Identification Of Brood Pheromone Of Bombus Terrestris (Hymenoptera:Apidae) And Its Ethological Effects

The bumblebees belong to Apidae in Hymenoptera.They play very important roles in maintaining plant diversity and ensuring the normal reproduction of plants,and are the important pollinators of crops in China and abroad.The purpose of this thesis is to study the chemical pheromone produced by the bumblebee(Bombus terrestris)offspring and causing the incubating behavior of worker bees.We took Bombus terrestris as the research target,established a quantitative research model of bumblebee worker’s incubating behavior,designed experiments to determine the source and nature of the bumblebees’ brood pheromone and its influence on workers’ behavior.The surface substances of bumblebee larvae and pupae were collected and identified,and then the behavioral effects of bumblebee workers were determined using the screened chemical components.The results of this study provide theoretical bases for improving the health levels of bumblebee larvae and pupae,and further exploring the basis of the labor division and the altruistic behavior of bumblebees.The main research results are as follows:1.After confirming that incubating behavior of bumblebee can significantly increase pupal temperature,we eluted or not eluted the pupae and cocoons of bumblebees with absolute ethanol,and the duration and frequency of incubating by bumblebee workers were observed by video recording.The results showed there are brooding pheromones from pupae and cocoons,which were released from pupae epidermis,gradually accumulated on the cocoons and initiate bumblebee workers to sense the signal and then to perform the incubating behavior for pupae.We used absolute ethanol to elute larvae,pupae,cocoons and nest-top wax,and then concentrated and added back the ethanol-eluted cocoons(containing dummy pupae),the duration and frequency of worker bees incubating the cocoons added with larvae,pupae and cocoons concentrate were significantly higher than those of absolute ethanol-eluted cocoons(P<0.05).However,there was no difference in the duration and frequency of incubating between the cocoons added with nest-top wax concentrate and the cocoons after ethanol elution,indicating that there are brood pheromones from larvae,pupae and cocoons that can induce the incubating behavior of workers,but there are no brood pheromones in nest-top wax.2.Starved larvae,pupae,cocoons and nest-top wax were eluted with absolute ethanol and then the elutes were concentrated.After GC-MS analysis of the eluates,a total of 49 prime compounds from larval surface were obtained,including alkanes,olefins,acids,esters,ketones and other substances.We checked the common substances contained in the body surface of larvae and pupae and the compounds and their contents in cocoons and the nest-top wax,the substances related or unrelated to bumblebee care were screened out.A total of 9compounds that may be related to bumblebee incubating behavior were obtained and their quantitative analysis were performed using the internal standard method.3.According to the quantitative and adding-back bioassay results,the mixture of tetroxide tetroxide,tetroxide acetate,ethyl palmitate and ethyl linolenic acid in the proportion of 46:21:9:1 and adding the mixture to dummy cocoons and pupae can significantly induce the incubating behavior of worker bees,it raises the surface temperature of pupae in the nest so that they can develop normally and rapidly within a suitable temperature range.