Intrinsic Rate of Natural Increase, Life Table, Parthenium hysterophorus, Sunflower, Zygogramma bicolorata.
Abstract
Life-table of the Mexican beetle, Zygogramma bicolorata Pallister feeding on parthenium leaves, parthenium leaves smeared with sunflower extract, sunflower leaves and sunflower leaves smeared with parthenium leaf extract have been constructed. The longevity and intrinsic rate of natural increase (rm) varied with extract treated and their respective hosts. The intrinsic rate of natural increase did not change considerably when fed on parthenium leaves and parthenium leaves smeared with sunflower extract (rm=0.44). The beetles fed on sunflower leaves (rm=0.37) and sunflower leaves smeared with parthenium extract (rm=0.35) were also not very different. Shorter generation time was obtained when fed with parthenium and parthenium leaves smeared with sunflower extract.