Impact of microemulsion formulations of selected botanical acaricides on the functional and numerical responses of Amblyseius swirskii Athias-Henriot, 1962 (Acari: Phytoseiidae) feeding on Tetranychus urticae Koch, 1836 (Acari: Tetranychidae)

This study investigated the functional and numerical responses of Amblyseius swirskii Athias-Henriot, 1962 (Acari: Phytoseiidae) when preying on females of Tetranychus urticae Koch, 1836 (Acari: Tetranychidae) under exposure to microemulsion formulations of a terpenoid blend, neem and orange oils compared to a microbial toxin acaricide, milbemectin. Acaricide applications were conducted on eggplant leaves, and their effects were assessed 168 h post-treatment under controlled laboratory conditions (70±5% RH, 27±1°C, and a 16 h light: 8 h dark) during the 2023-2024 experimental period in Bursa Uludag University and Adana Biological Control Research Institute. According to the logistic regression analysis, the control, orange oil, neem oil, and terpenoid blend treatments exhibited a Type II functional response, while milbemectin resulted in a Type III response. The attack rate and handling time of A. swirskii were significantly affected by treatment type. The control group exhibited the highest attack rate (1.03 h⁻¹) and the longest handling time (0.0272 h). Botanical acaricides, orange oil (0.78 h⁻¹), neem oil (0.63 h⁻¹), and the terpenoid blend (0.68 h⁻¹), reduced the attack rate and shortened handling time. Milbemectin had the most adverse effects, resulting in the lowest attack rate (0.29 h⁻¹). These findings suggest that microemulsion formulations of botanical acaricides are less disruptive to A. swirskii than milbemectin and may be better suited for incorporation into integrated pest management (IPM).