Study on the Growth Dynamic of the Gall of Aceria pallida Keifer
Objective:To study the development of galls infested by Aceria pallida Keifer on wolfberry (Lycium barbarum L.) during the spring,and provide a theory reference for population forecasting and field prevention of the mites.Methods:The external mcrphological alterations,the anatomical structure of galls and the population dynamics of mites were studied with the paraffin sections methods and the microsurgical technique.Results:The population dynamics of mites,the sizes and the microstructures of galls were studied.The results showed that in the initial period,the gall appeared yellow-green and the size increased quickly,but the number of mites in the galls increased slowly.The Mature galls were yellowish-brown,the gall size had no significant change.And the number of mites increased exponentially with the frequent phenomenon of mite migration.The galls were brown and broken,and a large number of mites began to migrate at the decline phase.The microstructures modifications were consistent show the loss of palisade tissue and spongy tissue surrounding nymphal chamber,the formation of a dense mass of uniform parenchyma cells and the chloroplast deletion.Conclusion:The sizes and the microstructures of galls are closely related to the population dynamics of mites,which could be used as references for population forecasting and field prevention of the mites.