Voltinism is a related term of univoltine.

In biology terms the difference between univoltine and voltinism

is that univoltine is having one brood or generation in a year while voltinism is the number of broods or generations of an organism in one year.

As an adjective univoltine

is having one brood or generation in a year.

As a noun voltinism is

the number of broods or generations of an organism in one year.