Potential of different species of winter cress (Brassicaceae) as dead-end trap crops for diamondback moth (Lepidoptera: Plutellidae)

Abstract: Dead-end trap crops are a particular type of trap crops that are highly attractive to the target insect pest, but do not allow its survival. Different Barbarea spp. (Brassicaceae) were compared to study their potential as dead-end trap crops for diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae). Barbarea plants were assessed based on the content of glucosinolates, which can stimulate oviposition in P. xylostella; and the content of saponins, which are detrimental to P. xylostella larvae. All Barbarea plants tested were preferred over cabbage and broccoli by ovipositing P. xylostella. Among Barbarea plants, few significant differences in oviposition preference by P. xylostella were found. Despite containing a lower content of saponins than other Barbarea plants tested, B. verna did not allow survival of P. xylostella larvae. Our study shows that, except for B. rupicola, which allowed survival of P. xylostella larvae, all Barbarea plants tested have potential as dead-end trap crops for P. xylostella when used with a crop of broccoli or cabbage.