Method for breed conservation of mixed population of myzus persicae and aphidius gifuensis ashmead in northern winter and propagation method

The invention discloses a method for breed conservation of a mixed population of myzus persicae and aphidius gifuensis ashmead in winter in the north and a propagation method, and belongs to the technical field of biological prevention and control of agricultural pests. The invention provides a method for breed conservation of a mixed population of myzus persicae and aphidius gifuensis ashmead in northern winter, which comprises the following steps of: sowing host Chinese cabbages in a delayed manner, providing an activity space for the myzus persicae due to the fact that the core of the Chinese cabbages is not solid, inoculating field naturally-bred aphidius gifuensis ashmead as breeding bees, and storing the host Chinese cabbages with the mixed population of myzus persicae/aphidius gifuensis ashmead in a cellar, the breeding speed of myzus persicae/aphidius gifuensis ashmead is reduced under the low-temperature condition, and the problem of population degeneration caused by continuous breeding of multiple g