# Aphid

> Small soft-bodied sap-sucking insects of the family Aphididae that cluster on stems and leaf undersides, excrete sticky honeydew and multiply rapidly by live birth.

- Canonical: https://genetixbay.com/knowledge/glossary/aphid.html
- Also written: aphids, greenfly, blackfly, plant lice, green peach aphid, Myzus persicae
- 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"

Aphids are small, soft-bodied insects of the family Aphididae, about 1-3 mm long, that feed on [phloem sap](https://genetixbay.com/knowledge/glossary/phloem.md) through a needle-like stylet. Most have two tube-like cornicles at the rear. Indoors, females give birth to live young without mating, so a colony can double in days. Several species use cannabis, including the [cannabis aphid](https://genetixbay.com/knowledge/glossary/cannabis-aphid.md) (*Phorodon cannabis*) and the generalist green peach aphid (*Myzus persicae*).

## In practice

Signs are colonies on leaf undersides and stems, white cast skins, sticky [honeydew](https://genetixbay.com/knowledge/glossary/honeydew.md), and the black [sooty mould](https://genetixbay.com/knowledge/glossary/sooty-mould.md) that grows on it. Ants farming honeydew are a strong clue outdoors. Heavy feeding curls and yellows leaves, and some aphids carry [plant viruses](https://genetixbay.com/knowledge/glossary/plant-virus.md). Standard tools are [parasitic wasps](https://genetixbay.com/knowledge/glossary/aphidius.md) such as *Aphidius colemani*, predators such as lacewing larvae and ladybirds, and soft contact sprays such as [insecticidal soap](https://genetixbay.com/knowledge/glossary/insecticidal-soap.md) in veg only. Honeydew and cast skins on buds are a quality problem, so act early. Check what is registered for cannabis locally.

## Don't confuse with

- **Whitefly nymphs**: flat, scale-like and fixed in place on the leaf underside.
- **Root aphid**: lives on roots, rarely seen on foliage until late.
- **Mealybugs**: covered in white waxy fluff.

## Related terms

[Cannabis aphid](https://genetixbay.com/knowledge/glossary/cannabis-aphid.md), [Root aphid](https://genetixbay.com/knowledge/glossary/root-aphid.md), [Aphidius](https://genetixbay.com/knowledge/glossary/aphidius.md), [Ladybird](https://genetixbay.com/knowledge/glossary/ladybird.md), [Lacewing](https://genetixbay.com/knowledge/glossary/lacewing.md), [Insecticidal soap](https://genetixbay.com/knowledge/glossary/insecticidal-soap.md)

## Read more

- [Aphids on cannabis: species, life tables, population growth and IPM](https://genetixbay.com/knowledge/pests/aphids.md)

## Sources

1. UC IPM. Pest Notes: Aphids (Publication 7404). https://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html
2. UConn IPM. Biological Control of Aphids. https://ipm.cahnr.uconn.edu/ipm-biological-control-of-aphids/