Influence of elevated temperature on the fitness of Diamondback moth, Plutella xylostella (L.) in cauliflower

Abstract

Aim: To understand the effect of elevated temperature on the bionomics and fitness parameters of Plutella xylostella which would help in predicting the population growth rates and formulating appropriate management tactics. Methodology: In the present investigation, the fitness parameters of diamondback moth were studied at six different temperatures (31, 32, 33, 34, 35 and 36°C) in cauliflower in Open Top Chambers. Observations were recorded on the survival, longevity and fecundity at daily interval. The raw data on bionomics and life table parameters were analyzed using TWO-SEX- MS chart. Results: The total life cycle of P. xylostella was longer at 31°C and it declined with increasing temperatures. However, P. xylostella did not complete its development at 35 and 36 °C. The intrinsic rate of increase (rm) increased from 0.22 at 31°C to 0.28 at elevated temperature of 34°C. Temperature also had a significant effect on the net reproductive rate (R0), Gross Reproductive Rate (GRR) and finite rate of increase (λ). Interpretation: The fitness parameters will help to predict the change that occur in P. xylostella population due to climate change and global warming.