23 Kas 2024 Cumartesi
Seasonal abundance of Diaretiella rapae (M´Intosh) (Braconidae: Aphidiinae) parasitizing Lipaphis erysimi (Kaltenbach) (Hemiptera: Aphididae) in Brassica juncea variety Pusa bold
Abstract :The occurrence of Diaretiella rapae parasitizing Lipaphis erysimi in Mustard variety Pusa bold (Brassica juncea) was evaluated. Successful parasitism was 75.46% and 68.96% during 2006-07, 2007-08 respectively. Correlation coefficient of average per cent relative humidity with both aphid (r=-0.52) and parasitoid (r=-0.59) were negatively significant whereas day (r=0.65) and the night temperature (r=0.61) had significant positive correlations with the parasitoid population only. The best fitted polynomial regression equation indicated that 30-60% variability of the aphid population could be explained by the different weather parameters, while 11-50% variability of the parasitoid population could be explained by weather parameters.
Brassica juncea, Diaretiella rapae, Parasitism, Lipaphis erysimi, Seasonal abundance