Organic farming practice has been shown to promote biodiversity and natural enemies compared to conventional one. However, whether the changes in species composition translate into a difference in trophic niches and ecosystem service (biocontrol) remains unclear. In this study, we examined the effects of organic and conventional farming practices on arthropod prey-predator trophic interactions in rice paddy farms in Miaoli, Taiwan. We sampled the arthropod communities over the course of crop season and analyzed their stable isotope signatures (13C and 15N) to determine the isotopic trophic niches of generalist arthropod predators (spiders and ladybugs). Bayesian stable isotope mixing models were constructed to quantify the dietary proportions of predators from potential prey sources  We found no distinct differences in the feeding ecology and trophic niches of generalist arthropod predators between organic and conventional farms. Specifically, these predators mainly consumed rice-associated herbivores, highlighting their value in biocontrol in both organic and conventional farms. Taken together, our findings suggest that generalist arthropod predators can exert top-down effect on herbivorous pests in both organic and conventional rice paddies.