Dennis Ring | 3/23/2005 11:28:32 AM
Integrated pest management (IPM) is a term that is used widely and has different meanings to different people. Before defining IPM, we will define the term pest. Pests do not exist in nature, but rather the term is a label used by humans to characterize organisms that have undesirable consequences and compete with humans for a resource (Luckman & Metcalf 1994). Consequently, IPM may be defined as the intelligent selection, integration and use of actions to manage a pest while attempting to achieve favorable economic, ecological and sociological consequences (Rabb 1972). Favorable economic consequences regarding protection of a structure from termites (one group of wood-destroying organisms) include paying the least costs over the life of a structure in efforts to protect it. Favorable ecological consequences include protecting other organisms and providing a sustainable environment. Favorable sociological consequences include protecting human health and satisfying the desires of humans.
Integrated pest management does not exclude insecticides nor is it based exclusively on insecticides. Rather, IPM may use insecticides as one tool among many and integrate the tools to mitigate the negative impacts of insects.
Termites and other wood-destroying organisms (wood-destroying beetles, wood-decaying fungi and marine borers) have an important role in nature -- they decompose wood and plant materials, recycling nutrients back into the environment for plants to grow. In the urban environment, however, termites and other wood-destroying organisms are largely undesirable. They can cause significant economic loss, injure trees, require broad use of insecticides and interrupt peoples' lives.
The problem of managing wood-destroying organisms is complex. It impacts not just the homeowner but also the builders that build the homes, real estate agents that are involved in selling homes, banks and mortgage companies that lend on the value of homes, insurance companies that depend on the durability of homes to withstand catastrophic events, building materials suppliers that sell wood and other building products, the state and federal governments that are given the responsibility to protect the welfare of their citizens, as well as architects, pest management professionals, the forestry industry, the nursery industry, landscapers, building code inspectors and so on.
There is no “magic bullet” for this problem! It requires the use of several tools integrated into a comprehensive, long-term, multi-tactic IPM approach over large areas to develop a sustainable solution. Cooperation is needed from everyone, on every aspect of a structure from site preparation, planning, designing, building and pest management to occupying and maintaining the structure over its life. Everyone has a responsibility to protect a structure. Actions taken at each stage during the lifetime of a structure will impact its ability to withstand the pressure from termites and other wood-destroying organisms. Any solution must protect all wood and cellulose materials such as structural wood components, interior moldings, doors, wall board, cabinets and furnishings, but the need is particularly important for structural and hidden building components where damage can occur undetected and the consequences can be devastating.
In Louisiana and in the United States, management of termites has relied heavily on soil treatment. Losses caused by the Formosan subterranean termite indicate that a greater emphasis on IPM is needed.
Su (1994) estimated the annual cost of controlling termites to be $1.5 billion in the United States. In 1993 the Wood Protection Council of the National Institute of Building Sciences estimated the annual costs of replacing wood damaged by termites to be $2 billion, up from $750 million in 1988 (Anonymous 1993). These costs must be greater today. The Formosan subterranean termite is thought to cause $1 billion a year in losses in the United States. It is thought to be the most destructive insect in Louisiana, negatively affecting the economy and wealth of the state. This is despite the fact that its presently known range does not include the entire state but mainly parishes south of Interstate 10 and 12 (Hu et al. 2000). Also, it is not widely distributed in all of these parishes. Estimates of losses each year are $300 million in New Orleans and $500 million in Louisiana.
The Formosan subterranean termite is a very aggressive termite. It finds other sources of water when the soil is treated, and it builds carton nests above ground in walls and other places (Potter 1997). The Formosan subterranean termite eats the centers of creosote-treated railroad ties, wharves and telephone poles (Potter 1997). Ninety percent of the creosote-treated wood from a saltwater dam in Lake Charles was replaced 19 years after it was built due to feeding by the Formosan subterranean termite. It will go through thin sheets of soft metal, mortar, PVC pipe, electric power lines and telecommunications lines (Henderson and Dunaway 1999). The Formosan subterranean termite was discovered eating bagasse used in expansion joints between units of flood walls in New Orleans. This is expected to result in small leaks in the event of a flood.
In spite of management attempts, the Formosan subterranean termite is causing severe economic losses to property. One house has split apart in New Orleans. Other houses were demolished because of structural damage caused by the Formosan subterranean termite. An apartment complex was demolished 17 years after it was built due to damage by this termite. Another house was demolished and rebuilt using pressure treated wood because several attempts to control the Formosan subterranean termite had failed. People are defaulting on loans because they do not have the money and can’t get loans to repair their homes after damage by the Formosan subterranean termite. For others the Formosan subterranean termite has caused thousands of dollars in repair and treatment costs and disruption of their lives.
The Formosan subterranean termite is expanding its range in the state by the actions of humans and natural means. Thus, we can expect economic losses from this insect to continue to increase, leading to a greater drain on the state’s economy. If the current trends are pushed to their logical conclusion, the Formosan subterranean termite will spread throughout the state, increasing the damage to properties, increasing the numbers of loan defaults, reducing wealth and increasing demands on government. To interrupt this cycle, we must start building structures incorporating IPM of wood-destroying organisms and start implementing better solutions for protecting existing structures.
One of the most important investments in a person’s life is a house. Presently, this is at risk from the Formosan subterranean termite. If a structure is weakened by Formosan subterranean termite attack, the structure is at a greater risk of collapsing, resulting in increased safety risk and economic loss.
The Formosan subterranean termite infests live trees. Weakened trees are susceptible to being blown over in high winds and possibly falling on homes, structures, cars, other property, roads or people.
It is not possible to eradicate the Formosan subterranean termite from Louisiana at this time, so we have to learn to manage it in our environment. This can be done by adopting a statewide integrated pest management program encompassing all aspects of termite management. The program must address short-term needs and long-term (approaching a geologic view of time) management and prevention. If long-term management and prevention are not implemented, then treatments for short-term needs will only delay further economic losses, and the money used for short-term treatments may be viewed as wasted. The longer an integrated pest management program is delayed, the greater and more costly the problem will be. Prevention of wood-destroying organisms should be considered along with other factors in all building designs and practices.
Integrated pest management of wood-destroying organisms involves education and cultural methods. The public, architects, builders, landscapers, nursery industry and utility companies are simply unaware that what they are doing is leading to serious problems with termites in the future. Long-term management and prevention can only be implemented through a major effort in education. Many cultural methods may be used in construction to reduce the risks from Formosan subterranean termite. However, management of the Formosan subterranean termite is currently not possible without some pesticide unless absolutely no cellulose (wood, paper or their products) is used in construction or furnishing within the structure. One of the most important cultural methods is to change building practices such that ALL wood used in construction is properly preservative treated (borates provide many advantages) to provide protection from many wood-destroying insects and wood-decaying fungi.
The National Association of Home Builders compared the costs in March 2000 of building a one-story, slab-on-grade, 2,457-square-foot, single-family, detached home using untreated wood, CCA-treated wood, light-gauge steel and concrete masonry (Julie Cole, personal communication). Costs were determined for exterior walls, interior walls and the roof system. The additional costs over untreated lumber of each of the other three systems was $1,654 for treated wood, $5,509 for light-gauge steel and $16,092 for concrete masonry. Lumber may be treated with preservatives other than CCA, each resulting in somewhat different cost factors. For example, the costs of treating wood with borates would be approximately 1.5 percent higher than with CCA, resulting in a total incremental cost of $1,679. The cost of the preservatives in pressure treated wood is a small percentage of the cost of the treated wood product (approximately 5 to 7 percent).
The components of IPM at the macro level include education, research and quarantines, while at the micro level they include land preparation, architectural design, building materials and practices, preventative and remedial treatments, inspection and structural maintenance, and treatment of trees. Extension or education of the public is the greatest need to implement IPM of termites. Few people have a good understanding of IPM of termites.
There is a continual need for research. Research provides new tools and tactics and is crucial for the future.
Containment is a very important component of IPM of Formosan subterranean termites and is crucial to slow the spread of the Formosan subterranean termite. It has a great potential to reduce future costs. The Formosan subterranean termite is moved in railroad ties, telephone poles (Henderson 2000), wood from other structures, nursery stock, shipping crates and other cellulose. The alates can be moved on vehicles. The opportunity exists to move this insect all over the world. The Formosan subterranean termite should be treated as a contagious disease. There is a need to get the public to voluntarily stop moving potentially infested material to uninfested areas. This requires a major education effort. The Formosan subterranean termite has been moved into several areas, including Monroe, Louisiana; Austin, Texas; Corpus Christi, Texas; Dallas, Texas; San Diego, California; and Atlanta, Georgia. Infested wood from a boat was thrown in a dump in Shreveport, Louisiana. Presently it is not known if an infestation will begin from this event. The Formosan subterranean termite has been moved to a new location in Louisiana in potted plants.
The first stage of five stages in the life of a structure is land preparation. Do not bury wood because this food put in the ground may increase termite numbers. Slope the grade so that water runs away from the structure.
The design of a structure is the second stage in the life of a structure for managing termites. Every aspect of the structure should be designed to avoid wood-to-soil contact and keep wood dry. Moisture control is needed beneath and around structures. Roofs should not be flat. Drip lines should extend two feet. Design all areas prone to attack so they may be inspected easily. Access panels are needed for all pipes going through the slab. Things passing through the slab are often the first point of access by termites. Snap-on baseboards should be used for easy inspection behind walls. Factors other than low cost and appearance must be considered.
Hollow concrete blocks placed on the soil provide hidden access for termites. The best solution is to not put hollow concrete blocks on the soil. Other, less desirable solutions include filling voids with concrete while preventing shrinkage cracks, using non-shrinking grout and physical barriers. Do not design planter boxes against the house with soil above the grade. Place flashing behind planter boxes attached to the house.
The third stage in the life of a structure is its actual construction. There is a unique opportunity to protect a structure when it is built. Once the structure is built, this opportunity is lost. A very large set of things may be done. The most important of these is to use properly preservative-treated cellulose (wood, paper and their products). Construct slabs to resist cracking. An intact slab is a barrier itself. Consider barriers. Do not provide wood-to-soil contact, a source of moisture or soil above the slab. Build for ease of inspection. Do not leave grade stakes, form boards or slag around the slab. Consider using grade stakes or form boards made from materials other than cellulose. Do not allow stucco or Styrofoam to contact the soil. Consider wood-destroying organisms in everything done.
The fourth stage in the life of a structure is a preventative soil treatment when the structure is built. This stage overlaps the third and fifth stages. The soil should be treated with a termiticide before the slab is poured. The soil around the slab and piers should be treated shortly after construction is complete. Concrete adjoining the slab, hollow piers, brick piers and chain walls touching the ground should be drilled and treated. A set of minimum specifications for treating a structure may be obtained from the Louisiana Department of Agriculture and Forestry.
The fifth stage in the life of a structure, inspection and structural maintenance, is required throughout the lifetime of a structure. Inspect the property on a regular basis. Retreat the soil when needed. Use baits and fumigation if needed. DO NOT break or bridge the soil barrier placed around the structure or provide hidden access for termites. Treat the 4”-wide-by-6” deep treated soil as “holy ground.” Make sure it is undisturbed. DO NOT put soil, rocks, mulch, wood or anything else on it. Keep it dry. DO NOT dig it up. Keep high pH cleansers (bleach) from dropping on it. Plastic may be taped to the structure while the walls are being cleaned. DO NOT allow plants to break the barrier or touch the structure so termites can bridge the barrier. Eliminate hidden access and minimize available wood. DO NOT provide wood-to-soil contact or moisture. Identify the insect causing damage before choosing a remedial treatment. Realize the wood-destroying insect report states whether or not visible evidence of termites was seen at the time the inspection was done. It does NOT state that the structure is not infested. Read the contract carefully and renew contracts.
Several measures for managing termites that could have been done in the previous stages cannot be done in the fifth stage without excessive costs, i. e., untreated wood used in a structure cannot be properly preservative treated and would have to be replaced to achieve the use of properly preservative-treated wood. The failure to incorporate integrated pest management procedures in any stage is most likely to result in termite infestations and additional costs and treatments during the fifth stage. Thus, anything done in any of the stages that increases the risks of termite infestations will become the responsibility of the property owner.
Another component of IPM of Formosan subterranean termites is the treatment of infested trees. Trees may serve as reservoirs for Formosan subterranean termites. The best method for treating infested trees is to foam insecticide in voids and treat the soil around the base of trees. The LSU AgCenter has a video showing how to treat trees (Treating live trees for Formosan termites). Remove stumps.
Landscaping impacts IPM of Formosan subterranean termites. Keep plants a minimum of 3 feet from houses. Do NOT disturb the treated soil. Use termite-resistant materials. Do NOT transport termite-infested wood, plants, mulch or soil. Mulches containing cellulose provide food for termites. All mulches modify temperature and moisture conditions favorably for termites.
Make allowances for imperfection. The reliance on only one or two management tools assumes a degree of perfection in land preparation, architectural design, building materials and practices, preventative and remedial treatments, inspection, structural maintenance and treatment of trees. This perfection is never achieved in practice!
Management tools that perform the same function may be substituted, i. e., graded gravel may be substituted for soil treatment. Management tools that do not perform the same function may not be substituted, i. e., soil treatments or baits are NOT substitutes for properly preservative-treated wood.
Society is very complex, thus as a general rule pest problems can’t be eliminated by simply stopping the activities that encourage the problems (Luckman & Metcalf 1994). However, the failure to stop such activities can result in extremely high costs. Understanding and acceptance of an IPM program are the most important factors in the success of the program. IPM is people-oriented. Success is dependent on influencing people to adopt IPM. Commitment is required, and acceptance without action is useless. Everyone involved with structures is challenged by the Formosan subterranean termite to act.
Humans must decide which costs they choose to pay: direct or lost opportunity costs. They will pay costs from one of these two categories. Direct costs of integrated pest management include training scientists, conducting research, extending information, cultural control, prevention and quarantines. Lost opportunity costs of failing to implement integrated pest management include remedial treatments; repairs; collapse, demolition, and rebuilding of structures; loan defaults; negatively impacted economy; expenditure of tax dollars, and living without specific breakthroughs. Direct costs are usually visible while lost opportunity costs are often difficult to ascertain. The greatest losses of all are those from lost opportunities. In the case of Formosan subterranean termites, everyone who pays taxes has already paid some costs to manage this insect through the expenditure of tax dollars. Which costs do you choose to pay?
Anonymous. 1993. Wood protection guidelines – Protecting wood from decay, fungi and termites. Wood Protection Council National Institute Building Sciences, Washington, DC.
Henderson, G. & C. Dunaway. 1999. Keeping Formosan termites away from underground telephone lines. Louisiana Agriculture 42:5-7.
Henderson, G. 2000. Practical consideration of the Formosan subterranean termite in Louisiana: a 50 year old problem. Proc. 31st Annu. Conf. Int. Res. Group Wood Preservation. Kona, Hawaii, USA. 10330.
Hu, X.P. , D.R. Ring, A.L. Morgan, & D.K. Pollet. 2000. A guide for integrated pest management of termites. LSU AgCenter Publ. 2797. 20 pp.
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