Comparative Life Table Analysis of Plutella xylostella (L.) (Lepidoptera: Plutellidae) on Different Brassica Hosts

Abstract

The study was conducted to determine the effect of different brassica hosts (cabbage, cauliflower, and red cabbage) on the life table of Plutella xylostella (Lepidoptera: Plutellidae) (Linn.) under the laboratory conditions (26 ± 2°C temperature, 65 ± 5% relative humidity, and 14 L:10 D photoperiod). The findings revealed that the age-specific, stage-specific, and female fertility life table was significantly influenced by brassica hosts. The longest survival and shortest life expectancy were observed on red cabbage, while the shortest survival was on cabbage and the longest life expectancy on cauliflower. The maximum survival rate and lowest mortality were found on cabbage, followed by cauliflower and red cabbage, respectively. The mortality was recorded highest in the pupal stage on all hosts. While within the larval stage, the maximum mortality was recorded at the 1st instar on red cabbage and the 3rd instar on cabbage and cauliflower. However, the generation mortality was increased on red cabbage while decreased on cabbage and cauliflower. The potential fecundity (Pf) and net reproductive rate (Ro) were highest on cabbage (105.99 and 23.55 females/female/generation), followed by cauliflower (77.58 and 15.50 females/female/generation), and lowest on red cabbage (12.79 and 3.57 females/female/generation). However, both mean and corrected generation time (Tc and τ) were shortest for cabbage (24.97 and 24.78 days) and longest for red cabbage (31.46 and 31.45 days). The population of P. xylostella was double with a minimum time duration on cabbage (5.48 days), while the maximum time duration was on red cabbage (17.12 days). The intrinsic rate of increase, finite rate of increase, and monthly rate of increase were found to be maximum on cabbage and minimum on red cabbage, while medium on cauliflower. Based on experimental findings, we conclude that the cabbage was a favorable host for the growth and development of P. xylostella, followed by cauliflower.