Fumigation Activities Of Essential Oils Against The Plodia Interpunctella (Hübner) And Tribolium Castaneum(Herbst)

The study tested fumigation activity of14kinds of plant essential oil on Plodia interpunctella (Hiibner) larvae and Tribolium castaneum (Herbst) adults to select effective plant essential oils respectively; then measured fumigation toxicity under different concentration gradient and time gradient to analyze fumigation effects. According to the results of fumigation toxicity, we processed fumigation test under LC50and analyzed protective enzyme and detoxification enzyme activities in Plodia interpunctella larva and Tribolium castaneum adults under different fumigating period to discuss related biochemical mechanism.Finally, main ingredients in effective essential oils were obtained by GC-MS, and fumigation toxicity of main ingredients on Plodia interpunctella larva and Tribolium castaneum adult was tested. The results show as follows:1. Fumigant efficacies of the14kinds of essential oils on Plodia interpunctella larvae and Tribolium castaneum adults were investigated under the dosage of60μL/L and20μL/L respectively. The results indicated that different plant essential oil have significant difference and fumigation efficacy of Eucalyptus globules is better than other essential oils for larvae of Plodia interpunctella. When fumigation period was from24h to72h, mortality rate of larvae of Plodia interpunctella increased from84.45%to96.15%. The results about Tribolium castaneum (Herbst) adults indicated that fumigation efficacies of Illicium verum is better than other essential oils. And the mortality rate of adults of Tribolium castaneum reAchEd100%under20μL/L,24h. Methyl salicylate also have effective fumigation toxicity.When fumigation period was from24h to72h, mortality rate of the adults increased from67.77%to88.88%. Fumigation efficacies of plant essential oils on Plodia interpunctella and Tribolium castaneum vary from varieties of essential oils and exposure time.2. Further results of fumigation activity about Eucalyptus globulus and Illicium verum under different concentration gradient and time gradient showed as follows:After12h,24h,36h,48h,60h and72h Eucalyptus globulus treatment, values of LC50on larvae of Plodia interpunctella were55.16μL/L,51.48μL/L,48.13μL/L,44.43μL/L,41.74μL/L,38.20μL/L respectively and values of LC50on Tribolium castaneum adults after Illicium verum treatment were13.88μL/L,9.64μL/L,7.96μL/L,6.71μL/L,5.91μL/L,5.08μL/L respectively.3. The effects of three protective enzymes(SOD, POD and CAT) activities in Plodia interpunctella larvae and Tribolium castaneum adults were studied after the larvae and adults were fumigated with Eucalyptus globules oil and Illicium verum oil under LC50. The results showed that in the initial stage of fumigation(12h), the POD and CAT activity of Plodia interpunctella larvae were found rising and SOD activity was descending.As the extension of fumigation time, POD and CAT activity is inhibited and SOD activity is activated.And in the initial stage of fumigation(12h), the SOD, POD and CAT activity in Tribolium castaneum adults were found rising.As the extension of fumigation time, POD activity is inhibited.4. The effects of three protective enzymes(CarE、AchE and GSTs) activities in Plodia interpunctella larvae and Tribolium castaneum adults were studied after the larvae and adults were fumigated with Eucalyptus globules oil and Illicium verum oil under LC50. The results showed that in the initial stage of fumigation(12h), the CarE and GSTs activity of larvae of Plodia interpunctella were found rising and AchE activity was descending.As the extension of fumigation time, CarE and GSTs activity is inhibited and AchE activity is activated.And in the initial stage of fumigation(12h), the CarE and GSTs activity in Tribolium castaneum adults were found rising and AchE activity was descending.As the extension of fumigation time, AchE activity is inhibited.5. The main components in Eucalyptus globules and Illicium verum were confirmed by GC-MS. The study acquired13kinds of ingredients from Eucalyptus globules and the relative content of1,8-eucalyptus was52.61%;22kinds of ingredients from Illicium verum were found and the relative content of anethole was79.81%6. Further results of fumigation activity under different concentration gradient and time gradient showed as follows:After12h,24h,36h,48h,60h and72h1,8-eucalyptus treatment, values of LC50in larvae of Plodia interpunctella were37.95μL/L,34.55μL/L,30.73μL/L,28.15μL/L,25.31μL/L,21.82μL/L respectively and values of LC50in adults of Tribolium castaneum after anethole treatment were7.76μL/L,6.52μL/L,4.84μL/L,4.12μL/L,3.87μL/L,3.36μL/L respectively. The study indicated fumigation effect will strengthen along with extension of fumigation time and both dosage and exposure time affect the fumigation efficacies.