In view of their persistent action, most of the pesticides provide a long lasting pest control.
ii. Pesticides provide control of some pests where no other effective tactics were previously available.
iii. When an increasing insect population approaching ETL is observed in the field, pesticides are often the only means of preventing economic damage.
iv. Pesticides are easily available across the counter in convenient and ready to use packing.
v. Pesticides often provide rapid remedial action against the targeted pest and allow rapid control of an existing pest problem.
vi. Pesticides are easy to apply and large areas can be covered in a relatively short time.
vii. Even if there is a complex of several insect pests causing economic losses, a single insecticide or a combination of two insecticides in a single application may control the whole pest complex.
viii. When properly used under appropriate conditions, pesticides provide a relatively predictable level of control. There is often a greater level of uncertainty associated with the use of other tactics.
ix. Use of insecticides protects the crops from the ravages of insect pests and thus provides stability in yield as well as in farmers’ income.
x. The use of insecticides is compatible with other components of IPM under intensive agriculture and modern farming conditions.
xi. Pesticide production, quality, handling, storage, transportation, safe use, consumer safety, etc., are governed by legal enactments in each country as well as globally.
Many problems arise with pesticide use and misuse. The magnitude and importance of these problems vary considerably among pesticide categories. As with the advantages, some problems are real, but others are only perceived.
i. The repeated usage of a single pesticide may lead to the selection of pests that are resistant to the pesticide. This is an enormous problem for use of all types of pesticides, but has been particularly important with insecticides, herbicides, fungicides, and bactericides (antibiotics).
ii. When the pesticide (usually an insecticide) kills the targeted pest, but also kills beneficial insects, the pest population often will increase to a level, higher than the level preceding the application. The phenomenon is called pest resurgence. When the survivors of the targeted population begin to reproduce, their number grows exponentially because the beneficiaries that once limited population growth are no longer present.
iii. When the pesticide kills the key pest, but not a minor (secondary) pest, the minor pest population may increase and become important. This is a problem for both insecticide and herbicide use.
iv. Pesticides may harm useful organisms, such as honey bees, or beneficial insects that are critical in the biological control of pest populations. Some pesticides are toxic to wildlife.
v. Pesticides may move from the place where they were applied, resulting in contamination of surface water or groundwater, and pesticide accumulation in the food chain.
vi. Pesticide residues remain in the soil, and on or in harvested produce after the application of a pesticide. Residues may be of particular concern if pesticides are applied incorrectly.
vii. Due to their toxicity, pesticides have the potential to cause illness in farm workers, especially for those working in hand-harvested fresh market crops.
viii. Although low cost may be a reason for the use of pesticides, in other situations pesticides are an expensive choice; this is especially true for management of certain insects where biological control is a feasible alternative.
ix. Misuse of pesticides may lead to more frequent applications and require higher rates of the product needed to control the same pest. This phenomenon has been called the pesticide treadmill and it is the result of severe ecosystem disruption.
The development of modern synthetic pesticides has had an enormous impact on the lives of people all around the globe. Pesticides are likely to remain an integral and necessary component of pest management systems in the foreseeable future, also particularly in the annual cropping systems with multiple pests.
Furthermore, the use of pesticides has made possible the profitable production of many commodities in the presence of potentially devastating pests. However, it is critical that the use of pesticides be viewed as a single component of an ecologically and biologically based system in order to conserve and prolong the utility of the declining pool of pesticides.
New pesticides with more specific modes of action and reduced spectrums of activity may be more suited for large scale agricultural systems utilising a vast arsenal of chemical control options. The efficacy of existing pesticides can also be enhanced by developing more efficient formulations.
There is a need to regulate the use of pesticides in developing countries. A number of developing countries promote pesticide reduction through official policies or regulation. China introduced the Green Certificate programme and banned highly toxic pesticides from vegetable crops.
Biological control is a national priority for Cuba; the new policy is intended to make integrated pest management (IPM) biointensive, with 80 per cent of pests managed through biological control. A National IPM Committee in Malaysia is reducing pesticide use and increasing farmer knowledge of other pest management techniques. Iran constituted the High Council of Policy and Planning for Reduction of Agricultural Pesticides.
India, Indonesia, Nepal, Philippines and Sri Lanka have adopted national IPM policies. The Food and Agriculture Organization and the World Health Organization are collaborating with the international community and developing nations to formulate pesticide policy. All these efforts would go a long way in regulating the use of pesticides in sustainable IPM programmes.