Functional and numerical responses, mutual interference, and resource switching of Amblyseius swirskii on two-spotted spider mite

Authors: FATHIPOUR, YAGHOUB - TARBIAT MODARES UNIVERSITY; MALEKNIA, BAHADOR - TARBIAT MODARES UNIVERSITY; BAGHERI, ABDOOLNABI - TARBIAT MODARES UNIVERSITY; SOUFBAF, MAHMOUD - TARBIAT MODARES UNIVERSITY; Reddy, Gadi V.P.

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2020
Publication Date: 3/31/2020
Citation: Fathipour, Y., Maleknia, B., Bagheri, A., Soufbaf, M., Reddy, G.V. 2020. Functional and numerical responses, mutual interference, and resource switching of Amblyseius swirskii on two-spotted spider mite. Biological Control. 146:104266. https://doi.org/10.1016/j.biocontrol.2020.104266.
DOI: https://doi.org/10.1016/j.biocontrol.2020.104266

Interpretive Summary: The two-spotted spider mite (TSSM) is the most polyphagous species of the family Tetranychidae, causing economic losses on many important greenhouse and field crops, including cucumber. The main purpose of this study was to determine several foraging behavior parameters of spider mite as a biological control agent of TSSM. In this study, since the success of a predator in a biological control program depends on its behavior under various prey densities and in the presence of other conspecific competitors, we determined the functional response and mutual interference of spider mite under different densities of prey and conspecific predators. The data obtained in this study can be used to predict predatory mite behavior and its efficacy in control of two-spotted spider mite populations. This study revealed the switching behavior of predator switched from one life stage of TSSM when it became rare to another stage that is more abundant. By these results, we can say that the interference coefficient for predatory mite in the presence of pollen was less than that in the absence of pollen. Together, the results of this study revealed high performance of predatory mite on TSSM and the importance of pollen in its efficiency.

Technical Abstract: The predatory mite Amblyseius swirskii Athias-Henriot (Acari, Mesostigmata: Phytoseiidae) has been used to control greenhouse pests including thrips, whiteflies and the two-spotted spider mite (TSSM), Tetranychus urticae Koch (Acari, Trombidiformes: Tetranychidae). This study evaluated A. swirskii’s potential to control TSSM by determining the functional response, numerical response, mutual interference, and prey switching behavior of the predator in the presence or absence of pollen under laboratory conditions. Type II and III functional responses were determined for A. swirskii fed on TSSM in the absence or presence of pollen, respectively. The highest predation rate and searching efficiency (a) was observed on eggs of TSSM compared with nymphs in all experiments. The numerical response of the predator showed a rapid and significant increase in oviposition with increasing TSSM density (both eggs and nymphs) but the rate gradually declined at higher densities of TSSM in both the presence and absence of pollen. The efficiency of conversion of ingested food (ECI) was highest at low prey density, and decreased at higher prey densities. The per capita searching efficiency of the predator also decreased significantly with increasing predator density. The interference coefficient for A. swirskii in the presence of pollen was less than that in the absence of pollen. Switching behavior was observed in A. swirskii in which the predator switched from one life stage of TSSM when it became rare to another, more abundant stage. The results of this study revealed high performance of A. swirskii on TSSM and the importance of pollen in its efficiency.