Impact of hunger levels on the prey consumption of Neoseiulus californicus and its efficacy in controlling Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae)

The study evaluated the impact of hunger levels on the prey consumption of Neoseiulus californicus (McGregor) sensu Athias-Henriot (Mesostigmata: Phytoseiidae) and its effectiveness in controlling Tetranychus urticae Koch (Trombidiformes: Tetranychidae) on bean plants. The effect of the hunger level on the consumption capacity of N. californicus was investigated using eggs, larvae, or nymphs of T. urticae. Gravid predatory mites (24–48 h old) were separately starved without water for 0, 24, 48, or 72 h before the bioassays. An adult female predator of each hunger level was then placed individually onto each bean leaf disc containing 30 eggs (0-24 h-old), 20 newly emerged larvae, or 20 newly emerged nymphs of T. urticae. After a 24 h feeding period, each predatory mite's prey consumption was separately counted for each stage. The effectiveness of N. californicus starved for 0, 24, 48, 72 h in controlling the T. urticae population was also determined on bean plants by comparing it to abamectin and an untreated control. The findings showed that hunger significantly reduced the consumption of prey eggs and larvae by N. californicus after 72 h of starvation. Conversely, N. californicus consumed more T. urticae nymphs at all starvation levels than when satiated. The results also showed that predators, deprived of food and water for 0, 24, and 48 h, effectively controlled the T. urticae population on bean plants, similar to abamectin. However, those without food and water for 72 h could not keep the population below the economic damage threshold during the experiment.