FACTORS INFLUENCING THE PREDATORY EFFICIENCY OF Nepa cinerea LINNAEUS 1758 (HEMIPTERA: NEPIDAE) ON PREY Aedes albopictus SKUSE 1894 (DIPTERA: CULICIDAE)

The predatory efficiency of Nepa cinerea on Aedes albopictus larvae as prey was analysed based on various factors like prey instar and density, space size and vegetation density. The total number of prey intake at prey density number of 2, 4, 8, 16 and 32 was 3.9 ±1.5, 10.6 ±1.5, 21.0 ±1.9, 42.6 ±4.2, and 79.6 ±6.5 respectively. For, space size, the total number of prey intake by the predator at different volumes, viz., 1, 2, 5, 10 and 20L was 41.8 ±1.4, 35.6 ±0.7, 28.8 ±1.4, 22.1 ± 0.7, and 14.0 ±1.0 respectively. While for vegetation density at 1, 2, 3, 4, and 5g, the respective values for total number of prey intake was 39.5 ±1.7, 32.6 ±1.6, 29.5 ±1.1, 24.6 ±0.5, and 20.6 ±0.8. The present investigation gives an essential idea with respect to these factors which play a vital role in the variation of the predation efficiency of predators on their prey which are successful parameters in determination of concrete prey predator relationship.