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

Sawfly are small winged insects, related to bees, wasps and ants. Their caterpillar-like larvae feed on the leaves or fruits of certain plants, including apples, gooseberries and Solomen’s seal.

• Defoliation of the bushes can be caused by the caterpillar-like larvae of one of three species of sawfly
• Larvae of the common gooseberry sawfly (Euura ribesii) are up to 20mm long, pale green, with many black spots, and black heads. The adults are winged insects; females are 5-7mm long and are yellow with black heads and black markings on the thorax; males are similar but more extensively marked with black, including the upper surface of the abdomen
• Larvae of the pale spotted gooseberry sawfly (E. leucotrochus) are slightly smaller than those of the common gooseberry sawfly and have pale green heads. It has one generation a year with larvae present in May and June. The adult is similar in appearance to the pale spotted gooseberry sawfly but are usually brown in colour 
• The small gooseberry sawfly (ristiphora appendiculata) can have up to four generations of pale green larvae from late April onwards. The adult about 5mm long is black with pale yellow leggs. 
• The larvae of some moths may also eat the foliage of gooseberries and currants
• Plants will usually survive complete defoliation, however this may reduce yield

Check susceptible plants frequently from spring onwards so action can be taken before a damaging population has developed. When choosing management options you can minimise harm to non-target animals by starting with the methods in the non-pesticide control section and avoiding pesticides. Within pesticides the shorter persistence products (that are usually certified for organic growing) are likely to be less damaging to non-target wildlife than those with longer persistence and/or systemic action. Pesticide treatments are likely to kill natural enemies and are only likely to be successful if the entire plant can be reached.

Non-pesticide control

• Where possible tolerate populations of sawfly, complete defoliation rarely kills the plants although cropping may be affected
• Encourage predators and other natural enemies of sawfly in the garden, such as birds and ground beetles.
• Check plants regularly from April for the presence of larvae and remove by hand where practical
• A biological control (pathogenic nematode), sold as Fruit and Vegetable Protection, can be watered onto infested plants. The nematodes enter the bodies of the sawfly larvae and infect them with a bacterial disease. This nematode is available from some garden centres or via mail order. The nematode should be applied during cool damp weather

• If numbers of larvae are too high for hand picking, control may be achieved by spraying with pesticides. Spraying at dusk is likely to give the best results
• Organic contact insecticides containing natural pyrethrum (e.g. Bug Clear Ultra 2, Neudorff Bug Free Bug and Larvae Killer). Several applications of this short persistence products may be necessary to give good control
• More persistent contact-action insecticides include the synthetic pyrethroids lambda-cyhalothrin (e.g. Westland Resolva Bug Killer), deltamethrin (e.g. Provanto Ultimate Fruit & Vegetable Bug Killer, Provanto Sprayday Greenfly Killer) and cypermethrin (e.g. Py Bug Killer)

Downloads

Pesticides for gardeners (pdf document outlining pesticides available to home gardeners)Non-pesticide control

Biological control suppliers (pdf document)

• The common gooseberry sawfly is the most frequently found of the gooseberry sawflies. It can have three generations a year, with the larvae active in late April to June, July, and August to September
• The female sawflies lay eggs on the underside of leaves, low down in the centre of the bush, so the young larvae go unnoticed until they have eaten their way upwards and outwards, devouring the leaves as they go
• Defoliated plants are weakened and may produce a poor crop the following year
• When the larvae are fully fed, they go into the soil, where they spin silk cocoons and pupate
• The pale spotted gooseberry sawfly only has one generation a year with larvae present in May and June
• The small gooseberry sawfly has up to four generations a year with larvae present from late April