Fig. 2

Seasonal population dynamics M. separata moths during 2014–2017. A Phenology of M. separata moths showing peaks that correspond to either migrants or emerged from local breeding. The whole migration circuit can be divided into four waves, and the fourth migration wave in the G4 period (from 16 August to 30 September) was the major southward migration as shown by increase of catches in the Yangtze Valley and South China. B The population increased through the first three migration waves. C The moth catches in the southern searchlight traps (to the south of 33° N) during G4 periods (S-G4) were much less than those in the northern searchlight traps (N-G4), and even less than those in the southern searchlight traps in spring (S-G1), indicating that most moths failed to reach overwintering areas during southward migration