# Holocyclic and anholocyclic

> Aphid life cycles with (holocyclic) or without (anholocyclic) a yearly sexual generation that lays overwintering eggs.

- Canonical: https://genetixbay.com/knowledge/glossary/holocyclic.html
- Also written: holocyclic, anholocyclic, holocycle, anholocycle
- 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"

A holocyclic [aphid](https://genetixbay.com/knowledge/glossary/aphid.md) has one sexual generation a year, usually in autumn, in which males and egg-laying females mate and lay eggs that overwinter; the rest of the year females reproduce by [parthenogenesis](https://genetixbay.com/knowledge/glossary/parthenogenesis.md). An anholocyclic aphid skips the sexual stage entirely and reproduces asexually all year. UC [IPM](https://genetixbay.com/knowledge/glossary/ipm.md) describes both patterns among pest aphids.

## In practice

Indoors, the distinction matters for two reasons. Anholocyclic populations, such as [rice root aphid](https://genetixbay.com/knowledge/glossary/root-aphid.md) in cannabis rooms, never pause. Holocyclic species such as the [cannabis aphid](https://genetixbay.com/knowledge/glossary/cannabis-aphid.md) can produce sexual forms and eggs after the flip to short days, so a room that seems clean can carry overwintering eggs into the next run.

## Don't confuse with

- **Parthenogenesis**: the asexual reproduction both cycles use most of the year.
- **Diapause**: dormancy; overwintering aphid eggs are in [diapause](https://genetixbay.com/knowledge/glossary/diapause.md).

## Related terms

[Parthenogenesis](https://genetixbay.com/knowledge/glossary/parthenogenesis.md), [Aphid](https://genetixbay.com/knowledge/glossary/aphid.md), [Alate](https://genetixbay.com/knowledge/glossary/alate.md)

## Read more

- [Aphids on cannabis: species, life tables, population growth and IPM](https://genetixbay.com/knowledge/pests/aphids.md)
- [Cannabis aphid (Phorodon cannabis): ID, life table, overwintering and control](https://genetixbay.com/knowledge/pests/cannabis-aphid.md)
- [Root aphids (rice root aphid) on indoor cannabis: ID, life cycle in numbers and IPM](https://genetixbay.com/knowledge/pests/root-aphids.md)

## Sources

1. UC IPM. Pest Notes: Aphids (Publication 7404). https://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html