bivoltine

A breed of mulberry silkmoth which produces two generations per year and lays hibernating and non-hibernating eggs.  The monovoltine silkmoth produces one generation per year and multivoltine or polyvoltine up to eight generations per year.  Multivoltine or polyvoltine are tropical varieties which, unlike bivoltine or monovoltine from temperate regions, have no dormant period. See monovoltine, multivoltine and polyvoltine.