Side effects of Zataria multiflora Boiss (Lamiaceae) essential oil on predation and life table parameters of Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae)

Abstract

The predatory mite, Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is one of the most promising candidates for biological control of some economically important mites and insect pests such as spider mites, whiteflies, and thrips. Western Flower Thrips (WFT), Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is a severe economic pest for many crops in the world. In this study the lethal concentrations of Shirazicum thymus: Zataria multiflora  Boiss (Lamiaceae) essential oil was calculated to the adult stage of the WFT. Side effects LC30 and LC50 of the essential oil were assessed on life table parameters and functional response of A. swirskii. Experiments were carried out in growth chambers at 25 ± 1 °C, 60 ± 10% RH, and 16: 8 h (Light: Dark) photoperiod. We utilized the age-stage, two-sex life table method to evaluate the life history features and population growth of A. swirskii on WFT. For assessing the functional response, the first instar of WFT was offered as prey to the adult female of A. swirskii with densities of 2, 4, 8, 16, 32, and 64. The LC50 concentration of the essential oil resulted in lower fecundity (15.05 eggs/female) in comparison with the control (19.8 eggs/female). The application of LC50 and LC30 concentrations also resulted in a significant decrease in net reproductive rate (R0) (8.9, 6.6, and 4.5 eggs per individuals), intrinsic rate of increase (rm) (0.116, 0.093, and 0.077 day -1), finite rate of increase (λ) (1.123, 1.097, and 1.079 day -1), but an increase in mean generation time (T) (18.5, 20.1, and 19.5 days) (for control, LC30, and LC50, applications, respectively). A type II functional response was detected for A. swirskii fed on WFT first instar in all treatments. Adult females of A.swirskii had the highest attack rate (a) (0.11± 0.01 h-1) and shortest handling time (1.61± 0.46h) on control treatment. In conclusion, although Z. multiflora essential oil had potential against F. occidentalis to be applied in integrated pest management programs, the lethal side effects of selected essential oil on the predatory mite, A. swirskii should be considered.