Screening And Primary Field Evaluation Of Semiochemicals Manipulating Behavioral Responses Of Cytorhinus Lividipennis

Plant volatile semiochemicals have been shown to act as a key factor in the plant chemical defense.It plays an important role in regulating the tripartite nutrition relationships between plant,pests and natural enemies.It provides certain informations for the habitat selection of herbivores and the orientation of natural enemies.To study the regulation mechanism of plant volatile compounds on the behaviour of herbivores and their natural enemies is beneficial to explore the ecological function of plant volatiles.In this research,we screened several single and mixed rice volatile compounds attracting Cytorhinus lividipipennis in indoor test,and carried out field experiments.The test contents are below:1.Screening the single rice volatile compounds which attract Cytorhinus ividipipennisWe tested the olfactory response of Cytorhinus lividipipennis female adults to 0 kinds of single rice volatile compounds（α-pinene,linalool,E-2-hexenal,is-3-Hexen-1-ol,ocimene,Methylis salicylas,nerolidol,β-caryophyllene,enzene acetaldehyde and 2-heptanone）in 4 concentrations(100,10,1,0.1 mg/L^-1)used the T-tube olfactometer.Finally,we founded that 6 kinds of single rice olatilesα-pinene(100 mg L^-1),linalool(1mg/L^-1),E-2-hexenal(100,10,1,0.1 mg/L^-1),cis-3-Hexen-1-ol(0.1mg/L^-1),ocimene(1mg/L^-1)and Methylis salicylas 10mg/L^-1)can attract the female adults.Single rice volatile compounds which have the attractive effect to Cytorhinus lividipipennis female adults were mixed according to the optimal concentration in previous test,then we obtained 57 kinds of blends.Next we tested the olfactory esponse of Cytorhinus lividipipennis female adults to these blends.Finally we creened 5 kinds of blends which have the attractive effect:blend 7（Methylis alicylas 10mg/l+ocimene 1mg/l+linalool 1mg/l+E-2-hexenal 0.1mg/l+ is-3-Hexen-1-ol 0.1mg/l）,blend 28（α-pinene 100mg/l+ocimene 1mg/l+E-2- exenal 0.1mg/l）,blend 38（Methylis salicylas 10mg/l+E-2-hexenal 0.1mg/l+ is-3-Hexen-1-ol 0.1mg/l）,blend 41（ocimene 1mg/l+E-2-hexenal 0.1mg/l+ is-3-Hexen-1-ol 0.1mg/l）and blend 45（α-pinene 100mg/l+linalool 1mg/l）.2.Optimizing the proportion of blends and field trial2.1 Comparing attractive effect of blendsWe compared the attractive effect of the 5 blends screened,and the most effective attractant was blend 28（α-pinene 100mg/l+ocimene 1mg/l+E-2-hexenal 0.1mg/l）.2.2 Optimizing the proportion of blendsAfter fine-tuning the concentration of each single volatile component in blend 28,we obtained a ratio optimized blend 28-1（α-pinene 150mg/l+cimene 1.5mg/l+E-2-hexenal 0.1mg/l）,which have better attractive effect than efore.2.3 Field trialWe evaluated the effectiveness of blend 28 and each single component of it in field trapping trials.Finally we trapped 18 families insects,including 4 families of parasitic wasps（Thysanidae,Trichogrammatidae,Eulophidae,Aphelinidae）and 5 families pests（Thripidae,Delphacidae,Cicadellidae,Pyralidae,Tortricidae）;There are also a vast majority of 9 kinds of neutral insects.In this study,we tested the impact of several single and mixed rice volatile ompounds on the olfactory behavior of Cyrtorhinus lividipennis by indoor olfactory behavior test and field trapping,and we founded that there are some bioactive components in rice volatile compounds which could influce the olfactory behavior of Cyrtorhinus lividipennis.The results provided a theoretical basis for exploiting botanical attractant of Cyrtorhinus lividipennis.