Raspberry beetle: how to recognise and treat it

Pest

Symptoms

Ripe berries with greyish-brown, dried-up patches at the stalk end.
A brownish-white grub up to 8 mm long inside the fruit.
Pale brown beetles about 4 mm long on the flowers from May; mainly a problem on summer-fruiting raspberries, while autumn berries ripening after late August are rarely damaged.

Tolerate light damage — often only a small part of the crop is affected, and later berries suffer less.
In spring and early summer shake the canes over a sheet or tray and drop the fallen beetles into soapy water; pick off any beetles you see.
Hang a host-scent water trap or white sticky traps to catch adult beetles; sticky traps also catch other insects.
Where damage is heavy, pyrethrins or spinosad at the pink-fruit stage and again two weeks later; follow the label.

No synthetic insecticide is advised for garden use; if spraying, use the pyrethrins or spinosad timing above and never spray open flowers, to protect bees and other pollinators.

Reference information, not a guarantee. Read and follow the label of any product: dose, safety and the days to wait before harvest.

Lightly dig over the soil around the canes in autumn and winter, where the beetles overwinter, so birds and ground beetles can reach them.
Encourage birds, hedgehogs and ground beetles in the garden.
Where the beetle is a regular problem, favour autumn-fruiting raspberries, whose later crop mostly escapes damage.

Figures checked against these sources.