Population Dynamics and Correlation Analysis of Wheat Aphids and Their Natural Enemies

Abstract To investigate the population dynamics and correlation between wheat aphids and their natural enemies, we conducted a checkerboard sampling study in Yantai, Shandong province from 2019 to 2022. The main types of wheat aphids observed were S. miscanthi and Rhopalosiphum padi. S. miscanthi was found to occur on May, while R. padi appeared on June. The population dynamics of S. miscanthi followed a parabolic pattern, with peak numbers reached in mid-to-late May, followed by a decline. Similarly, the population of mummified aphids also exhibited a parabolic trend, and there was a linear correlation between the number of mummified aphids and S. miscanthi. However, mummified aphids appeared 4–10 days later than S. miscanthi. Furthermore, the occurrence trends of wheat aphids and their natural enemies generally aligned with each other, except in 2020 when the natural enemies emerged 10 days later than wheat aphids. This indicated a clear follow-up relationship between mummified aphids and S. miscanthi, as well as an evident following relationship between the natural enemies and wheat aphids. In conclusion, our study highlights the interplay of population dynamics among wheat aphids, mummified aphids, and their natural enemies in the Yantai region. These findings can contribute to a better understanding of ecological interactions in agricultural ecosystems and potentially aid in the development of integrated pest management strategies.