Pest to manage
Cockchafer
Melolontha melolontha
Role in the garden
Adults grazing on tree leaves; larvae (white grubs) gnawing crop roots over a life cycle of 3 to 4 years (INRAE, Ephytia).
How to attract / manage it
Ground beetles, beneficial nematodes, rotation, soil worked in autumn.
Practical guide
Where to find them
Meadows, vegetable garden (white grubs in the soil), fruit trees (adults grazing on the leaves).
Prevention
Work the soil in autumn to expose the larvae to birds. Encourage hedgehogs and insectivorous birds.
Early signs
Plants suddenly wilting for no apparent reason; C-shaped white grubs visible when working the soil.
Action / control
Hand-picking of the larvae when digging. Application of Heterorhabditis bacteriophora nematodes in moist soil, between 12 and 20 °C (RHS).
Sources
- INRAE, Ephytia : Pomme de terre, Melolontha melolontha (hanneton commun)
- RHS (Royal Horticultural Society) : Chafer grubs in lawns (rhs.org.uk/biodiversity/chafer-grubs-in-lawns)