Popillia chlorion

Systematic position. Popillia chlorion is a member of the order Coleoptera, belonging to the family Scarabaeidae, specifically the subfamily Rutelinae. This species is closely related to other notorious scarab beetles known for their invasive nature and potential to damage various horticultural and agricultural crops, necessitating proper monitoring and control measures.

Host plants. This pest acts as a polyphage, demonstrating a wide range of host plants. It is known to attack various fruit trees, shrubs, and ornamental plants. The adults specifically target foliage, buds, and flowers, while the larval stages are soil-dwellers that interact with the root systems of various plant species, potentially causing widespread damage to nurseries and commercial orchards.

Biology and life cycle. The species undergoes a complete life cycle, consisting of eggs, larvae, pupae, and adults. Adult beetles emerge during the summer months, feeding on aerial plant parts. Females lay eggs in the soil, and the resulting larvae feed on organic matter and plant roots throughout their development. The life cycle typically spans one or more years depending on environmental conditions, with overwintering occurring in the larval stage underground.

Damage patterns and economic impact. The primary injury caused by adults includes leaf skeletonization and the destruction of flowers, which significantly impacts the aesthetic and commercial value of the crops. The larvae cause indirect damage by feeding on root systems, which can lead to stunted plant growth, reduced water and nutrient uptake, and in severe cases, the death of younger plants, causing substantial economic losses.

Control measures. Effective management requires an integrated approach to reduce population levels below the economic injury threshold.

• Cultural control: Regular soil cultivation to disturb larval habitats and expose them to natural predators.
• Biological control: Utilization of entomopathogenic fungi or nematodes to target soil-dwelling larvae.
• Chemical control: Application of authorized insecticides during the adult emergence peak.
• Monitoring: Use of light and pheromone traps to time interventions accurately.