INTEGRATED PEST MANAGEMENT STRATEGIES (IPM)
The following information is about Integrated Pest Management Strategies.
Introduction to Integrated Pest Management Strategies or IPM
In 1972 the term IPM was accepted by CEQ (Council of Environmental Quality) where IPM includes.
I – Integration that is the harmonious use of multiple methods to control the impact of a single pest as well as multiple pests.
P – Pest- any organism that is detrimental to humans including vertebrates and invertebrate or weed or pathogens.
M – Management refers to a set of decisions or rules based on ecological principles, economic and social consideration.
The backbone of management of pest in an agricultural ecosystem is the concept of economic injury level (It is the level of the pest up to which the damage can be tolerable).
Integrated Pest Management Strategies – Why Pest Management?
After World War II the use of pesticides mushroomed, but with all the benefits of the use pesticides, it has adverse side effects not just on humans but also in animals. An over-reliance on chemical pesticides led to the development of pesticide resistance, development of multiple resistance, the emergence of a secondary pest as major pests, the resurgence of pests, elimination of natural enemies of pests, hazards to nontarget species, hazards to agricultural workmen and deleterious effects on the environment.
Integrated Pest Management Strategies – Evolution of IPM
The green revolution has attained self-sufficiency in food through the introduction of hybrids and high yielding varieties. Intensive cultivation of HYV invited or demanded more of inputs in the form of fertilizers especially inorganic which in turn attracted more of pest and diseases. This necessitated intensive control measures to curtail the damage caused to the crops and the control was achieved mainly through chemical pesticides. Continuous use of chemical pesticides led to pest resurgence, resistance, residues and ecological imbalance by killing predators and parasitoids thus affecting prey-predator dynamics and resulting in environmental pollution. The importance of integrated approaches to pest control was then felt and the concept of IPM evolved. IPM seeks to minimize the disadvantages associated with use of pesticides and maximizing socio, economic and ecological advantages.
Integrated Pest Management Strategies – Components or tools of IPM are,
- I) Cultural methods
- II) Mechanical methods
III) Physical methods
- IV) Biological methods
- V) Legislative methods and
- VI) Chemical methods.
Cultural Methods Of Pest Control In Integrated Pest Management Strategies
The manipulation of cultural practices at an appropriate time for reducing or avoiding pest damage to crops is known as cultural control. The cultural practices make the environment less favourable for the pests and or more favorable for its natural enemies. It is the cheapest of all methods.
- A) Normal agricultural practices, which incidentally ward off certain pests:
By adopting these, the farmers get two-fold benefits
(1) Improvement of crop yields and
(2) The population of certain pests do not increase abnormally
- i) Proper preparatory cultivation: Several insects which live or hide in the soil get exposed to the sun as well as predators like birds etc due to Proper preparatory cultivation. Eg.Pupae of moths, roots grubs etc.
- ii) Clean cultivation: Removal of weeds which act as alternate hosts. Eg. Paddy gall fly Orseolia oryzae breeds on grasses such as Panicum sp.
Cynodon dactylon etc.
Fruit sucking moth larvae Eudocima ancilla on weeds of Menispermaceae
iii) Systematic cutting and removal of infested parts: Keeps down subsequent infestation.
Eg. Removal of sugarcane shoots affected by borers,
Cutting and removal of infested parts of brinjal attacked by Leucinodes orbonalis Pruning of dried branches of citrus eliminates scales and stem borer.
Clipping of tips of rice seedlings before transplanting eliminate the egg masses of stem borer.
Clipping of leaflets in coconut reduces the black-headed caterpillar Ploughing and hoeing help to burry stages of insects or expose soil inhabiting insects to be picked up by birds. Pests like coccids get carried over to the next season through stubbles, which should be promptly removed.
- iv) Changes in the system of cultivation :
Change of banana from perennial to annual crop reduced the infestation of banana rhizome weevil Cosmopolitus sordidus in addition to giving increased yields. Avoiding ratoon redgram crop during offseason helps in reducing the carryover of pod fly Melangromyza obtusa and eriophyid mite Aceria cajani.
- v) Crop rotation: Crop rotation is most effective practice against pests that have a narrow host range and dispersal capacity. Lady’s finger followed by cotton will suffer from an increased infestation of pests. Hence if a non-host crop is grown after a host crop, it reduces the pest population.
Eg. Cereals followed by pulses.
Cotton should be rotated with non-hosts like ragi, maize, rice to minimize the incidence of insect pests.
Groundnut with non-leguminous crops is recommended for minimizing the leaf miner incidence.
- vi) Mixed cropping: Intended for getting some return when one crop is attacked, the other escapes.
Eg. Garden peas and sunhemp
vii) Growing resistantvarieties: certain varieties resists pest attack .
Eg: GEB-24 and MTU–5249 resistance to paddy BPH, Surekha variety to gall
midge, TKM -6 and Ratna for stem borer.
(B) Integrated Pest Management Strategies – Cultural practices specially adopted for certain pests
- Adjusting planting or sowing or harvesting times to avoid certain pests: The manipulation of planting time helps to minimize pest damage by producing asynchrony between host plants and the pest or synchronizing insect pests with their natural enemies.
Eg. Early planting of paddy in Kharif and late planting in rabi minimize the infestation of rice stem borer.
Delaying the sowing of sunhemp till the onset of South West Monsoon avoids sunhemp hairy caterpillar (Utethesia lotrix) attack.
Early sown sorghum in kharifreduces the infestation of shoot fly
Timely and synchronous planting has been found to reduce bollworm damage in cotton and stem borer damage in sugarcane.
- Trap cropping: Growing of susceptible or preferred plants by important pests near a major crop to act as a trap and later it is destroyed or treated with insecticides. Trap crop may also attract natural enemies thus enhancing natural control.
Eg: Trap crop Main crop Insect pest; Castor Chillies Tobacco caterpillar Spodoptera litura; Tomato Citrus Fruit sucking moths Otheris spp; Marigold Cotton American bollworm Helicoverpa armigera.
- Trimming field buds: Grasshopper eggs, which are laid in field bunds are destroyed by trimming field bunds
- Flooding the field: Flooding of fields is recommended for reducing the attack of cutworms, armyworms, termites, root grubs etc.
Eg: For cutworms like paddy swarming caterpillar (Spodoptera mauritinana and S. exiqua) and ragi cutworm by flooding the fields caterpillars float and leave the plants.
- Draining the fields: In case of paddy case worm Nymphula depunctalis which travel from plant to plant via water. it can be eliminated by draining or drying the field.
Draining the rice fields for 3-4 days during infestation controls BPH and whorl maggot.
Alternate drying and wetting at 10 days interval starting from 35 DAT reduces the BPH and WBPH.
- Alleyways: Formation of alleyways for every 2m in rice field reduces the BPH Nilaparvata lugens
(C) Integrated Pest Management Strategies – Other cultural methods
- Root weevil, Echinonemus oryzae damage in rice can be overcome by applying 20 kg ammonium sulphate and 40 kg single super phosphate in rice.
- Raking up and hoeing of the soil around gourds, mango and other fruit trees serves to destroy pupae of fruit flies.
- Adaptation of high seed rate in sorghum and later removal and destruction of shoot fly (Atherigona soccata) affected ones.
- Trash mulching @ 3 t/ha 3 days after planting or earthing up at a month or two after planting minimize early shoot borer ( Chilo infuscatellus) attack in sugarcane.
- Destruction of crop residue: Stubbles of sugarcane and paddy that harbour borers should be ploughed up and burnt.
- Deep ploughing in summer exposes most of the soil-inhabiting insects to the sun and hot winds and get them killed.
- Periodical drying of stored produce against stored grain pests.
- Pruning of dried twigs/ branches to eliminate pests like scales and orange borer.
Mechanical Methods of Pest Control In Integrated Pest Management Strategies
Reduction or suppression of insect pest population by means of manual devices or labour.
Hand picking and collection with hand nets and killing insects: Handpicking is a most ancient method which can prove fairly effective under certain conditions. Egg masses, larvae or nymphs and sluggish adults can be handpicked and destroyed.
Eg. Egg masses of paddy stem borer (Scirpophaga incertulas) and groundnut hairy caterpillar
– Early stages of Spodoptera litura and hairy caterpillars are easily located by their typical damage symptoms
– The moringa caterpillars, which collect at tree trunks in the mornings can be burnt.
– Most of the insects can be collected with hand nets and destroyed.
– Collection and destruction of fallen fruits are effective against fruit flies and fruit borers.
Provision of preventive barriers: Digging of 30 -60 cm wide and 60 cm deep trenches or erecting 30 cm height tin sheets barriers around the fields is useful against pests like hairy caterpillars.
Bagging/wrapping of pomegranate and mango fruits in paper bags avoids the infestation of pomegranate butterfly Virachola Isocrates and mango fruit fly Bactrocera dorsalis
Tin bands are fixed over coconut palms to prevent damage by rats.
Integrated Pest Management Strategies – Other mechanical methods
- Extraction of adult Rhinoceros beetle (Oryctes rhinoceros) from the crown of coconut trees using an arrow-headed rod/hook.
- Construction of rat proof godowns
- Use of an alkathene band around the tree trunks of mango to check the migration
of first instar nymphs of mealybugs and red ants
- Sticky bands around tree trunks against red tree ant (Oecophylla samaragdina)
- The systematic shaking of root grub adults harbored trees during evening hours to dislodge and destroy by dumping in the fire.
- Shaking ofredgram plantsto collect and destroy later instars of Helicoverpa armigera
- Shaking the trees and bushes by which the insects fall to the ground and they can be collected
Physical And Legislative Methods Of Pest Control In Integrated Pest Management Strategies
- II) Physical Methods of Pest Control: Use of certain physical forces to minimize the pests
– A material called drie-die, consist of highly porous, finely divided silica gel which when applied abrades the insect cuticle thus encouraging loss of moisture resulting in death. It is mainly used against stored product pests.
– Kaolinic clay after successive activation with acid and heat can be mixed with stored grain. The clay minerals absorb the lipid layer of the insect cuticle by which the insects lose their body moisture and die due to desiccation. Artificial heating and cooling of stored products will prevent insect damage. Usually, high temperatures are more effective than low temperatures.
– Stored products can be exposed to 550C for 3 hours to avoid stored product pests
– Steam sterilization of soil kills soil insects
– Vapour Heat Treatment (VHT): Heated air is saturated with water (>RH 90%) for a specified period of 6 to 8 hours for raising pulp temperature to 43-44.5°C in case of mango against fruit flies.
– Oxygen stress and carbon dioxide concentration: In airtight containers, a small volume of air is enclosed, the available oxygen is quickly utilized by insects and raise the concentration of carbon dioxide. High concentration of carbon dioxide leads to the death of stored products insects.
– Male insects can be made sterile by exposing them to gamma radiation or by using chemicals. When sterile males are released in a normal population they compete with normal males in copulation and to that extent, the reductive capacity of the population is reduced. By sterilizing the pupae of screwworm, livestock pest (Cochliomyia hominivorax) with radiations, sterile males were obtained. They were released @ 400/sq mile for 7 weeks. By this method, total eradication was achieved in South East parts of America and in the Curacao islands in case of screwworm.
– Light traps are arranged for attracting the insects, which are trapped by keeping water or oil in a container or a killing bottle below the light trap. Light traps are useful for monitoring the population of important insect pests in an area. Eg: Most of the moths and beetles.
– Flamethrower is a compressed air sprayer with kerosene oil for producing flames. There is a lance, which is fitted with a burner. When the burner is heated, the kerosene oil is released and it turns into flames. Used for burning locust populations, the congregation of caterpillars, patches of weeds etc.
Integrated Pest Management Strategies – Legislative / Legal / Regulatory Methods of Pest Control
In early days there were no restrictions on the transport of plants and animals from one country to another since the danger involved in it is not realized, which resulted in the introduction of pests from one country to another. In many countries, many of the dangerous pests have frequently been found to be foreign pests and they inflict greater damage than the indigenous ones. Potato tuber moth Pthorimea operculella, cotton cushiony scale Icerya purchasi, wooly aphis on apple Eriosoma lanigerum, San Jose scale Quadraspidiotus perniciosus, golden cyst nematode Globodera rostochinesis and the giant African snail ,Achatina fulica (Predatory snail Eugladina rosea) , serpentine leafminer Liriomyza trifolii, Spiralling whitefly, Alerodicus dispersus , Coconut mite Aceria guerreoronis etc,are some exotic pests introduced into our country.
The legislative measures in force now in different countries can be grouped into five classes. They are,
- Legislation to prevent the introduction of new pests and weeds etc from foreign countries (International quarantine)
- Legislation to prevent the spread of already established pests, diseases and weeds from one part of the country to another (Domestic quarantine)
- Legislation to enforce upon the farmers regarding the application of effective control measures to prevent damage by already established pests.
- Legislation to prevent the adulteration and misbranding of insecticides and determine their permissible residue tolerance levels in foodstuffs and
- Legislation to regulate the activities of men engaged in pest control operations and application of hazardous insecticides.
Biological Control In Integrated Pest Management Strategies
The successful management of a pest by means of another living organism (parasitoids, predators, and pathogens) that is encouraged and disseminated by man is called biological control. In such programme the natural enemies are introduced, encouraged, multiplied by artificial means and disseminated by a man with his own efforts instead of leaving it to nature.
Integrated Pest Management Strategies – Techniques in biological control
Biological control practices involve three techniques viz., Introduction, Augmentation, and Conservation.
- Introduction or classical biological control: It is the deliberate introduction and establishment of natural enemies to a new locality where they did not occur or originate naturally. When natural enemies are successfully established, it usually continues to control the pest population.
- Augmentation: It is the rearing and releasing of natural enemies to supplement the numbers of naturally occurring natural enemies. There are two approaches to augmentation.
- Inoculative releases: a Large number of individuals are released only once during the season and natural enemies are expected to reproduce and increase its population for that growing season. Hence control is expected from the progeny and subsequent generations and not from the release itself.
- Inundative releases: It involves mass multiplication and periodic release of natural enemies when pest populations approach damaging levels. Natural enemies are not expected to reproduce and increase in numbers. Control is achieved through the released individuals and additional releases are only made when pest populations approach damaging levels.
- Conservation: Conservation is defined as the actions to preserve and release of natural enemies by environmental manipulations or alter production practices to protect natural enemies that are already present in an area or non-use of those pest control measures that destroy natural enemies.
Parasite: A parasite is an organism which is usually much smaller than its host and a single individual usually doesn’t kill the host. The parasite may complete their entire life cycle (eg. Lice) or may involve several host species. Or Parasite is one, which attaches itself to the body of the other living organism either externally or internally and gets nourishment and shelter at least for a shorter period if not for the entire lifecycle. The organism, which is attacked by the parasites, is called hosts.
Parasitism Are the phenomena of obtaining nourishment at the expense of the host to which the parasite is attached.
The parasitoid is an insect parasite of an arthropod, parasitic only in immature stages, destroys its host in the process of development and free-living as an adult. Eg: Braconid wasps.
Qualities of a Successful Parasitoid in Biological Control Programme
A parasitoid should have the following qualities for its successful performance.
- Should be adaptable to environmental conditions in the new locally.
- Should be able to survive in all habitats of the host.
- Should be specific to a particulars sp. of the host or at least a narrowly limited range of hosts.
- Should be able to multiply faster than the host.
- Should be having more fecundity.
- Life cycle must be shorter than that of the host.
- Should have high sex ratio.
- Should have the good searching capacity for the host
Some successful examples:
- Control of cottony cushion scale, Icerya purchasi on fruit trees by its predatory vedalia beetle, Rodolia cardinalis in Nilgiris. The predator was imported from California in 1929 and from Egypt in 1930 and multiplied in the laboratory and released. Within one year the pest was effectively checked.
- For the biological suppression of Water Fern, Salvinia molesta, the weevil, Cyrtobagous salviniae, was imported from Australia in 1982. Exotic weevil, C. salviniae was released for the control of water fern, S. molesta in a lily pond in Bangalore in 1983-84. Within 11 months of the release of the weevil in the lily pond, the Salvinia plants collapsed and the lily growth, which was suppressed by competition from salvinia resurrected.
- Biological Control of Water Hyacinth, Eichhornia crassipes, three exotic natural enemies were introduced in India viz., hydrophilic weevils – Neochetina bruchi and N. eichhorniae ( Argentina) and galumnid mite Orthogalumna terebrantis (South America) in 1982 for the biological suppression of water hyacinth.
Microbial Control In Integrated Pest Management Strategies
Microbial control refers to the exploitation of disease-causing the organism to reduce the population of insect pest below the damaging levels. Steinhaus (1949) Coined the term ‘Microbial Control’ when microbial organisms or other products (toxins) are employed by man for the control of pests on plants, animals or man.
- Bacteria: More than 100 pathogenic bacteria were recorded of which i. Bacillus thuringiensis (B.t.) is important and is isolated from flour moth, Ephestia kuhniella by Berliner (1915) B.t. known as a bacterial insecticide is now being using by farmers mostly on lepidopterous larvae. It can infect more than 150 species of insects. The entry of the bacteria is by ingestion of the bacteria, which infect the midgut epithelial cells and enter the haemolymph to sporulate and cause septicemia.
Properties of B.t.
- Highly pathogenic to lepidopterous larvae.
- Non-toxic to man.
- Safer to beneficial insects.
- Compatible with a number of insecticides.
- So far no resistance is developed in insects.
- Synergistic in combination with certain insecticides like carbaryl.
- Available in different formulations(Trade names Thuriocide, Delfin, Bakthane, Biobit, Halt, Dipel etc).
- Formulation is so standardized that 1 gm of concentration spore dust contains 100 million spores
Bacillus popillae (available as Doom) causes milky disease on Japanese beetle, Popillia japonica
- Viruses: NPV (Borrellina virus): About 300 isolates of the Nuclear polyhedral virus have been isolated from the order Lepidoptera. Among these viruses Baculoviruses (Baculoviridae) are successful in IPM. The NPV is observed to affect 200 species of insects like Corcyra cephalonica, Pericallia ricini, Amsacta albistriga, Spodoptera litura, Heliothis armigera etc., by ingestion. The virus infected dead larvae hanging upside down from plant parts (Treetop disease). The cuticle becomes fragile, rupturing easily when touched, discharges liquefied body fluids. NPV multiplies in insect body wall, trachea, fat bodies and blood cells. The polyhedra are seen in nuclei. The polyhedral bodies enlarge in size destroying the host nuclei to get released into the insect body cavity.
Fungi: The fungal disease occurrence in insects is commonly called as mycosis. Most of the entomopathogenic fungi infect the host through the cuticle. The process of pathogenesis begins with
- Adhesion of fungal infective units or conidium to the insect epicuticle.
- Germination of infective units on cuticle.
- Penetration of the cuticle.
- Multiplication in the haemolymph
- Death of the host (Nutritional deficiency, destruction of tissues and releasing toxins).
- Mycelial growth with the invasion of all host organs.
Specific requirements for successful commercial production and use of entomopathogenic fungi as myco insecticides are
- The fungal isolate selected for mass production or commercialization should possess rapid growth, high pathogenicity to target pests and sporulate profusely.
- A simple medium with cheap and easily available components should be developed.
- The production procedure should be easy and also keep the production costs low.
- Formulation with long shelf life at room temperature without any loss of infectivity and viability for at least for 12 – 18 months More than 5000 species of entomopathogenic fungi are recorded. Important species are Entomophthora, Metarhizium, Beauveria, Nomuraea, and Verticillium.
Eg: Entomophthora grylli on grasshoppers; Aspergillus flavus on Epilachna beetles; Spicaria sp. on castor whitefly: Metarhizium anisopliae (Green muscardine) on Orthoptera, white muscardine, Beauveria bassiana on Leptinotarsa decemlineata.
Protozoa: Their mass production is difficult. They infect insect orders like Lepidoptera,
Coleoptera, Orthoptera, Hemiptera and Diptera.
Eg: Farinocystis triboli on Tribolium castaneum, Malpighamoeba locustae on grasshoppers and Nosema bombycis (Pebrine disease) on silkworms. Here it is harmful since silkworm is a productive insect.
Entomopathogenic nematodes (EPNs)
Nematodes about 1000 species are known to attack insects. Especially Rhabditids (Rhabditidae) are found to have a symbiotic relationship with the bacteria, forming a disease complex. The best-known disease complex was discovered by Dutky and Hough in 1955 in the caterpillars of the Codling moth, Cydic pomonella on apple.
The complex is known as DD-136 by the nematode itself is often called so. The nematode involved was Neoaplectana carpocapsae (also known as Dutky nematode) and the bacterium Achromobacter nematophilus.
Chemical Control In Integrated Pest Management Strategies
Control of insects with chemicals is known is chemical control. The term pesticide is used to those chemicals which kill pests and these pests may include insects, animals, mites, diseases or even weeds. Chemicals which kill insects are called as insecticides.
The insecticide may be defined as a substance or mixture of substances intended to kill, repel or otherwise prevent the insects. Similarly, pesticides include nematicides – which kill nematodes, miticides or Acaricides which kill mites, Rodenticides – which kill rats, weedicides- that kill weeds, Fungicides- that kill fungus etc.
Integrated Pest Management Strategies – Importance of chemical control
Insecticides are the most powerful tools available for use in pest management. They are highly effective, rapid in curative action, adaptable to most situations, flexible in meeting changing agronomic and ecological conditions and economical.
Insecticides are the only tool for pest management that is reliable for emergency action when insect pest populations approach or exceed the economic threshold. A major technique such as the use of pesticides can be the very heart and core of integrated systems. Chemical pesticides will continue to be essential in the pest management programmes.
There are many pest problems for which the use of chemicals provides the only acceptable solution. Contrary to the thinking of some people, the use of pesticides for pest control is not an ecological sin. When their use made on sound ecological principles, chemical pesticides provide dependable and valuable tools for the biologist.
Their use is indispensable to modern society.
Integrated Pest Management Strategies – General Properties of Insecticides
- Pesticides are generally available in a concentrated form which is to be diluted
and used except in ready to use dust and granules.
- They are highly toxic and available in different formulations.
Integrated Pest Management Strategies – Properties of an ideal insecticide or pesticide
- It should be freely available in the market under different formulations.
- It should be toxic and kill the pest required to be controlled.
- It should not be phytotoxic to the crops on which it is used.
- It should not be toxic to non-target species like animals, natural enemies etc.
- It should be less harmful to human beings and other animals.
- Should not leave residues in crops like vegetables.
- It should have the wide range of compatibility.
- It should not be toxic to bees and fish and other beneficial organisms.
- It should have higher tolerance limits.
- Should possess quick known down effect.
- Should be stable on the application.
- Should not possess tainting effects and should be free from offensive odor.
- Should be cheaper.