Cockchafers

Host plants: Adult beetles feed on the foliage of broad-leaved trees and shrubs, often causing visible damage to fruit trees. The larvae, commonly known as white grubs, are polyphagous and feed on the roots of grasses, vegetables, strawberries, and young trees, posing a severe threat to nurseries and plantations.

Biology and lifecycle: The life cycle is typically 3 to 5 years, with the majority of this time spent in the soil as larvae. Adult beetles emerge in spring to feed and mate. Females lay batches of eggs in the soil. As the larvae grow, they move through the soil layers, feeding on roots and damaging the plant's capacity to uptake water and nutrients.

Damage and pest status: While adult beetles can cause defoliation, the subterranean larval stage is the most destructive. Larvae consume roots, leading to plant wilting, stunted growth, and eventual death. Severe infestations can devastate an entire field or orchard, causing significant economic losses.

Control measures: Management strategies include cultural and chemical interventions:

• Regular deep soil cultivation to physically damage and expose larvae to predators.
• Use of trap crops or intercropping with repellent plants.
• Chemical control through soil-incorporated insecticides at the time of planting.
• Biological control utilizing entomopathogenic fungi or nematodes to target soil-dwelling larvae.