Pieris rapae is another famous Pieris rapae, also known as Pieris rapae larva, which is the most widespread, harmful and often disastrous pest in China. There are 9 families and 35 species of known host plants, all of which belong to Cruciferae.

I especially prefer Chinese cabbage, cauliflower, cabbage and radish with thick leaves. In the absence of Cruciferae plants, other host plants can also be eaten, such as Compositae, Saussurea, Liliaceae, Lycaceae, Oleaceae and other plants.

Pieris rapae occurs everywhere, with different generations every year and increasing gradually from north to south. Northeast China 1 year 3-4 generations, Huanghuai area 5-6 generations, Yangtze River basin area 7-9 generations, Guangzhou area about 12 generations. There is no diapause in South China, and all insect states can overwinter.

Extended data:

The emergence time of overwintering pupae varies greatly across the country, from February to April in North China, from April to May in Northeast China and from May to June in Northeast China.

Due to the complex environment and large temperature difference of overwintering pupae, the emergence period of overwintering adults is long, which can be as long as one month. This is the main reason for the overlapping of generations in the field in the future, and it also brings some difficulties to prediction and control.

The peak period of disasters varies from place to place in a year. It occurs twice in late spring, early summer (April-June) and early autumn (9-165438+1October) in the south, May-June and August-September in the north and July-September in the northeast.