Identification Of A Aggregation Pheromone In Trigonorhinus Sp. And Its Biological Activity

In this study,the existence of aggregation pheromone of Trigonorhinus sp.was proved by laboratory tests.This study confirmed through the use of a Y-type olfactometer that males can release certain volatile compounds to attract bisexual adults.Subsequently,we used two pheromone extraction methods to extract the compounds from the body and feces of the male at different development stages,and separated and identified them through two chemical analysis techniques,and predicted the chemical structure of the active compounds.Finally,the biological activity and originated area of synthetic aggregation pheromone were verified by laboratory behavior test and indoor anatomy technology.The results are as follows:(1)Using a Y-shaped olfactometer,the olfactory selection behavior of indoor Trigonorhinus sp.was measured for female and male body and fecal odor sources in the early stages of emergence,non mating,and mating stages.The results showed that except for the early stage of emergence,both the male body and feces of Trigonorhinus sp.can release certain volatile information compounds,causing significant positive trend behavior in both male and female adults.However,the female body and feces of female adults cannot produce information compounds with the same effect.(2)Extract the volatiles from the unmatched and already mated stages of Trigonorhinus sp.males using the HS-SPME method,and obtain extracts from the unmatched and already mated stages of Trigonorhinus sp.males and their feces using solvent extraction.Obtain compound information using GC-MS.The results showed that among the compounds collected through two methods,a total of 27 compounds were identified in the male insect body during the non mating period,and 22 compounds were identified in the male insect feces.During mating,a total of 28 compounds were identified in male insect bodies,and 24 compounds were identified in male insect feces.(3)GC-EAD was used to detect the activity of male body and fecal extracts of Trigonorhinus sp.during the non mating and mating stages.The results showed that2,6,10,14-Tetramethylheptadecane and Heptacosane had a more significant effect on the tentacles of the Trigonorhinus sp..Among them,2,6,10,14-Tetramethylheptadecane was found in the body and feces of male insects during both non mating and mating stages,and Heptacosane is only found in the body and feces of male insects during the mating period.(4)By using mass spectrometry,GC-MS was used to compare the mass spectra of standard samples obtained from the mass library,natural information compounds,and chemical standards.The results showed that the natural information compounds of2,6,10,14-Tetramethylheptadecane and Heptacosane had similar peak patterns of fragment ions in the chemical standard spectra,while the relative abundance of fragment ion peaks in the mass spectrometry was roughly the same.Explain that the natural information compound composition is consistent with the chemical standard.(5)The olfactory selection behavior of Trigonorhinus sp.on the concentration gradients of 2,6,10,14-Tetramethylheptadecane and Heptacosane was measured using a Y-type olfactometer.The results showed that the 2,6,10,14-Tetramethylheptadecane and Heptacosane can cause significant positive trend selection behavior in the bisexual adult was 0.01 ng/μL-1 ng/μL.The dose range of the significant positive trend selection behavior induced by Heptacosane in males is larger than that in females.Where 0.01 ng/μL concentration of 2,6,10,14-Tetramethylheptadecane has the best attraction rate for male and female adults and 0.1 ng/μL concentration of Heptacosane has the best attraction rate for male and female adults was 0.1 ng/μL.(6)In order to determine the production site of aggregation pheromone of Trigonorhinus sp.male,the volatile substances in 12 insect body parts of the male were determined by solvent extraction and GC-MS.The results showed that Heptacosane was only found on the abdominal epidermis of male worms,and no aggregated pheromone component was found in other parts.