Voltinism is a term used in biology to indicate the number of broods or generations of an organism in a year. The term is particularly in use in sericulture

Sericulture

Sericulture, or silk farming, is the rearing of silkworms for the production of raw silk.Although there are several commercial species of silkworms, Bombyx mori is the most widely used and intensively studied. According to Confucian texts, the discovery of silk production by B...

, where silkworm varieties vary in their voltinism.

• Univoltine - (adjective) referring to organisms having one brood or generation per year
• Bivoltine - (adjective) referring to organisms having two broods or generations per year
• Multivoltine - (adjective) referring to organisms having more than two broods or generations per year
• Semivoltine - (adjective) referring to organisms whose generation time is more than one year

Evolution

The number of breeding cycles in a year is under genetic control in many species and they are evolved in response to the environment. Many phytophagous species which are dependent on seasonal plant resources are univoltine. These species also have the ability to diapause

Diapause

Diapause is the delay in development in response to regularly and recurring periods of adverse environmental conditions. It is considered to be a physiological state of dormancy with very specific initiating and inhibiting conditions...

.