Functional and numerical responses of the predator Amblyseius swirskii to its prey Tetranychus turkestani in the laboratory

Atefeh Rahmani Piyani,Eric W Riddick,Parviz Shishehbor,Farhan Kocheili

doi:10.24349/r82w-ylj1

Atefeh Rahmani Piyani, Eric W Riddick + Show 2 more

Open Access

https://doi.org/10.24349/r82w-ylj1

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Abstract

The tetranychid Tetranychus turkestani Ugarov and Nikolskii is a serious pest of many important crops around the world. Management of T. turkestani by augmentative biological control using predators such as the phytoseiid Amblyseius swirskii (Athias-Henriot) is envisioned as an environmentally safe alternative to acaricides. Foundational knowledge on T. turkestani – A. swirskii interactions in the laboratory are necessary to predict the outcome of A. swirskii augmentative releases in the field. In this study, the functional and numerical responses of adult A. swirskii females feeding on immature stages of T. turkestani were determined in the laboratory. Prey densities were 2, 4, 8, 16, 32, 64, or 128 individuals per Petri dish arena. The functional response of A. swirskii to prey showed a Holling's type II response. The attack rate and handling time estimates from the random predator equation were 0.1148/h and 0.3146 h, respectively, indicating that A. swirskii consumed 76.28 individuals per day at the maximum level. The number of eggs laid by the predator, i.e., the numerical response, increased as host density increased up to a maximum of 33.10 eggs per female; then oviposition rate leveled-off. This study suggests that A. swirskii is a suitable candidate for augmentative biological control of T. turkestani but follow-up experiments in greenhouses or open fields are necessary.

Highlights

Tetranychus turkestani Ugarov & Nikolskii (Acari: Tetranychidae) is an important pest of different field and glasshouse crops in the southwestern region of Iran (Mossadegh and Kocheili 2003), Russia (Popov 1981), USA (Jeppson et al 1975), China (Li et al 2014), India and some European countries (Zhang 2003)
The functional response displayed by A. swirskii was well-defined by the Roger’s model
The functional response curve reached a plateau at approximately 64 prey individuals during 24 h, suggesting a type II functional response where predation rate decreased as prey density increased

Summary

Introduction

Tetranychus turkestani Ugarov & Nikolskii (Acari: Tetranychidae) is an important pest of different field and glasshouse crops in the southwestern region of Iran (Mossadegh and Kocheili 2003), Russia (Popov 1981), USA (Jeppson et al 1975), China (Li et al 2014), India and some European countries (Zhang 2003). The hosts of T. turkestani are species of Solanaceae, Cucurbitaceae and Fabaceae in Khuzestan province, southwestern of Iran (Mossadegh and Kocheili 2003; Sohrabi and Shishehbor 2008). Tetranychus turkestani is often found on field bindweed (Convolvulus arvensis L.), which may serve as a reservoir, and on several other weed species along road margins. This mite has several generations during the growing season, tolerates high temperatures and low humidity and has a short generation time of approximately 10 - 12 days (Sohrabi and Shishehbor 2008). Tetranychus turkestani initially feed on the lower leaf surface but can cover an entire plant as

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