Moderate parental starvation preserves progeny population fitness and increases predation in Picromerus lewisi: transgenerational evidence from age-stage, two-sex life tables

Picromerus lewisi Scott (Hemiptera: Pentatomidae) is a dominant predatory natural enemy in agroforestry pest management. Although P. lewisi frequently experiences food deprivation during biological control programs, the effects of parental starvation followed by re-feeding on parental reproductive fitness, F 1 offspring performance, and predation-related traits remain unclear. We evaluated the effects of 0-, 10-, and 20-d parental starvation followed by re-feeding on P. lewisi using age-stage, two-sex life table analysis, with Ephestia elutella (Hübner) (Lepidoptera: Pyralidae) as prey. Twenty-day starvation markedly reduced fecundity (70.62 and 11.14 eggs in the parental and F 1 generations, respectively) and oviposition duration (2.33 and 1.67 days, respectively) in both generations. This treatment also suppressed F 1 population growth, with the net reproductive rate ( R 0 ), intrinsic rate of increase ( r ), and finite rate of increase ( λ ) decreasing to 3.86 individuals, 0.0247 d -1 , and 1.0250 d -1 , respectively. In the 120-d simulation, the population reached only 111 individuals, whereas the transformation rate ( Q P = net predation rate [ C 0 ]/ R 0 ) increased to 12.67. By contrast, 10-d parental starvation increased F 1 survival (46.00%) and population growth, producing a simulated population of 1,207 individuals on day 120 while maintaining a low transformation rate of 2.61. These findings suggest that short-term (10-d) parental starvation followed by re-feeding can improve the survival and predation performance of P. lewisi without an evident fitness cost, providing a theoretical and practical basis for mass rearing and field deployment of this predator in biological control.