Aquatic Entomology & Biocontrol Research Laboratory, P.G. & Research, Department of Zoology, Loyola College, Chennai - 600 034, Tamil Nadu, India.
Studies on the survival rate of the belostomatid bug, Diplonychus rusticus (Fabr.) through immature stages varying in relation to their feeding efficiency with different preys revealed that the predation rates were not constant. The predatory rate of the instars and adults were found to be high for the larvae of Culex quinquefasciatus and Chironomus. The male recorded a highest predation rate of 83 ± 6 for Culex quinquefasciatus larvae while the female recorded a feeding rate of 79 ± 5.21. Instars and female predators showed a preference for Chironomus larvae with the V instar recording 69.6 ± 7.74 and the female recording high predatory rate of 81.2 ± 4.86 whereas, male predators preferred C. quinquefasciatus larvae. The survival rate for males and females was higher with C. quinquefasciatus than the other prey type. The male and female bugs survived for 40 days when fed with C. quinquefasciatus larvae and for 39 days when fed with Chironomus larvae.
