# Net reproductive rate (R0)

> The average number of female offspring a female produces in her lifetime after mortality: the population's multiplication per generation.

- Canonical: https://genetixbay.com/knowledge/glossary/net-reproductive-rate.html
- Also written: R0, net reproduction rate
- Glossary category: Pests and diseases · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

The net reproductive rate, R0, is how many daughters an average newborn female will leave, accounting for the chance she dies first. If R0 is 40, the population multiplies 40-fold each generation. It is calculated from a [life table](https://genetixbay.com/knowledge/glossary/life-table.md) by summing survival times daughters at each age.

## In practice

R0 and r_m are linked through [generation time](https://genetixbay.com/knowledge/glossary/generation-time.md): r_m is approximately ln(R0) divided by the mean generation time T. A pest with modest R0 but very short generations, like a [spider mite](https://genetixbay.com/knowledge/glossary/two-spotted-spider-mite.md) at 30 C, can outgrow one with a higher R0 and slow generations, like a [mealybug](https://genetixbay.com/knowledge/glossary/mealybug.md).

## Don't confuse with

- **r_m**: per day, not per generation.
- **Fecundity**: eggs laid, before mortality and [sex ratio](https://genetixbay.com/knowledge/glossary/sex-ratio.md).

## Related terms

[Intrinsic rate of increase (r_m)](https://genetixbay.com/knowledge/glossary/intrinsic-rate-of-increase.md), [Life table](https://genetixbay.com/knowledge/glossary/life-table.md), [Generation time](https://genetixbay.com/knowledge/glossary/generation-time.md), [Fecundity](https://genetixbay.com/knowledge/glossary/fecundity.md)

## Read more

- [Temperature, humidity and pest population growth in cannabis: every major pest compared](https://genetixbay.com/knowledge/pests/temperature-humidity-and-pest-population-growth.md)

## Sources

1. Birch, L.C., 1948. The intrinsic rate of natural increase of an insect population. Journal of Animal Ecology 17:15-26. https://doi.org/10.2307/1605