The impact of daily limited prey density levels on some biological characteristics of Phytoseiulus persimilis Athis-Henriot at various temperature and humidity conditions

This study aimed to determine the effects of daily limited prey levels on certain biological characteristics of the predatory mite Phytoseiulus persimilis Athias-Henriot at 25, 30, and 27-35 °C, with relative humidity conditions of 75±5% and 90±5%. In the study, four groups of predatory mites were established by providing varying densities of prey items daily. The first group received one egg, one larva, and one adult male of Tetranychus urticae Koch (Red form) each day; the second group received two eggs, two larvae, and two adult males; the third group received three eggs, three larvae, and three adult males; and the fourth group received four eggs, four larvae, and four adult males daily. All Phytoseiulus persimilis larvae successfully progressed to the protonymph stage without feeding at 25 and 30 °C (75% and 90% RH). However, no egg hatching was observed within the variable temperature range of 27-35 °C under both humidity conditions. The longest mean longevity was recorded at the second prey density level at 25 °C (75% RH), with an average duration of 10 days starting from the protonymph stage. The highest mean egg consumption was observed at 30 °C (75% RH) at the fourth prey level, with a mean of 27.4 eggs. In contrast, the highest consumption of larvae and adult males occurred at 25 °C (90% RH), with means of 26.8 larvae and 29 adult males, respectively, at the fourth prey level. At the first prey level, no oviposition occurred under either temperature or humidity condition. Oviposition of P. persimilis generally increased in tandem with the prey density, with a noticeable rise after the second prey level at 25 °C (75% and 90% RH). The highest oviposition rate, with a total of 1.9 eggs over the entire oviposition period, was observed at 25 °C (90% RH) at the fourth prey level.