Feeding Behavioral And Induced Metabolomics Responses Of Formosan Subterranean Termite, Coptotermes Formosanus

Coptotermes formosanus Shiraki is one of the most important harmful termites.The termite pest has both main nest and deputy nest,and it is very difficult to control the formosan subterranean termite because of their hidden lives.The main method of termite control currently is bait technology.It has potential value to be used intermite trapping system since the phagostimulating pheromone was found.The aim of this study is to select the antioxidants as synergist associating with termite phagostimulatingpheromone,hydroquinone.For comparing phagostimulating effect with different substances,the gas chromatography time-offlight mass spectrometry(GC-TOF-MS)of metabonomics was conducted to assay responses of metabolites based on the a result of experiments in which the C.formosanus workers fed on the cellulosic feedstock treated with hydroquinone and tea polyphenols.This study would provide the basic data for the development of termite baiting technology.The major results are summarized as following:1.Synergistic effect of antioxidants on hydroquinone as phagostimulant for C.formosanusButylated hydroxytoluene(BHT)and tea polyphenols as antioxidants were selected,and the selecting and feeding behavior of C.formosanus workers were analyzed in different ratios of antioxidants and hydroquinone mixing with filter paper.The results showed there was no significant synergistic effect with different BHT to hydroquinone ratios,while the mixture between 1 ng/?L hydroquinone and tea polyphenol in the mass ratio of 1:5 has significantly higher phagostimulating effect in both no-choice and choice experiments.2.Phagostimulating responses comparing with different foods to C.formosanusUsing the method of filter paper treated with 3% xylose solution,fresh milk,0.5% octadecyl gallate and the mixture(1 ng/?L hydroquinone and tea polyphenol in the mass ratio of 1:5)respectively,the orientation and feeding behavior of C.formosanus workers were analyzed.The results showed that there were significant phagostimulating effects to C.formosanus workers feeding on 3% xylose solution and the mixture solution,so that they all could be used to control C.formosanus.There was no significant phagostimulating effect with fresh milk,while 0.5% octadecyl gallate had a certain degree of repellency.3.Metabolomic analyses of Coptotermes formosanusIn this section,three different cellulose baits was made by mixing with ultrapure water,the mixed solution T'(1 ng/?L hydroquinone and tea polyphenol in the mass ratio of 1:5)and mixed solution T(1 ng/?L hydroquinone and tea polyphenol in the mass ratio of 5:1),respectively,then C.formosanus workers were fed on these baits for ten days.And,gas chromatography time-of-flight mass spectrometry(GC-TOF-MS)was conducted to assay the metabolic substances of the C.formosanus workers.The untargeted metabolomic analyses revealed that there were significant differences compared two treatments with control group,and total 53 and 54 different metabolic compounds were identified,respectively,under the variables the VIP(Variable Importance in the Projection)values exceeding 1.0,P-value less than 0.05(Student's t-test),and similarity values more than 200.The different metabolites of treatment T' compared with the control group including: 2 amino acids(glutamic acid and cycloleucine)were down-regulated,while 7 amino acids(oxamic,3-hydroxynorvaline and so on)were up-regulatad;2 esters(gluconic and D-erythronolactone)were down-regulated,while 4 esters(methyl phosphate,glucose-1-phosphate and so on)were up-regulatad;5 sugars(ribose,sophorose and so on)were up-regulatad;and other 6 metabolites were downregulated,while fatty acids,hormones and other 27 metabolites were up-regulatad.There were 6 relevant metabolic pathways in this analysis as follows: fatty acid biosynthesis,biosynthesis of unsaturated fatty acids,glycine,serine and threonine metabolism,arginine and proline metabolism,tryptophan metabolism,and ABC transporters.The different metabolites of treatment T compared with the control group included: 6 amino acids(proline,glutamic acid,cycloleucine and so on)were down-regulated,while 3 amino acids(3-hydroxy-L-proline,3-hydroxynorvaline and D-alanyl-D-alanine)were up-regulatad;4 esters(methyl phosphate,glucose-1-phosphate and so on)were up-regulatad;maltose,mannose and erythrose were down-regulated while 6 sugars(ribose,sophorose and so on)were up-regulatad;and other 9 metabolites down-regulated while fatty acids,alcohols,hormones and other 23 metabolites were up-regulatad;there were 13 metabolic pathways correlatively in this analysis as follows: glycolysis/gluconeogenesis,fructose and mannose metabolism,starch and sucrose metabolism,galactose metabolism,fatty acid biosynthesis,biosynthesis of unsaturated fatty acids,glyoxylate and dicarboxylate metabolism,2-oxocarboxylic acid metabolism,biosynthesis of amino acids,glycine,serine and threonine metabolism,arginine and proline metabolism,ABC transporters,and carbon metabolism.