A model simulating mating behaviour of Spodoptera littoralis.
A computer model was developed simulating the mating behaviour and population increase of adults of Spodoptera littoralis (Boisd.) in an isolated group of lucerne or potato fields surrounded by bare ground. Whenever possible the input was based on the results of field work in Cyprus where a synthetic sex attractant was also tested as a preliminary to its possible use for control. The effect of varying different parameters, including sex ratio, immigration and emigration rates and the rate of emergence from the overwintering population was examined before control measures were simulated in the model. The results suggest that the size of the overwintering population and the time it takes to emerge are critical factors. With a very small overwintering population, the best strategy to ensure establishment on a site is for emigration to be restricted at the beginning of the season and females to outnumber males. Trapping and confusion techniques were tested in the model using the sex attractant. The results suggest that neither technique is likely to provide reliable crop protection unless applied intensively from the start of the season.