[Predatory and control ability of Orius minutus to the diamondback moth (Lepidoptera: Plutellidae).]

In order to make clear the suitability of eggs of Plutella xylostella as foodstuff of Orius minutus and the predatory and control ability of the bug to P. xylostella, the influence of praying on eggs of P. xylostella on development and reproduction of O. minutus was studied indoors with Myzus persicae as reference. The predation functional response was included to evaluate the control ability of O. minutus to P. xylostella. The results showed that O. minutus could finish its generation and reproduce offspring when fed on eggs of P. xylostella. The developmental durations of nymphal bugs (♀: 12.3 d, ♂: 12.2 d), the length of body of adult bugs [♀: (2.13±0.01) mm, ♂: (1.91±0.00) mm], the width of body of adult bugs [♀: (0.87±0.01) mm, ♂: (0.71±0.01) mm], the fecundity per female (12.7±1.1), the pre-oviposition period [(5.1±0.6) d] and the oviposition period [(3.7±0.4) d] all had no significant difference from those of treatment group of M. persicae; the longevity of adult bugs [♀: (10.7±1.4) d, ♂: (9.1±1.3) d] was longer than that of treatment group of M. persicae [♀: (8.5±0.5) d, ♂: (6.4±0.3) d]; the survival rate of nymphal bugs [(65.0±6.8)%] was lower than that of treatment group of M. persicae [(80.0±8.2)%], and the percentage of females was low. The predation functional responses of O. minutus to P. xylostella were all in accord with Holling2 equation. The largest amounts of caught per day (Nmax) of the 1st, 2nd, 3rd, 4th and 5th instar nymphal bugs to eggs of P. xylostella were 7.5, 16.3, 23.3, 29.1 and 38.7, respectively; the Nmax of the female and male adult to eggs of P. xylostella was 39.0 and 26.9, respectively; the Nmax of the 5th instar nymph to lower instar larva of P. xylostella was 41.3; and the Nmax of the female and male adult to lower instar larva of P. xylostella was 40.8 and 23.9, respectively. Single female and male pray eggs of P. xylostella up to (711.3±58.1) and (535.4±30.6), lower instar larvae of P. xylostella up to (371.9±52.0) and (253.9±32.3) during their whole lifetime, respectively. O. minutus could be reared with eggs of P. xylostella, and O. minutus has a good ability to control P. xylostella.