A mathematical model of the population dynamics of the lesser cornstalk borer, Elasmopalpus lignosellus

Abstract

A simulation model was developed for the population dynamics of the lesser cornstalk borer, Elasmopalpus lignosellus (Zeller) (Leipdoptera: Pyralidae), in sandy loam soil. The model includes: temperature-dependent growth of E. lignosellus eggs, larvae, pupae, and adult age; temperature and age-dependent oviposition; and soil moisture-dependent mortality of eggs and larvae. Egg, larval, pupal and adult survivorship are also incorporated. Analyses were conducted to determine the model's sensitivity to changes in selected parameters. Sensitivity analysis simulations without rainfall indicated the model was most sensitive to the interaction of the proportion of adult females in each of three age classes by the oviposition and developmental thresholds, indicating adult biology must be very accurately estimated for model predictions to be accurate. One main effect (degree-day requirements for E. lignosellus eggs, larvae, pupae, preoviposition, and longevity) ranked in the four most influential effects. Two main effects were highly ranked in the sensitivity analyses with simulated rainfall: (a) parameters in the sixth-order polynomial for calculation of the oviposition rate; and (b) parameters in the two-independent-variable polynomial used to calculate the daily maximum soil temperature for degree-day computation. Thus, adult biology and soil temperature parameters must be accurately estimated for the model to function under rainy conditions. Both of these effects ranked ⩽ 3rd in the analyses with rainfall.