Females begin laying eggs right after their first mating, & both sexes will mate several times during their lives. Adults in summer generations live from 2-5 weeks. Each year, the final generation of Monarchs, which emerges in late summer and early fall, has a job: to migrate to overwintering grounds, in central Mex for east Monarchs or in Cali for western Mon. Here they survive the long winter until conditions in the US allow them to return to reproduce. adults can live up to 8-9 months.