Department of Zoology, Loyola College, Chennai-600 034, Tamil Nadu (India).
Larvae of Culex mosquito and Chironomus, fingerlings of fish Tilapia, and frog tadpoles were used as prey species to verify prey preference by the water bug, Diplonychus indicus. Prey species were taken in combination of two's as 75:25, 50:50, 25:75, 20:30, 30:20 and 25:25. Prey death rate of frog tadpole was the least as 1.0 in combination with fish fingerlings (50:50) by fifth predator stage. The highest predatory efficiency was with Culex larvae in fifth predator stage killing 41.4 in combination with Culex larvae in the ratio of 50:50. Relatively fifth predator stage showed the highest predatory efficiency than the others with all prey species in combination. All predator stages preferred Culex larvae than the other prey species.
