Acarological Society of Iran Persian Journal of Acarology 2251-8169 15 2 2026 04 01 Effect of temperature on the biological parameters of the predatory mite, Phytoseiulus persimilis (Acari: Phytoseiidae) 1 9 242092 10.22073/pja.150204 EN Seyed Mohammad-Mahdi Sarvi Department of Plant Protection, College of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran Malihe Latifi Department of Plant Protection, College of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran Seyyed Rasoul Sahhafi Department of Genetics and Plant Production, College of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran Journal Article 2025 09 14 The two-spotted spider mite, <em>Tetranychus urticae</em> Koch (Acari: Tetranychidae), is a major agricultural pest, and the predatory mite <em>Phytoseiulus persimilis</em> Athias-Henriot is one of its most effective natural enemies. Since temperature strongly influences predator biology, in the present study, the effects of five constant temperatures (21, 23, 25, 27, and 29 °C) on the development, survival, and reproduction of <em>P. persimilis</em> using age-stage and two-sex life table analysis were evaluated. Developmental time decreased with increasing temperature, while reproductive onset occurred earlier at warmer conditions. Maximum fecundity, net reproductive rate (<em>R</em>0 = 14.62), and intrinsic rate of increase (<em>r </em>= 0.35) were recorded at 25–27 °C, indicating an optimal range for population growth. However, adult longevity and reproductive performance sharply declined at 29°C, suggesting heat stress limitations. These results confirmed that <em>P. persimilis</em> exhibits peak biological performance at moderate temperatures (24–27°C), reinforcing its suitability as a biocontrol agent under controlled environments but highlighting reduced efficiency under extreme heat. The findings provided practical insights for optimizing mass rearing and field release strategies within integrated pest management programs. https://www.persianacarology.org/article_242092_483e11b323ba61276926679ff49f2ee7.pdf