A simulation study of boll weevil population dynamics

Abstract

A boll weevil population model is needed for interfacing with available cotton crop models for studying insect pest management decisions and economic thresholds. Most models of boll weevil population dynamics do not allow for biological and/or statistical variation, which increases the error when such models are used on a day-to-day basis. This paper discusses an algorithm that considers important insect population factors in more detail. First, the concept of a developmental unit (DU=time required for 50% of a particular growth stage to develop) is incorporated to account for temperature variations. A normal approximation of developmental times is used, and an error analysis for possible error sources in the numerical procedure. The next step is the development of a simplified relationship for estimating the dynamics of boll weevil feeding and egg-laying. Equations based on temperature and available diet are derived to calculate the fecundity in the field. A sensitivity analysis comparing the model output to observed data shows the feasibility of continuing in this area of research.