Assessment of Non-Consumptive Predation Risk of (Coleoptera: Coccinellidae) on the Population Growth of (Hemiptera: Aphididae).

How the non-consumptive effects (NCEs) of predators influence the development, survival, fecundity, and population growth of prey has not been well documented, which is the primary consideration for the compatibility of prey with its natural enemies in agricultural ecosystems. We herein employed the age-stage, two-sex life table to examine the NCEs of the predator on the life-history traits and population growth of prey via caged predator (prey co-existing with caged predator) and caged prey (predator co-existing with caged prey) treatments with daily different exposure times (i.e., 0 h (control), 12 h, and 24 h). The results indicated that the predation risk of a caged predator could reduce the first nymphal duration and net reproductive rate () of at 12 h, and the first nymphal duration, preadult duration, and mean generation time () at 24 h. However, the predation risk of the caged prey resulted in the prolongation of the pre-adult development time and total pre-reproductive period (TPRP) as well as lowered the intrinsic rate of increase (), finite rate of increase (𝜆), , life expectancy, and reproductive value of after both 12 h and 24 h. Furthermore, the predation risk of both the caged predator and caged prey could increase the percent of winged morph at 24 h. These findings indicate that could respond to the predation risk of the caged predator by either accelerating the developmental rate or reducing the net reproductive rate, while might reduce their fitness in response to the predation risk of caged prey. Furthermore, might also alter to winged morphs for dispersal under both of the above treatments. The findings obtained have practical ramifications for managing this economically important pest in wheat production with reduced insecticide applications.