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Lectures in: (IPM) Integrated Pest Management (Course # 94432). Prepared by Prof. Yacoub Batta Department of Plant Production & Protection Faculty of Agriculture An- Najah National University
Department of Plant Production & Protection
Faculty of Agriculture
An-Najah National University
Nablus, West Bank, Palestine
Faculty of Agriculture
Department of Plant Production & Protection
* Pests may be found within a broad assemblage of organisms that includes insects, plant pathogens and weeds.
* Some insect pests serve as vectors of diseases caused by bacteria, filarial nematodes, protozoans & viruses.
* Pests’ densities could be regulated by density-independent factors such as temperature& precipitation or rainfall. Biotic factors within a pest’s life system also may serve as important factor in population regulation such as interaction with predators & parasitoids of the intended pest.
* Some ecologists add the competition (interspecific &/or intraspecific) as a limiting factor for the density & distribution of organisms including pests.
* Non-reasoned use of insecticides in pest management led to many significant ecological backlashes (e.g. insecticide resistance, concentration of chlorinated hydrocarbon insecticides in the food chain, significant decline in densities of natural enemies populations, secondary outbreaks of pests etc.).
* First, in 1959, entomologists of the University of California stated the following concept towards the IPM application: chemical and biological control of spotted alfalfa aphid could be integrated during the control of this pest.
* After that date, many terms & concepts were developed by Entomologists, plant pathologists and weed scientists and by IPM practitioners such as:
1- Economic Injury Level (EIL) which is the lowest population density that will cause economic damage to host plant(s).
2- Economic Threshold (ET) which is the density at which control measures should be determined to prevent an increasing pest population from reaching the economic injury level.
3- General Equilibrium Position (GEP) which is the average density of a population over a period of time (usually lengthy) in the absence of permanent environmental changes
4- Integrated control (IC): is applied pest control that combines & integrates biological & chemical control measures and employs the
use of ET to determine when chemical control should be utilized to prevent pests from reaching the EIL.
* The integrated control concept has evolved into the IPM concept that includes insects, plant pathogens, weeds and vertebrate pests.
* Knats & Downs (1979) indicated that IPM should interdisci-plinary approach rather than simply combining various control options within one discipline because weeds harbour insects and diseases whereas, diseases may kill insects and weeds.
* In the last century, some debate persisted among academics regarding the differences between “pest management” and “integrated control” where Kogan (1998), Smith & Reynolds (1966) believed that integrated pest control must integrate all control procedures and production practices into an ecologically based system approach aimed at producing high quality products in a profitable manner .
* Administration & enforcement of the federal pesticides act be transferred from the USDA to newly created EPA, this resulted in
policies aimed at reducing environmental & human health and safety risks that are linked with pesticides use so popularization of IPM took place by incorporation of “Integrated Pest Management” and its acronym IPM into the English literature & accepted by the scientific community.
* Key points regarding IPM reached on (Kogan, 1998):
1- Integration meant that harmonious use of multiple methods to control single pests as well as the impacts of multiple pests;
2- Pests were any organism detrimental to humans, including vertebrate & invertebrate animals, pathogens and weeds;
3- IPM was a multidisciplinary endeavour;
4- Management referred to a set of decision rules based on ecological principles and economic and social considerations.
* Finally, development of “IPM Road Map” by the USDA with the ultimate objective of increasing of IPM implementation by practitioners (e.g. land managers, public and wildlife health
* The IPM Road Map (2003) offers a definition of IPM that includes the historical elements of IPM reviewed by Kogan (1998). Some extension of this concept was done afterwards to focus on reducing the risks of economic & environmental losses.
* Within the IPM Road Map (2004), IPM was defined as a long-standing, science-based, decision-making process that identifies and reduces risks from pests and pest management related strategies so that IPM serves as an umbrella to provide an effective, all encompassing, low-risk approach to protect resources and people from pests.
* “Pest Management Strategy” is the total approach used to eliminate or reduce a real or perceived pest problem.
* Development of a particular strategy is influenced by the biology & ecology of the pest & its interaction with a host or environment.
* 4 types of strategies could be developed based on pest characteristics & economics of management (Pedigo & Rice, 2006):
1- Strategy of “Doing nothing”
2- Strategy of “Reducing pest numbers”
3- Strategy of “Reducing host susceptibility to pest injury”
4- Strategy of “Combining reducing pest population with Reducing host susceptibility to pest injury”
* After choosing certain strategy, methods of implementing such strategy can be also chosen. These methods are called “pest management tactics”.
**Strategy of “Do-nothing”: Host plants or animals are able to tolerate small amounts of injury without suffering economic
damage. If the pest density is below the ET, then the do-nothing strategy is the correct approach. The do-nothing strategy is used when insects cause indirect injury to a host or when a successful pest management program reduces the pest population and only surveillance of the remaining population is necessary. No tactics are used in the do-nothing strategy but certain effort should be exerted to accomplish the pest suppression.
** Strategy of “Reducing pest numbers”: It is the most frequently used strategy in pest management when the pest densities reach higher levels. It is often employed in a therapeutic manner when pest populations reach the ET or in a preventive manner.
* Two objectives are in this strategy:
1- to diminish the population peaks of the pest if the pest’s long-term average density or general equilibrium density is low compared with the ET. This will prevent damage occurring during pest outbreaks.
2- to lower the general equilibrium position so the highest peak
populations never reach the ET. This could be done if the pest population’s general equilibrium position is near or above the ET. Therefore, the inherited reproductive and/or survival potential of the population is reduced. Many tactics can be used for reducing pest numbers such as using resistant hosts; applying insecticides, pheromones, mechanical trapping, natural enemies and insect growth regulators; the release of sterilized insects and modification of the environment.
** Strategy of “Reducing host susceptibility to pest injury”: is one of the most environmentally compatible strategies that does not modify the pest population but instead, it changes the host or host’s relationship and interaction with the pest to make it less susceptible to a potentially damaging pest population. A common form of this strategy is where plant cultivar are developed with a type of resistance (known as tolerance). The tolerance expressed by a plant does not usually reduce the attack by a pest population but the injury caused (i.e. yield loss) become less than it does on a similar non tolerant plant. Another component of this strategy is
the ecological modification of factors influencing the distribution & abundance of pest. As example of this strategy is adjusting of crop planting date to create an asynchrony between the pest & the susceptible plant stage.
** Strategy of “combining reduced pest populations with reduced host susceptibility”: is the strategy that combines the objectives of the previous strategies in a logical step towards the development of pest management program. Previous experience has shown that a single strategy is more likely to fail when either, slowly or quickly, a single tactic approach is used. With the multiple approach, if one tactic fails, the other operates to help modulate losses. The use of multiple strategies & tactics is the basic principle in developing an IPM program.
In the USA and since 1970, research and extension for the IPM programs is assured by the USDA, EPA & NSF (National Science Foundation). The majority of these programs are conducted by granted investigators in the American Universities. Two of the most pilot efforts in this respect included: 1) Huffaker (1972-1979) with 13 m Dollars funded by the USDA, EPA & NSF); 2) Adkisson (1979-1984) with 15 m Dollars funded by the USDA & EPA).
* Huffaker’s program of IPM concentrated on the development of IPM tactics for insect pests in cotton, soybean, alfalfa, citrus, pome and stone fruits whereas, Adkisson’s program of IPM expanded its range of targeted pests to include diseases, insects & weeds in alfalfa, apples, cotton & soybean.
* In 1978, a USDA report from “The extension Committee on Organization & Policy of IPM” recommended that 58 m Dollars be spent on extension of IPM programs but only 7 m Dollars were spent in 1980s and 9.86 m Dollars until the year 2006.
* Funding of IPM research & implementation programs in develo-
ping countries is increasingly important as food production & environmental concerns. There are some key organizations & programs that fund and promote these IPM efforts include: FAO (Food and Agricultural organization) of the United Nation; UNEP (United Nations Environment Program); UNDP (United Nations Development Program).
* In 1995, the global IPM facility was established in the FAO headquarters in Rome, Italy. The co-sponsors of the facility include FAO, UNDP, UNEP and the World Bank. The impact of the Global IPM facility has been assessed as “mixed”.
* Other key organizations that fund & promote IPM globally include “The Integrated Pest Management Collaborative Research Support Program or IPM-CRSP”. This program was started in 1993 with the financial assistance of the US Agency for international development (USAID). Now, it has many sites around the world: Albania, Bangladesh, Ecuador, Guatemala, Jamaica, Mali, Philippines & Uganda.
* Successful IPM programs that have been developed through this effort are: rice & vegetable cropping systems in the Philippines; maize & bean cropping systems in Africa; horticultural export crops in Lain America; Sweet potato production in the Caribbean.
* Consultative Group on International Agricultural Research (CGIAR) centers that support the implementation of systemwide programs on IPM in several international “target zones” such as Africa, Asia & Latin America.
* The US Council on environmental Quality (1972) described IPM as “an approach that employs a combination of techniques to control the wide variety of potential pests that may threaten crops”. It suggests numerous economic pests that can be managed by “maximum reliance” on natural pest controls with the incorporation of key elements including cultural methods, pest-specific diseases, resistance crop varieties, sterile insects and attractants together with the use of biological control and reduced risk, species-specific chemical controls as part of an IPM program.
* In September 1993, the US Congress during Clinton Admin-stration set a goal for 75 % implementation of IPM practices by the year 2000 on managed agricultural areas in the USA. A national Agricultural Statistical Service (2001) report indicated that by the year 2000, IPM adoption levels for many crops had met or exceeded this goal.
* Bajwa & Kogan (2003) provided a very good assessment of IPM adoption in Africa, Americas (other than USA), Asia, Australia,
Europe and USA for many crops. The % of farmers who have adopted IPM practices is very high in many cases such as pear production in Belgium (98 %), cotton production in Australia (90 %), pome fruits in BRITISH Columbia (75 %), sugarcane produ-ction in Columbia (100 %).
* Despite these advances in IPM implementation, pesticide usage has increased in many developing countries throughout 1990s7 remains the exclusive tactic to control pests. Bajwa & Kogan (2003) remind us that “IPM is a tangible reality in some previleged regions of the world but still remains a distant dream for many others”.
1- Control of Prickly Pear Cactus in Australia: Prickly pears or prickly pear cactus (Optuntia spp.) is native to Americas but it become serious invasive weeds in suitable habitats around the world. In 1840, it was introduced into Australia (State of Queensland) to be used as a hedge around fields, gardens etc. The climate & soil of eastern Australia was ideal for prickly pear cactus growth so the weed spread quickly and the framers in 1880s tried to control the weed but without success and in 1893, it was then declared as a noxious weed in Queensland.
* In 1913, prickly pear cactus was estimated to cover 1.4 m ha with a dense infestation & another 4.9 m ha with scattered infestation. By 1924, it had infested 24 m ha in Queensland & New South Wales (spread at a rate of 1 m ha annually). Attempts at controlling the prickly pear were made using different control measures (e.g. mechanical, chemical and cultural methods) but all these measures have failed to stop the spread of the weed.
* In 1927, an imported phytophagous insect from south America called cactus moth (Cactoblastis cactorum) was introduced into the infested areas with prickly pears. Over 220 m eggs of the insect were distributed over two hundred thousands ha of prickly pear cactus that were completely destroyed by the insect larvae . The insect was rapidly spread and at the end of 1931, millions of hectares of prickly pears were completely destroyed and thus the biological control as a part of an IPM program was succeeded in eradication of the weed.
* As a conclusion, the land that had been useless for decades was cleared and restored to range-land & agricultural production. This is one of the most successful biological control campaigns ever mounted against the pest.
2- Screwworm eradication in North & Central America: Sterile insect technique was used for eradication of this insect pest
(Screwworm: Cochliomylahominivorax) from the USA, Mexico and Central America. This insect attacks livestock and occasionally attacks humans. The female adult lays 450 eggs in an open wounds where the larvae feed on tissues and enlarge the wound. Heavily attacked livestock may be killed within 10 days. A severe pest outbreak occurred in southern USA in 1935 with 1.2 m cases of infestation & one hundred eighty thousands of livestock deaths.
* The sterile insect technique involves the intentional release of large numbers of sterilized insects to compete with wild insects for mates. In screwworm, emerged adults of this insects (males & females at 5 days old) were irradiated with cesium so they become sterile. The technique was applied, in the first step, to livestock in Florida & Southern Georgia and Alabama in 1958 and > 200 m sterilized flies of screwworm were released from airplanes during an 18-month period resulting in a complete eradication of the insect from the region. The same was done in Southwest USA until the Mexican borders in 1960s and in Mexico itself in 1970s that declared free of screwworm in 1986. The fly-free zone was
continually moved south resulting in eradication of this insect from numerous Central American Countries. This indicate the success of this technique as one of the IPM techniques in controlling of this insect pest.
3- Termite control in North America: Termites are destructive insect pests of wooden structures. Estimates place the annual cost of damage and treatment at 5000 m Dollars worldwide.
* Termite control generally consists of 5 types of treatment programs (as parts of IPM of this insect): liquid termiticides, bait systems, wood preservatives, mechanical barriers & biological termiticides. Each type of program has its advantages & disadvantages but the bait system is the most novel as it uses an insect growth regulators to control the termite colony.
* The bait system is a relatively new tool for termite control. Inst-ead of applying a chemical barrier to exclude the insects from a wooden structure, these insects are offered food in form of baits.
* The treatment bait have 2 components: 1) a termite food source (block of wood in the soil) and a slow-acting termiticide (often an insect growth regulator such as diflubenzuron, hexaflumuron or noviflumuron). This insect growth regulator is a slow-acting, non-repellent toxicant that prevents the formation of chitin in the insect cuticle.
* Termites feeding on the bait are not killed immediately but through colony recruitment when worker termites find the bait, the insect growth regulator is passed to other colony members , ultimately leading to decline or perhaps elimination of the colony. The advantage of bating is that the system is not-intrusive, consumer friendly, safer than most of the soil-applied insecticides, especially targets termites and dramatically reduces the amount of chemical needed to protect a structure. However, a disadvantage is that the process may take weeks or months to knock down termite population.