[Effects of cruciferous vegetables on experimental population of diamondback moth Plutella xylostella]

The impact of four species of cruciferous vegetables on the experimental population of diamondback moth (DBM) Plutella xylostella was evaluated in the laboratory. The results showed that there was no significant difference in total fecundity and longevity of DBM female moths reared on different crucifers. The population increase index of DBM reared on flowering Chinese cabbage, Chinese kale, leaf mustard, and pak-choi was 41.0, 69.5, 38.2 and 52.4, respectively, and the natural death at larvae stage was the most important factor influencing the population increase of DBM. The relatively lower natural death rates of larvae on Chinese kale and pak-choi contributed a higher increasing potential of DBM populations. It was concluded that among four species crucifers, Chinese kale could provide the most suitable nutrients for the development and reproduction of DBM population, and thus, it was considered as the best host of DBM. However, although leaf mustard has been reported as one of the most preferable host for DBM adult oviposition, it was not as better as three other crucifers for DBM development due to the higher natural death rate of larvae.