The larvae develop rapidly with several generations in a year; however, some species may take up to 3 years to develop, and exceptional examples like Gynaephora groenlandica take as long as seven years.
As larvas desenvólvense rapidamente e adoita haber varias xeracións delas nun ano; porén, algunhas especies poden tardar 3 anos en desenvolverse, e un exemplo excepcional é Gynaephora groenlandica, que tarda sete anos.