Gooseberry Sawfly
Risk near you, next 48h
See whether your local forecast favours this disease right now.
When it strikes
Treat, then re-check in 5–7 days
Pick off the worst material, apply the organic option below, and look again after five to seven days. If the spread continued, escalate rather than repeating the same treatment.
Carried by insects
An insect moves it plant to plant, so controlling the carrier matters as much as treating the symptom. Check for the vector before assuming the plants infected each other directly.
Safe to compost
No pathogen carries over on this material, so it can go on an ordinary heap with the rest of the garden waste.
When and where to look
Scout the planting while temperatures hold between 12°C and 28°C.
Rule these out first
Same category, and at least one host crop in common — so they are genuinely confusable in the same part of the garden.
The signs that lead here
Full problem lists for these crops
About
Gooseberry sawfly (Nematus ribesii) can defoliate a gooseberry or currant bush completely in under a week. There are three generations a year, and the first is usually well advanced inside the bush before anyone notices anything from outside.
Symptoms
Feeding starts low in the centre of the bush, so the outside looks fine while the middle is stripped. Pale green caterpillars with black spots eat leaves down to the midribs. Defoliated bushes still fruit but the berries stay small and the plant is weakened.
Organic Treatment
Inspect the centre of the bush weekly from May — parting the branches and looking at the lower inner leaves catches the first generation while it is still confined to a few shoots. Pick the larvae off by hand or knock them onto a sheet.
Chemical Treatment
Pyrethrum or an approved contact insecticide gives control if applied to the inner and lower foliage where the larvae actually are. Spraying the outside of the bush achieves nothing.
Prevention
Prune to an open goblet so the centre is visible and reachable, and cultivate the soil under the bush in winter to expose overwintering cocoons. Keep checking after each generation — reinfestation within three weeks is normal.
Crops at risk
Related problems
Gooseberry Sawfly risk by location
Each location has a month-by-month profile computed from the weather archive: how many hours a year actually meet this disease’s thresholds.