Effectiveness of the predatory mite Neoseiulus cucumeris on two-spotted spider mite and western flower thrips: A quantitative assessment

Abstract

The present study describes the feeding effects of Neoseiulus cucumeris Athias-Henriot (Acari: Phytoseiidae) on western flower thrips (WFT), Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) and two-spotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae). In addition, daily and total predation capacity, preference, and prey switching potential of this predator were studied on both pest species. WFT had a boosting effect on the biological parameters of N. cucumeris, primarily resulting in shorter developmental time, higher fecundity, and higher population growth potential than TSSM. Although immatures and males of N. cucumeris consumed significantly more TSSM than WFT, there was no significant difference in net predation rate, stable and finite predation rates of the predator between two prey species. We found an average of 10.58 and 7.93 TSSM and WFT are required to produce a single predator egg, respectively. WFT is preferred over TSSM by the predator. Negative switching behaviour was seen in N. cucumeris as it switched from the abundant prey to the rare prey. Both prey species were suitable for N. cucumeris, being able to develop successfully on them. The predator performed optimally on WFT compared with TSSM owing to its enhanced biological parameters as well as its preference, indicating that thrips are a more relevant resource than spider mites.

Keywords: Frankliniella occidentalis; Tetranychus urticae; biological control; negative switching; predation rate.