Utilization of Sentinel and Insect Lavae Homogenate-coated Mock Preys for Monitoring Predatory Behavior of Arthropods and Mammals at Tea Plantations

Objective Applicability and limitation of using sentinel prey to quantitatively monitor the predator pressure exerted on pest insects by arthropods and mammals on different vertical stratifications at tea plantations were investigated.

Method A field experiment was conducted in June 2024 to compare the rates of attacking two artificial preys hung on the ground and tea bush canopy levels by arthropods and mammals. A standard plasticine sentinel prey (SP) and a mock prey smeared with Ectropis grisescens larvae homogenate (CP) were used as the predatory targets. Bite marks left on the prey were recorded as predator’s attack rates.

Result The attack rate on CP by all predators combined was 41.67%, and that by arthropods 38.89%, which were significantly higher than those at 13.89% and 12.50%, respectively, on SP (χ² = 25.915, P＜0.001). But no significant predatory preference was displayed by mammals (χ² = 0.655, P=0.419). With respect to the hanging location, the two types of prey on ground level were attacked at significantly higher rate than in canopy by arthropods, mammals, or combined. Between the predators, arthropods significantly surpassed mammals on predation of SP or CP.

Conclusion Although monitoring applied SP underestimated the absolute predation on pest insects, it captured the relative spatial differentiations of the predatory behavior of arthropods and mammals in the agroecosystem of tea plantations.