Control Effects Of Plant Extracts On The Striped Flea Beetle, Phyllotreta Striolata

The plant extracts of non-host plants on the pests of the striped flea beetle (SFB), Phyllotreta striolata (F.) were studied. The plant extracts of non-host plants play an important role on protecting the target plants, including the effects of adult deterrents and adult antifeedants. Based on these studies, the three deterrent extracts of effective bioactivitions were found out on purpose. And interactions of adult deterrents among the plant extracts were studied; And then the control effectiveness of the 3 extracts in the field were studied, based on the index of population control for the ecological control of SFB in vegetable fields.In the adult deterrent assay, when applied with 24 kinds of non-host plant extracts, the leaf areas consumed by SFB adults were singnificantly different (a =0.01 or 0.05, Ducan's multiple range test) from that on the control. The deterrent rates also varied among different treatments. The results showed that N.tabacum, Nicotinamide, A.argyi, S.media and B.variegata had a strong deterrent effect. The rates of the deterrents were between 84.45% and 98.79%, while the others were much less within 72 hours after treatment. There were only 7 extracts with the toxicity in 24 extracts. And the rates of toxicity were very low. And they were higher than the others. The antifeedant effects of 24 plant extracts of non-host plants on the adult of SFB were tested. The results showed that under the selective antifeedant, Z.bungeanum, Lsativa, H.scandens, Nicotinamide, N.tabacum and A.conyzoides had a stronger antifeedant effect than the others within 48 hours after treatment, the rates of that were between 81.28% and 100.00%; Under the no selective antifeedant, S.media and N.tabacum had a strongest antifeedant effect. The rates of the antifeedant were between 81.37% and 100.00% within 48 hours after treatment.Based on the orthogonal-regression-rotation design, the model was developed, which revealed the interactions among the extracts of the non-host plants with the property of deterrent of the adults. The model of adult deterrents showed that extracts of N.tabacum and D.repens had a synergistic interaction of deterring adult (P<0.2000, One-Way ANOVA) and H.scandens extracts had an antagonistic interaction of deterring adult with D.repens or N.tabacum.Based on the index of population control, an index system was suggested to evaluate the effects of plant extracts of non-host plants on population control of SFB. The control effectiveness of the 3 extracts on SFB was investigated. The results showed the control mechanism of the ones on SFB population was a little effective deterrent effect in the fields.