Geum sawflies

The caterpillar like larval stage of two species of sawfly can feed on Geum in spring and summer.

Geum sawfly (<EM>Claremontia waldheimii</EM>) on <EM>Geum</EM>
Geum sawfly (Claremontia waldheimii) on Geum

Quick facts

Common name Geum sawflies
Latin names Claremontia waldheimii and Monophadnoides rubi
Plants affected Geum species
Main symptoms The foliage is eaten by pale green caterpillar-like larvae
Caused by Larvae of sawflies
Timing May-July

What are Geum sawflies?

Sawflies are a group of insects suborder (Symphyta) of the Hymenoptera (bees, ants and wasps). There are about 500 species of

sawfly in Britain. They have caterpillar like larvae that feed on plant material and are named after the saw like egg laying organ used by females to lay eggs in plant material. Adults can come in a range of colours many are black, green orange or striped yellow and black. Most are small (< 1cm) but some species such as the Birch sawfly (Cimbex femoratus) can be over 2 cm long. Several species can be found in gardens and are part of the biodiversity a healthy garden will support. More information can be found at The Sawflies of Britain and Ireland webpages

There are two species of geum sawflies they have pale green larva, with small white spines. The larvae reach 15 mm in length that eat the leaves of Geum plants in the spring and summer. The adult insects are about 6 mm long and mainly black.


Geum sawfly larvae initially feed concealed between the folds of unexpanded leaves. As they grow they consume large irregular holes and damage can occur very quickly and defoliation can be extensive. Signs of geum sawflies include;

  • Pale green caterpillar-like larvae with small whitish spikes up to 15 mm long
  • Leaves can be reduced to a network of the larger leaf veins, affecting the appearance and vigour of  plants
  • Affected plant often recover with no long term effects


Check geums frequently from spring onwards so action can be taken before a damaging population has developed. 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 are only likely to be successful if the entire plant can be reached.

Geums can cope with low numbers of larvae and damage can usually be tolerated and the presence of these insects treated as part of the biodiversity a healthy garden supports.


  • Where possible treat this sawfly as part of the biodiversity a healthy garden can support, plants usually recover from defoliation
  • Encourage predators and other natural enemies of sawfly in the garden, such as birds and ground beetles.
  • Check plants regularly in May and June for the presence of larvae and remove by hand where practical


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.

Where you cannot tolerate sawflies, manage them using the information above as your first course of action.
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.

If you do decide to use pesticides, the shorter persistence products (that are usually certified for organic growing) are likely to be less damaging to non-target wildlife.
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.
  • If numbers of larvae are too high for hand picking, control may be achieved by spraying with pesticides. Spraying at dusk is likely to be more effective
  • Organic contact insecticides containing natural pyrethrum (e.g. Bug Clear Ultra 2, Neudorff Bug Free Bug and Larvae Killer) have a largely physical mode of action. These are broad spectrum so will kill a wide range of insects. Several applications of these short persistence products may be necessary to give good control. Plant oil and fatty acid products are less likely to affect larger insects such as ladybird adults
  • Further information about the use of pesticides available for management of sawfly is available 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 outlining pesticides available to home gardeners)


The larvae of geum sawflies (Claremontia waldheimii and Monophadnoides rubi) feed on the foliage of cultivated and wild Geum species.

There is one generation a year with larvae active during late May and June. They initially feed concealed between the folds of unexpanded leaves. The larvae of both species are pale green with rows of bifurcated (divided into two) whitish spines on the dorsal surface. When fully grown in late June they go into the soil where they spin silk cocoons, where they overwinter. The adults are 5-6 mm in length, black in colour and emerge between late April and early June.

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