A conceptual model was developed based on the two basic spatial elements of area-wide integrated pest management (AW-IPM), a core area and a buffer zone, to determine the minimum size of the protected area for the program to be technically feasible and economically justifiable. The model consisted of a biological part (insect dispersal) and an economic part. The biological part used random walks and diffusion equations to describe insect dispersal and to determine the minimum width of the buffer zone required to protect the core area from immigration of pests from outside. In the economic part, the size of the core area was calculated to determine the point at which the revenues from the core area equal the control costs. This model will need to be calibrated and validated for each species and geographic location. Tsetse flies and the Mediterranean fruit fly are used as case studies to illustrate the model. 1. Introduction Classical integrated pest management (IPM), which aims at managing pests by the integration of biological, cultural, physical, and chemical tools in a way that minimizes economic, health, and environmental risks [1], has remained a dominant paradigm of pest control for the last 50 years. The different control tactics can be integrated on a field-by-field basis or by using an area-wide approach [2]. Area-wide integrated pest management (AW-IPM) is the integrated use of various control tactics against an entire pest population within a delimited geographical area to achieve economic control [3]. The importance of this approach of “total pest population management” has significantly increased for many pests in the past decades, and it is now generally accepted that AW-IPM leads, in many cases, to more sustainable pest control especially for mobile insects [2]. A powerful AW control tactic is the sterile insect technique (SIT), which over the past decades has become accepted as an efficient and cost-effective part of AW-IPM programs against a selected number of insect pests of veterinary, human health, and agricultural importance [4]. A recurrent concern for pest managers is the minimum size of the target area that needs to be considered for an AW-IPM program to be technically viable and economically justifiable. Due to the lack of adequate practical experience and the absence of models, decisions were sometimes based on educated guesses rather than on sound, scientific principles. Therefore, a conceptual mathematical model was developed that can assist with estimating the minimum area that needs to be considered to successfully apply a
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