Acarological Society of Iran Persian Journal of Acarology 2251-8169 3 1 2026 02 01 Spatial and temporal distribution of Eotetranychus frosti and Cenopalpus irani and their predator Typhlodromus bagdasarjani in an unsprayed apple orchard at Khorramabad, Western Iran 51 61 241565 10.22073/pja.v3i1.10130 EN Shahriar Jafari Department of Plant Protection, Faculty of Agriculture, Lorestan University, P.O. Box: 465, Khorramabad, Iran; Mojtaba Rahmati Department of Entomology and Plant Pathology, College of Aboureihan, University of Tehran, Tehran, Iran: Fereshteh Bahirae Department of Plant Protection, Faculty of Agriculture, Lorestan University, P.O.Box: 465, Khorramabad, Iran; Journal Article The spatial and temporal distribution of <em>Eotetranychus frosti</em> (McGregor), <em>Cenopalpus irani</em> Dosse, and their dominant predator <em>Typhlodromus bagdasarjani </em>Wainstein & Arutunjan were studied in an unsprayed apple orchard in Chaghalvandi region (Lorestan Province, Iran) during 2012. The population densities of these phytophagous mites and their predator were monitored from 3^th May to 4^th November 2012. For this purpose, samplings were done 17 times and at each of them, mite counts were made on 60 leaves (i.e. sampling unit). The spatial distribution pattern of <em>E. frosti</em>, <em>C. irani</em> and T. <em>bagdasarjani</em> was determined by using Taylor’s power law method. Calculated RV (relative variation) and reliable sample size for the 25% variation from preliminary sampling for <em>E. frosti</em> were 16.22% and 53.86, respectively. The results demonstrated that population fluctuations of <em>E. frosti</em> and <em>T. bagdasarjani</em> passed through two peaks whereas <em>C. irani </em>had only one peak. The highest densities were observed on 23^th August (28.68 per leaf), 11^th September (28.88 per leaf) and 11^th August (1.18 per leaf) for <em>E. frosti</em>, <em>C. irani </em>and<em> T. bagdasarjani</em>, respectively. The slopes of Taylor's power law were significantly greater than 1 indicating aggregated spatial distributions in the <em>E. frosti </em>and<em> C. irani</em>, but <em>T. bagdasarjani</em> had b= 1, indicating random distribution. Our findings disclosed a positive correlation between population fluctuations of the two phytophagous mites and the predator, indicating a density-dependent reaction of predator to prey densities. The relationship between meteorological parameters and the three mite populations studied showed that the effect of temperature was insignificant, whereas the effect of relative humidity was significantly negative. https://www.persianacarology.org/article_241565_59f01d0a6449a13fcc89f67cedd1be7d.pdf