Contributors: C.S. Apperson, Extension Entomology Specialist; J.R. Baker, Extension Entomology Specialist; L. Garcia, Plant Protection Section, NC Dept. of Agriculture; M.G. Waldvogel, Extension Entomology Specialist.


Application of IPM Principles To Structural Pests

For decades, Integrated Pest Management (IPM) has been a driving force in American crop production. Development and adoption of IPM was stimulated by recognition of the fact that, in most situations, the total eradication of a pest is neither economically feasible nor environmentally sound. A more reasonable alternative is to manage the pest and prevent the population from reaching levels that create unacceptable economic losses. At the same time, there was a growing realization that reliance on pesticides as the sole method of controlling pests increased the potential for adverse environmental consequences. The time has come to adapt the IPM approach to preventing or correcting pest problems in structural situations. The "commodity" to be protected from pest infestation, in this case, is the building. Although structural pests are different from those found in agricultural settings, the concepts behind an IPM approach still apply.

What Is an IPM Approach?

Traditional pest control in the structural setting relies almost exclusively on preventive, calendar-based (monthly or quarterly), pesticide applications, without considering whether or not a pest problem actually exists. While a preventive chemical approach could be considered proactive, pesticide applications without information about actual pest problems is of questionable cost effectiveness. On the other hand, applying pesticides only after pests have reached intolerable levels, is equally unacceptable.

IPM alternates proactive and reactive phases. The proactive phase determines whether there is actually a pest problem. Just as in agricultural situations, where fields are scouted for the presence of pests, IPM in an structural situation begins with site inspection. Phase 1 of an IPM program includes identifying the pest(s) and learning something about their biology and behavior: what is their life cycle? what do they eat? where do they tend to be found?

This information is then applied to carry out Phase 2 which consists of determining the size and extent of any infestation found and determining possible causes of the problem.

Except for the occasional "nuisance pests" (such as millipedes or fungus gnats), pests commonly found in and around a structure ("peridomestic" pests) are attracted to the area by three factors: food, water, and harborage (a protected place in which to live and proliferate). Depending upon the pest, visual inspections and/or monitoring devices, such as sticky boards, can be used to help assess pest population density.

With information about the pest and its distribution in the facility, Phase 3, selection and implementation of the best management tactics, can be carried out. The selection of management strategy for any particular situation takes into account not only their effectiveness in getting the job done, but also their possible environmental consequences.

The goal of IPM is to achieve satisfactory, economical pest control with minimal or negligible environmental consequences. Control must be considered in terms of both short-term and long term strategies or objectives. The short-term objective is most often the immediate removal of the current pest infestation. The long-term focuses on preventing a recurrence of the problem. Unlike traditional pest control, which relied almost exclusively on pesticides, IPM integrates all possible methods of pest control: mechanical, chemical and (sometimes) biological. These include:

  1. Limiting the pest's access to food, water and harborage sites:
  2. Use of mechanical devices (such as traps) to remove pests.

  3. Pesticide applications that have minimal risks associated with their use. Factors for consideration here include selecting:

The Limited Relevance of Thresholds

In agriculture, the pest population levels at which some control measures are enacted are referred to as action or economic thresholds. These thresholds are based on the value of the commodity (anticipated market value); the amount of damage that the particular pest populations could cause and the economic consequences of that damage; the cost associated with implementing particular control measures.

In the urban or structural setting, there are limits to complete adaptation of the IPM approach, particularly with regard to these thresholds. Although, costs of potential control measures can be calculated, it is difficult, if not impossible, to assign a realistic value to the "commodity" or to the economic consequences of infestation. Notable exceptions would be the wood-destroying pests, such as termites, where cost of repair can be more easily calculated. Likewise, contamination of food by cockroaches, rodents or ants renders it unmarketable or unusable, providing a somewhat more concrete value to the actual losses. However, for most of common peridomestic pests, the value of the "commodity" and the losses caused by pest activity may be of a more aesthetic or perceived nature.

For example, while the presence of cockroaches in some areas of a facility may be tolerated, their presence in the food preparation or consumption areas of that same facility would be unacceptable to county sanitation inspectors and to customers. In such a situation, the threshold is essentially set to zero. Attempts to establish workable "action thresholds", i.e., the pest level that triggers pest control procedures have met with limited success because of extenuating circumstances, such as state or federal regulations governing the facility, or simply because of the diversity of opinions on the part of facility occupants as to what constitutes "a problem".

Nevertheless, The fundamental components of IPM: inspection, monitoring, and long term preventive strategies can and should be readily implemented in structural settings.

Structural Pest Control and the Law Red Imported Fire Ant Centipedes and Millipedes
Pillbugs Earwigs Mosquitoes
Spiders Carpenter Bees Human Lice
Fleas Ticks

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Last Modified: 07/10/96