Evaluation of four release methods for Amblyseius swirskii on bell pepper commercial production

The predatory mite Amblyseius swirskii is used to control pests on vegetables. The release method impacts predation rate and foraging behavior. The traditional method is manual sprinkling, but there are other release methods such as mechanical distribution using blower machines, and the slow-release methods using sachets or small bags, and small boxes containing a blend of factitious prey. We hypothesized that there might be an A. swirskii release technique other than the manual that could be more efficient and affordable in pepper crops. The specific objectives were (a) to determine the most effective method to release A. swirskii, (b) examine the population dynamics of A. swirskii, and (c) conduct an economic analysis to choose the most advantageous release technique. The experiment was conducted on a commercial pepper in Honduras. There were four replicates in the experimental plot and four treatments —manual release as industry control, blower, sachet, and box— in a randomized complete block design. The number of predator eggs did not significantly vary among treatments (ANOVA: F=2.02, df=3, P=0.1101), although the sachet had the larger number of eggs during the first week. A. swirskii motile population was the lowest under the blower method. Regarding the release cost, blower has the biggest investment cost of 1277 USD/hectare, but this equipment is only bought once. The preliminary data analysis shows the blower release method could be a financially viable alternative to manual release in large crop extensions and it is a way to reduce times and labor costs.