Predation rate of Amblyseius swirskii (Acari: Phytoseiidae) on western flower thrips

Amblyseius swirskii Athias-Henriot is one of the major biological control agents used in biological control programs for a variety of pests. However, before using a natural enemy in a biocontrol program, it is essential to know its effectiveness. In this study, the age-stage, two-sex predation rate of A. swirskii was determined on Frankliniella occidentalis (Pergande) under laboratory conditions at 25 ± 1 °C, relative humidity of 60 ± 5%, and a 16: 8 h (L: D) photoperiod. The means and standard errors of the predation parameters were estimated using the bootstrap resampling procedure. According to the obtained results, the age-stage specific predation rate (cxj) of female adulte of the predator was higher than the other stages. Their predation rates were zero for the non-predatory stages (e.g., egg and larva). The value of net predation rate (C0), the mean number of prey consumed by an average individual predator during its entire life span, on F. occidentalis was 159.25 preys/predator. In addition, the value of finite predation rate (ω) and stable predation rate (Ψ) were 2.635 preys/predator/day and 2.208 preys/predator, respectively. The value of transformation rate (Qp), the mean number of prey that a predator needs to consume to produce an offspring, was 8.39 prey. Consequently, the obtained results in this study could provide important information in the design of a comprehensive program for controlling F. occidentalis by predatory mite, A. swirskii on crops.