Effects of chinaberry fruit extract on feeding, growth and fecundity of the diamondback moth, Plutella xylostella L. (Lep., Yponomeutidae)

Abstract

Effects of chinaberry fruit extracts on larval mortality, feeding inhibition and reproduction of the diamondback moth (DBM), Plutella xylostella L., were investigated by feeding DBM larvae on treated leaves or seedlings. These extracts were found to be toxic to DBM larvae. The larvae usually died from failure in molting. The developmental growth rates and the food consumption were also reduced at concentrations of 2.0 and 4.0%. Chinaberry extracts reduced pupal weight, adult emergence and longevity in a dose-dependent manner when newly hatched larvae were continuously reared on treated rape seedlings at concentrations of 0.05% or above. Fecundity of the resulting females from the larvae treated with 0.5% extract was also reduced, while the egg hatch was not affected. However, the extracts significantly decreased egg hatch when the eggs were dipped directly into test solutions at 1.0% or above.