Early establishment of the phytoseiid mite Amblyseius swirskii (Acari: Phytoseiidae) on pepper seedlings in a Predator-in-First approach

The establishment of biocontrol agents is critical for success of biological control strategies. Predator-in-First (PIF) is a prophylactic control strategy that aims to establish predators before the appearance of pests in an agro-ecosystem. PIF uses the ability of generalist phytoseiid mites to survive, develop and reproduce on pollen and thus establish in the absence of prey. The early establishment of populations of natural enemies helps control the pests at their incipient stage of infestation. The current study was undertaken to screen pepper cultivars for their ability to support populations of the predatory mite Amblyseius swirskii Athias–Henriot in the absence of prey. Twenty-nine pepper cultivars (11 hot and 18 sweet) were tested through a series of experiments, and four cultivars (7141, 992-7141, FPP7039 and FPP9048) were found to sustain A. swirskii populations throughout the study period. The initial application of pollen was important for establishment and maintenance of the predatory mites within the greenhouse system. Among the three screening experiments, high densities of mites were obtained in the experiment where 20 mites were released per plant, even reaching densities of >100 mites/plant. Recovery of predatory mites was significantly higher (ca. 2–3 fold) on the four pepper cultivars when predatory mites were mass released using an indirect method (banker plants) than when they were released directly on the seedlings, suggesting an advantage of passive continuous release. Future work will evaluate the selected pepper cultivars with the PIF strategy under greenhouse and field production conditions.