Developmental response of the beneficial predator Podisus maculiventris to change in dietary ascorbic acid concentration

We report here the effects of a range of ascorbic acid concentrations (0.07, 0.3, 3.0, and 30.0 g l−1) in artificial diets on growth rates, adult weights, fecundity, and survival over two generations of the predatory stink bug, Podisus maculiventris (Say) (Heteroptera: Pentatomidae). Overall, a dietary level of 3.0 g l−1 gave the shortest developmental times over two generations. The likelihood of egg hatch at one ascorbic acid concentration compared to another concentration suggested that egg hatch increased as the concentration of ascorbic acid increased from 0.07 to 3.0 g l−1 and then declined from 3.0 to 30.0 g l−1. The combination of the maximum egg oviposition at 0.3 and 3.0 g l−1, egg hatch at 3.0 g l−1, and survival at 0.07 and 0.3 g l−1 suggests an overall superior performance at a concentration between 0.3 and 3.0 g l−1. Depletion of ascorbic acid below 3.0 g l−1 or addition of ascorbic acid above 3.0 g l−1 lowered the likelihood of egg hatch, which became more pronounced in the second generation. This is consistent with previously published information for phytophagous insects.