Pea moth

Pea moth caterpillars feed inside pea pods but the damage is often only spotted at harvest. Consequently, the pods need to be shelled with care to avoid contamination.

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Pea moth (<EM>Cydia nigricana</EM>)
Pea moth (Cydia nigricana)

Quick facts

Common name Pea moth
Latin name Cydia nigricana
Plants affected Garden peas
Main symptoms Small creamy white caterpillars eat the peas inside the pods
Caused by Caterpillars of a small moth
Timing Late June-August

What is pea moth?

Pea moth is a small (15mm wingspan), grey-brown moth whose larvae (caterpillars) feed in the pods of garden peas.


  • When pea pods are opened for shelling, one or more creamy white caterpillars, up to 14 mm long, with dark dots on the body may be found eating into the peas
  • There are piles of caterpillar excrement (frass) near the damaged peas


If pea moth has been a problem in previous years consider control options before sowing peas. When choosing control options you can minimise harm to non-target animals by using the methods in the non-pesticide section below. Pesticide treatments are likely to kill natural enemies and can be avoided here by use of an insect-proof mesh. 


  • Peas can be grown under horticultural fleece, insect-proof mesh, to prevent female moths laying eggs on the plants. Peas are self-pollinating and so excluding bees and other pollinators with fleece will not affect the crop
  • Quick-maturing cultivars that are sown early or late and which flower outside of the egg laying period of the moth (June and July) should remain un-infested. Similarly mange-tout types of pea, where the pods are eaten before the seeds develop, should not be affected


The RHS recommends that you don't use pesticides. Most pesticides (including organic types) reduce biodiversity, including natural enemies, impact soil health and have wider adverse environmental effects.
Pesticide treatments are likely to kill natural enemies and so reduce the likelihood of natural control and can lead to resurgence of the target animal.

The pesticides listed are legally available in the UK. This information is provided to avoid misuse of legal products and the use of unauthorised and untested products, which potentially has more serious consequences for the environment and wildlife than when products are used legally.
Always follow the instructions on the products. For edible plants, make sure the food plant is listed on the label and follow instructions on maximum number of applications, spray interval and harvest interval.
Homemade products are not recommended as they are unregulated and usually untested.
Be aware that products such as Neem oil are not registered for use in the UK and we cannot advise on their use.

Plants in flower must not be sprayed due to the danger to bees and other pollinating insects.

  • Pesticide control can be avoided by using insect-proof mesh. Whilst there are some insecticides labelled for use on peas, adult pea moth is active when peas are in flower and plants in flower should not be sprayed due to the danger to pollinating insects.
  • Further information about the use of pesticides available can be found on the pesticides for gardeners leaflet.

Inclusion of a pesticide product does not indicate a recommendation or endorsement by RHS Gardening Advice. It is a list of products currently available to the home gardener.


Pesticides for gardeners (pdf document)


Adult pea moths emerge in June-July, when the females seek out pea plants on which they lay their eggs. They are attracted to pea plants that are in flower.

After hatching, the caterpillars bore into the developing pea pods and begin feeding on the seeds. When fully fed in mid- to late summer, the caterpillars leave the pods and go into the soil to pupate.

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