Action thresholds to aid pest population management decision-making of 11 categories of wet rice arthropods are suggested in terms of mean population density per hill ( x ) and proportion of infestation (P(1)) of the field sampling units. The thresholds are the (x) and P (I) values at the point of saturation of a polynomial regression curve obtained by plotting (x) against P(I) for each arthropod category. The respective values for pests are: 3.38, 0.92 (Nephotettix spp.), 6.28, 1.00 (Nilaparvata lugens), 1.37, 0.72 (Cnaphalocrocis medinalis- Pyralidae), 2.42, 0.90 (Recilia dorsalis), 3.81, 0.97 (Sogatella furcifera), and for predators are: 3.89, 0.98 (Cyrtorhinus lividipennis), 2.39, 0.85 (Anatrichus pygmaeus- Diptera), 2.02, 0.82 (Odonata), 1.65, 0.81 (Casnoidea spp), 1.61, 0.64 (Paederus fuscipes), and 1.60, 0.69 (spiders). P(I) is significantly (P<0.001) affected by arthropod category and growth stage of the crop. The observed P (I) indicated high fits (most i2>0.90) to clumped- and Poisson-based distribution models.