Compatibility Conflict: Is the Use of Biological Control Agents with Pesiticides a Viable Management Strategy?

Biological control or the use of natural enemies is an alternative pest management strategy for dealing with arthropods. However, natural enemies may not always provide adequate control of plant-feeding insects and mites in greenhouses. As a result, research has assessed the concept of using natural enemies in conjunction with pesticides and the potential compatibility when both pest management strategies are implemented together. There are a variety of factors that influence the ability of using natural enemies with pesticides, these include whether the natural enemy is a parasitoid or predator, natural enemy species, life stage sensitivity, rate of application, timing of application, and mode of action of a particular insecticide or miticide. Pesticides may impact natural enemies by affecting longevity (survival), host acceptance, sex ratio, reproduction (fecundity), foraging behavior, percent emergence, and development time. In our studies, we have found a number of pesticides to be compatible with the natural enemies of the citrus mealybug, Planococcus citri and fungus gnats, Bradysia spp. For example, we have demonstrated that foliar and drench applications of the insecticides novaluron and pyriproxyfen, and the fungicides fosetyl-Al and mefenoxam to be compatible with the predatory mite, Stratiolaelaps scimitus. We have also shown that the insecticides azadirachtin and pyriproxyfen are compatible with the citrus mealybug parasitoid, Leptomastix dactylopii. Additionally, the insecticides buprofezin, pyriproxyfen, and flonicamid were not harmful to the adult stage of the mealybug destroyer, Cryptolaemus montrouzieri. Despite the emphasis on evaluating the compatibility of natural enemies with pesticides, it is important to assess if this is a viable and acceptable pest management strategy in greenhouses.