ABSTRACT
This chapter discusses a discrete-choice economic threshold model is developed for control of rangeland grasshoppers. The economic threshold concept has been widely accepted among entomologists as the basis for making rational pest management decisions. Economists have developed complex mathematical models to consider optimal pest management strategies. For rangeland pests such as grasshoppers, the discrete-choice threshold model is adequate. The rate at which a grasshopper infestation destroys forage is a variable function of grasshopper population composition, stage of development, and rate of survival over time. Entomologists have tried, without much success, to predict grasshopper outbreaks. Several factors, including available food supply and environmental influences, have been identified as important determinants of grasshopper populations. The long-term effectiveness of grasshopper control programs is uncertain. The efficacy of insecticides applied to control rangeland grasshoppers will vary, depending on the temperature and amount of precipitation on the day of application, terrain, uniformity of application, and type of vegetation.
