Adult beetles of the Garden Chafer (Phyllopertha horticola) emerge in May/June and mate. Females burrow into the ground to lay their eggs. Eggs hatch about 4 weeks later forming characteristic "C" shaped grubs – staying close to the soil surface until early October after which they move deeper over-winter. They pupate the following April. Chafer grubs cause damage to turf by feeding on roots and by predators (rooks, crows etc.) excavating the grubs.
Affected turf may have all roots severed. Predators may tear at the turf removing divots to expose the grubs causing further damage.