The bottom-up effect of different host plants on life table parameters of Plutella xylostella (Lepidoptera: Plutellidae)

The diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae), is recognized as the major pestof crucifer plants worldwide. Canola, Brassica napus L., as an oil recourse is widely grown. Investigationon comparative demography of P. xylostella on five commercial canola cultivars namely Star, Elite,NSA2, SLM and RGS with arugula, Eruca sativa Miller, was the main purpose of this study. Thelife table parameter including the net reproductive rate (R0), intrinsic rate of natural increase (rm), finiterate of increase (λ), mean generation time (T), and doubling time (DT) were determined on the mentionedhost plants in laboratory conditions at 25±0.5˚C, 65±5% RH and a photoperiod of 16:8 (L:D) h. Thecomparison of rm (0.249 Day-1), λ (1.24 Day-1) and DT (2.91 Day) of P. xylostella suggested that this pestperformed best on SLM. The values of the life table parameters of R0 (8.56 female/female/generation),rm (0.143 Day-1), λ (1.15 Day-1) and DT (5.35 Day) obtained on arugula indicated that this plant was moreresistant than the commercial cultivars of canola examined. The life table parameters of P. xylostella onRGS and arugula did not show significant difference, except in mean generation time. The results ofthis study revealed that host plant can greatly affect performance of P. xylostella. Knowledge on resistantand partially resistant host plants helps us to use them in IPM programs.

Keywords:

Diamondback moth , Canola , Arugula , Life table