Simulation Modelling as a Decision Support in Developing a Sterile Insect-Inherited Sterility Release Strategy for Eldana saccharina (Lepidoptera: Pyralidae)

• Published in: The Florida entomologist Vol. 99; no. sp1; pp. 13 - 22
• Main Authors: Potgieter, Linke, Vuuren, Jan H. Van, Conlong, Des E
• Format: Journal Article
• Language: English
• Published: Lutz Florida Entomological Society 01-06-2016
• Subjects: African sugar cane borer; barrenador de caña de azúcar de África; configuraciones de campo de caña de azúcar; control de plagas; dinámica de la caña de azúcar; dinámica de la población de plagas; dinámica del medio ambiente y la economía; Ecosystems; Eldana saccharina; environmental dynamics and economics; esterilidad heredada; Growth models; Influence; inherited sterility; Insect sterilization; INTRODUCTION AND THEORETICAL/PRACTICAL FRAMEWORK; Lepidoptera; Methods; Pest control; pest population dynamics; Population growth; Pyralidae; Simulation; Sugarcane; sugarcane dynamics; sugarcane field configurations; Wildlife management; South Africa, KwaZulu-Natal; ASW, USA, Florida; Africa
• ISSN: 0015-4040; 1938-5102
• DOI: 10.1653/024.099.sp103

A user-friendly simulation tool for determining the impact of the sterile insect technique/inherited sterility technique (SIT/IS) on populations of the African sugarcane stalk borer, Eldana saccharina Walker (Lepidoptera: Pyralidae) is described in this paper. The simulation tool is based on a spatio-temporal model. The design of the simulation tool is such that it is applicable for use in a number of pest/crop and pest control scenarios. It uses 4 interacting subsystems (pest species population dynamics, crop dynamics, environmental dynamics and economics) within a specified spatial domain. Furthermore, the spatial domain describes the layout of the agricultural crop (position, size, shape, crop age and variety of the different fields contained within the crop area). The pest species population subsystem describes E. saccharina population dynamics (but is designed to also include population dynamics of other pest species) under the influence of the IS technique. The E. saccharina module developed utilizes mean-field and spatio-temporal models, and includes dynamics of all E. saccharina life stages under the influence of the control measure. Only temperature and damage caused by E. saccharina are currently included as variables in the sugarcane dynamics subsystem. This subsystem estimates stalk length as a function of time and temperature, and sucrose percentage as a function of damage caused by E. saccharina boring. Interaction between E. saccharina population growth and sugarcane growth is described by a decreasing s-shaped density-dependent mortality function—the older the cane, the higher the carrying capacity (more food resources) and corresponding infestation and damage levels. The only environmental factor considered as an independent variable in the environmental dynamics subsystem is temperature. Possible extensions to this subsystem are discussed. The economics subsystem developed includes the estimation of the recoverable value, percentage, expected revenue and the cost of control. No other farm expenditures are taken into account. As such only profit or loss expected from applying the IS technique is estimated. The profit or loss is defined as the increase in revenue expected less the cost of applying a pest control measure. An example of using the simulation tool is presented in the context of a real field scenario of a simulated SIT/IS program against E. saccharina at a pilot site near the Eston area of KwaZulu-Natal, South Africa.