Coupling age-stage life tables with predation trajectories to inform release timing of Chrysoperla nipponensis (Neuroptera: Chrysopidae) and Propylea japonica (Coleoptera: Coccinellidae) against the corn leaf aphid, Rhopalosiphum maidis (Hemiptera: Aphididae).

Successful augmentative biological control depends on releasing predators before prey populations enter their period of fastest increase, yet release schedules rarely integrate predator feeding capacity with prey demography. We combined an age-stage, two-sex life table of the corn leaf aphid, Rhopalosiphum maidis (Fitch), with age-specific predation trajectories of two generalist predators, Chrysoperla nipponensis (Okamoto) and Propylea japonica (Thunberg), measured under excess-prey laboratory conditions. To compare the release forms evaluated here, we derived an operational suppression ratio linking predator lifetime consumption to prey net reproduction and used this framework to align predator consumption with aphid effective fecundity on a common time axis. The analyses showed clear differences in both suppression potential and timing basis between the two predators. Lacewing larvae expressed their strongest contribution over a relatively narrow interval associated with late larval stages, whereas adult P. japonica provided a broader feeding window beginning soon after adult emergence. This coupling framework identified practical release windows for lacewing eggs, late-instar lacewing larvae, and adult ladybird beetles relative to the expected aphid fecundity peak. Our results provide a laboratory-based decision framework for improving release timing in augmentative biological control programs targeting aphids in corn and offer a basis for future translation of these schedules into degree-day-based pest management guidance.