Adoretus bicolor

Adoretus bicolor is a notable beetle species belonging to the family Scarabaeidae, order Coleoptera. This beetle is recognized as a significant pest in various agricultural and horticultural environments, primarily due to the feeding habits of the adult stage on the foliage of host plants.

The host range of this pest is quite broad, impacting various crops including grapevines, pome fruits (such as apples and pears), stone fruits, and ornamental shrubs. Due to their tendency to feed in groups, these beetles can rapidly deplete the leaf surface of a healthy plant.

The biological cycle of Adoretus bicolor involves a soil-dwelling larval stage and an active aerial adult stage. Eggs are laid in moist soil rich in organic matter. After hatching, the larvae develop underground, often feeding on organic debris or roots, before emerging as adults that strictly follow a nocturnal activity pattern.

The characteristic damage caused by the adults is known as skeletonizing. They consume the interveinal tissues of the leaves while leaving the vascular veins intact, resulting in a lace-like appearance of the foliage. Severe infestations can cause complete defoliation, leading to plant stress, reduced vigor, and decreased yield potential.

Management and control strategies are essential for minimizing economic loss.

• Deployment of light traps at night to attract and kill adult beetles.
• Soil cultivation during the pupation stage to disrupt the life cycle of the larvae.
• Application of targeted insecticides during peak adult activity periods.
• Maintaining healthy plant nutrition to help the vegetation recover from foliage loss.