The Effect of the Interaction Between Podisus nigrispinus and Brontocoris tabidus (Heteroptera: Pentatomidae) on the Reproductive Biology of the Predators of Agroforestry Pests

To effectively reduce agroforestry pest populations, two or more species of their natural predators, rather than only one, could be released. Podisus nigrispinus (Dallas) and Brontocoris tabidus (Signoret) (Heteroptera: Pentatomidae) are significant pest predators; however, these natural enemies can interact negatively, thereby decreasing the efficacy of biological control. The aim of this research was to study the effect of increasing the density of B. tabidus on the reproduction of P. nigrispinus and vice versa. The number of eggs per egg masses, nymphs, and longevity of P. nigrispinus decreased when the number of B. tabidus females increased. Furthermore, the egg viability was > 75% with one, two, three, and four B. tabidus females; however, with five females, the viability of the P. nigrispinus eggs dropped below 70%. The number of egg masses of P. nigrispinus was similar with increasing density of B. tabidus and, even at low density, P. nigrispinus reduced reproduction of B. tabidus. P. nigrispinus and B. tabidus often occur simultaneously in the field; these predators can coexist without any reproductive damage to any species when both are at low density.