Giant water bugs (Heteroptera: Belostomatidae) are dominant group of aquatic predators of freshwater habitats, have received little attention in the Oriental region. These aquatic carnivorous bugs feed on dipterans larvae, small fishes, aquatic snails and tadpoles. Present Study was conducted to check the influence of temperature on feeding behavior of all the instars of the widespread Oriental belostomatid species, Diplonychus rusticus (Fabricius). To check feeding behavior Chironomus larvae provided and result is observed at five different temperatures conditions including 15^oC, 20^oC, 30^oC, 35^oC and 37.5 ^oC respectively. The temperature for the control was 25^oC. The feeding efficiency of each nymphal instar was calculated in terms of the average number of larvae consumed per hour. Present study suggested that when the temperature is decreased to 15^oC and 20^oC the rate of feeding is decreased and when temperature increased at 30^oC, 35^oC the rate of feeding behavior increased. Below 11^oC and above 37.5^oC the bug was unable to survive. This variation in the temperature influences the feeding behaviour of the Diplonychus rusticus Fabricius.