Study On Octopamine Analysis And Function In Holotrichia Parallela

Holotrichia parallela is a worldwide important underground pest with a wide range of food. The larvae feed on the roots of the host plants, tender stems and other underground tissues, and the adult beetles take on the leaves and flowers of the host plants. Recently, with the change in the no tillage cropping pattern, the occurrence of H.parallela in our country has being more and more serious, which caused great damages. At present, along with the concern on pesticide residues, food and environmental safety, biological control is becoming more and more important in the control of underground pests. Sex pheromone has been developed and applied in field control of H.parallela as an important means of biological control. It is found that there is a synergistic effect of plant volatiles to sex pheromone.The author studied the role of octopamine in growth and reproduction, revealing the mechanism of regulation of octopamine, and providing the basis of synergistic mechanism.First of all, I established a simple, efficient and fast determination method. Then the content and distribution of octopamine were analyzed in H.parallela. Finally, using physiological and ecological methods analyzed octopamine effect on H.parallela survival rate, mating, oviposition and hatchability. The major results are listed as follows:(1) The author established a method using HPLC to analyze octopamine content in H.parallela neural tissue. The results of method validation showed that the regression equation has a significant positive correlation, octopamine in the test sample was stable in 24 h and a good reproducibility, the average recovery rate was 102.23%.Therefore, the method can be used to determine the content of octopamine in H.parallela nerve tissue.(2) There are significant differences of octopamine content in different growth stages, different gender and different nerve tissue in H.parallela. Between male and female adults, octopamine content in the brain and abdominal ganglia tissue in the early stage of oviposition of females were significantly higher than males, but in the thoracic ganglia was significantly lower than that of the male, in the late stage of oviposition, octopamine content in brain tissue was significantly higher than that of male, and in the thoracic and abdominal nerve tissue were significantly lower than those of the male.(3) Determination of octopamine on male sex pheromone positioning ability and selectivity by Y-olfactometer,which showed that 2 μg/mL octopamine treatment can significantly improve the positioning capability of male H.parallela, selection coefficients on the sex pheromone was significantly higher than that of the control group, and its antagonist, mianserin, impaired the effect.(4) Octopamine can significantly improve the H.parallela adult female single day fecundity, and prolong the spawning period. Daily fecundity per female of the treatment fed on 2 μg/mL octopamine is 2 times higher than that of the control group on fecundity of female, when the control group stopped spawning, octopamine treatment group remains spawning. Octopamine had no significant influences on longevity both male and female, while mianserin prolonged the longevity of H.parallela. Different concentrations of octopamine and its antagonist’s treatments had no significant effect on egg hatching.