An old predator against a new pest; building a standing army of Podisus maculiventris to control Nezara viridula in sweet pepper

Abstract: The Southern green stink bug Nezara viridula (L.) (Hemiptera: Pentatomidae) has
become a major pest in Dutch greenhouse crops since 2018, particularly in sweet pepper. Since 2022 the egg parasitic wasp Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae) is commercially available in the Netherlands as a biological control agent against N. viridula.
However, parasitism rates are not always 100 % and additional biological control agents against nymphal and adult stages of N. viridula are needed. A predator that does prey upon the juvenile stages of N. viridula is the spined soldier bug Podisus maculiventris (Say) (Hemiptera: Pentatomidae). The spined soldier bug can easily be reared on mealworm larvae (Tenebrio molitor) (L.) (Coleoptera: Tenebrionidae). Therefore, in this study we evaluated if it is possible to establish a population of P. maculiventris in sweet pepper by providing T. molitor as an alternative prey. Our greenhouse trials showed that that a weekly provision of mealworm larvae in sweet pepper successfully established a “standing army” of P. maculiventris. This standing army of P. maculiventris resulted in an excellent control of N. viridula, whereas in treatments without alternative prey the population of P. maculiventris declined.