| Plutella xyllostella（Linnaeus）,belonging to the Insecta,Pterygota,Lepidoptera,Plutellidae,and is an important pest of cruciferous crops and it has more than 40 hosts.As a result of the large number of breeding of DBM,the generation of short,fast mutation,easy to producepesticideresistance,for a long time,control of diamondback moth mainly rely on the extensive use of pesticides,affecting the quality and safety of agricultural products,bringing environmental pollution and other issues.It is necessary to developenvironmental protection technology to control diamondback moth.In order to develop new techniques of radiation control ofDBM,in this study,the effects of 60Co-γirradiation on the growth and development of eggs and larvaeand the lethal and sterile effects on pupae and adults of DBM were studied.The aim was to scree n out the most effective sub-sterility dosefor males.The response of the sterile males to the sexual pheromone of the normal females,the flight capacity and the mating ability of the sterile males were tested to assess the flying quality of the sterile males.Sterile male and normal female indoor matching competition was set and the purpose was to get the male sterile sexual competitiveness index and the best release ratio.The aim of the fieldsmall cage experimentwas to evaluate the feasibility of Sterile Insect Technique controllingdiamondback moth.The effects of optimal sub-sterile dose irradiation on the activities of antioxidant enzymes and the expression of heat shock protein（HSP）in six-day-old pupae of diamondback moth were also studied.The results showedthat irradiation had a significant effect on the growth and development of eggs,larvae,pupae and adults ofdiamondbackmothwhich haddose-dependent effect.300 Gy irradiation dose could completely prevent the growth and development of eggs and 1-3 instar larvae,while the 4th instar larvae could develop to adult andcumulative survival rate was 1.33%.The sixth day pupae of diamondback moth were irradiated at the dose 250Gy,the eclosion rate was 55.33%and the deformity rate was33.84%.The survival rate on the 13th day after treatment with 250 Gy or more doses was 0.The sixth day pupae of diamondback mothwere treated with 150 Gy,200 Gy,250 Gy,the oviposition rate of adults,the hatching rate and pupation rate of F1 generation decreased with the increase of irradiation dose.The ratio of male to femalewas the largest and significantly larger than that of control group with 200 Gy.The fecundity of F1 was decreased with the increase of irradiation dose,and the pupation rate of F2 generation was significantly lower than 150 Gy with 200 Gy and 250 Gy,and there was no difference between 200 Gy and 250 Gy.Thus,200 Gy was the optimal dose for the treatme nt of male sterility.The results of the indoor evaluation of the irradiated male flying quality showed that the sixth day pupae of DBM were treated with 200 Gy,the irradiation of male flight ability,mating ability,the ability of female sex hormones were not affected by irradiation.The sexual competition and the optimal release ratio of the irradiated male showed that whenradiated male:wild male:wild female was 5:1:1,the sexual competition index was0.51.The competitive index did not change significantly with the increase,the treated males and wild males had the equal competition when mating with the wild female.This was shownthat the optimal release rate of the irradiated male was 5:1:1.Field release experiments showed that the number of F1 and F2generation population in the irradiated area was significantly lower than that in the control area,and the feasibility of Sterile Insect Technique controlling diamondback mothwith 200 Gy.The gene expression and enzyme activity of SOD,CAT and POD were significantly changed and the gene expression of HSP70swere significantly up-regulated by irradiation,indicating that SOD,CAT,POD and HSP70sdid play a role in the process of irradiation stress of diamondback moth. |
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