An energy-flow multitrophic-level model incorporating acquisition (functional response) and assimilation (metabolic pool model) functions and stochastic development is proposed and put into historical perspective. The model is general for each trophic level and for all subcomponents. Prey demand drives the functional response model, while food supply–demand determines all intrinsic rates in the model. The model is used to explore the theoretical properties of a multitrophic system comprising alfalfa, blue aphids, pea aphids, a host-specific parasitoid, and two predators (lady beetles, green lacewings). The model shows:
(1) the importance of the resource base on higher trophic level dynamics and vice versa
(2) the stability properties of different combinations of species
(3) the role of parasitoids and predators in population regulation in this system
(4) how food acquisition and respiration as functions of temperature and per capita resource interact to determine the rate of population growth
(5) that extreme caution must be used in extrapolating theoretical results to field situations.