Life Table and Nutritional Ecology of <i>Epilachna vigintioctopunctata</i> Fab. (Colioptera: Coccinellidae) on Three Host Plants

Abstract

Host preference in relation to life table parameters and nutritional ecology of Epilachna vigintioctopunctata Fab. were studied under laboratory conditions. The pest, E. vigintioctopunctata showed more feeding preference and higher reproductive growth to its host plant, Solanum melongena followed by S. nigrum and Momordica cochinchinensis . The developmental duration of their neonates was shorter with higher adult longevity, fecundity, hatchability, and accumulated survivability in S. melongena followed by S. nigrum and M. cochinchinensis . The feeding indices and population parameters of E. vigintioctopunctata were significantly higher (P < 0.05) on S. melongena relative to the other host plants. The pest on S. melongena has shorter mean generation time (T c ) of 59.10 days with higher net reproductive rate (R 0 ) of 16.63. Their generation survival (GS) on S. melongena (0.582) is significantly higher than S. nigrum (0.568) and M. cochinchinensis (0.550) with reverse of total generation mortality (K) of 0.290, 0.308 and 0.376, respectively. These differences in the nutritional ecology and demographic parameters are due to the variation in their phytochemical regime of respective host plants. Thus, the study may help to find the most vulnerable stage (egg and pupal stage) of this pest for appropriate control measures and also supports the use of S. nigrum as an alternative host towards S. melongena and as a trap crop towards M. cochinchinensis to avoid or minimum invasion of this pest for sustainable agriculture.