Quality Assessment of the Commercially Available PredatorAmblyseius swirskii(Acari: Phytoseiidae)

Abstract

Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is a commercially available predatory mite used to control thrips, whiteflies, and broad mites in horticultural production. The inconsistent quality of mass-produced biocontrol agents is a major concern in augmentative biological control and only a few studies have tested the post-shipment quality of commercial phytoseiids. We evaluated the post-shipment quality of A. swirskii purchased from a commercial provider in the United States. Guidelines for quality control of commercially produced natural enemies, established by the International Organization for Biological Control (IOBC), were followed. Quantity, survival, fecundity, and establishment in ornamenttal peppers (‘Explosive Ember’) were measured. The estimated quantity of A. swirskii motiles (immatures and adults) was quite variable among bran containers (20,968 ± 7,391 mites) but close to the number claimed in the label. Numbers of living A. swirskii females evaluated (n = 30) declined by less than 40% (26 ± 1.25 females) within two days of arrival and declined more than 50% by day eight (15 ± 1.23 females). No significant differences among days sampled were identified for female fecundity; however, fecundity varied considerably among containers. There was no population increase in the ornamental peppers during the two weeks following inoculation with A. swirskii.Accepted for publication 3 September 2016.