Summer chafer

The Summer chafer (Amphimallon aestivus) is a beetle species belonging to the order Coleoptera and the family Scarabaeidae. This insect is widely recognized as a significant pest in agricultural fields, pastures, and forestry nurseries, particularly due to the subterranean feeding habits of its larval stage.

The primary damage is caused by the larvae, commonly known as grubs. These larvae dwell in the soil for several years, consuming the roots of various plants. This feeding activity disrupts the plant's ability to uptake water and nutrients, leading to stunted growth, wilting, and, in severe cases, the complete death of the host.

The life cycle of Amphimallon aestivus typically spans several years. Female beetles deposit eggs into the soil, and after hatching, the larvae pass through three distinct instars. They migrate vertically within the soil profile in response to moisture and temperature fluctuations, often staying deeper during winter and rising closer to the root zone in spring.

In terms of agricultural impact, infestations can result in significant economic loss, particularly in newly established lawns, nursery crops, and cereal fields. Because the grubs remain hidden, the damage is often identified only after the plants show clear signs of decline or when patches of vegetation begin to turn brown and die.

Management practices for controlling the summer chafer include:

• Mechanical soil cultivation to expose larvae to natural predators.
• Targeted soil application of insecticides during the early larval development stage.
• Incorporation of biological control agents such as entomopathogenic nematodes.
• Maintaining healthy plant vigor through balanced fertilization and irrigation.