Predation on the tomato looper Chrysodeixis chalcites (Esper) (Lep., Noctuidae) by Podisus maculiventris (Say) and Podisus nigrispinus (Dallas) (Het., Pentatomidae)

Abstract

Abstract: Predation by the predatory stinkbugs Podisus maculiventris (Say) and Podisus nigrispinus (Dallas) on the tomato looper Chrysodeixis chalcites (Esper) was studied under laboratory conditions. Nymphs of both Podisus spp. readily attacked eggs, larvae of the second, fourth and sixth instar, and pupae of the prey. However, developmental durations of predator nymphs were generally shorter on fourth‐ and sixth‐instar caterpillars. Adult females also displayed high predation rates against larvae and pupae of C. chalcites, but did not feed on eggs. At 23°C, predation rates of P. maculiventris were generally similar to those of the smaller‐sized P. nigrispinus. Functional responses of adult females of P. maculiventris and P. nigrispinus to the density of fifth‐instar caterpillars of C. chalcites on sweet pepper plants closely approximated Holling's type II response. Estimated values for attack rate and handling time were 0.057/h and 4.71 h for P. maculiventris, and 0.046/h and 4.37 h for P. nigrispinus. In addition, two greenhouse experiments were conducted in which nymphs of P. maculiventris were released against caterpillars of the tomato looper on sweet pepper plants. When fourth‐instar nymphs of the predator were released at a predator: prey ratio of 1:3.3, populations of fourth‐instar caterpillars were reduced by 40% in 48 h, and leaf‐feeding damage after 1 week was reduced by 65%. The potential of these predatory stinkbugs to control outbreaks of noctuid caterpillars in glasshouse crops is discussed.