A model is described for stimulation of the population dynamics ofHeliothisspp. The salient features of the model include: (1) developmental means and variances about these means nonlinearly dependent on temperature; (2) separation of the general adult pool through adult attraction to spatially and temporally variant host-plant characteristics; and (3) cannabalism as a function of larval density, age-class structure within larvae, available feeding sites, and larval spatial distribution.Results of an initial simulation effort are also presented.