Rhopaea subnitida

Systematic position. The insect Rhopaea subnitida belongs to the order Coleoptera and the family Scarabaeidae. It is a member of the Melolonthinae subfamily, commonly referred to as white grubs. These beetles are characterized by their subterranean larval stage, which is responsible for significant economic losses in various types of vegetation.

Host plants. The larvae of this species are highly polyphagous, feeding on the root systems of various cereals, grasses, and vegetable crops. They also pose a serious threat to the establishment of young tree seedlings in forest plantations and orchards. Their ability to switch between different types of food sources makes them persistent pests in diverse agricultural environments.

Biology and life cycle. The development cycle of Rhopaea subnitida is entirely dependent on the soil environment. Larvae spend several years underground, moving through different larval instars while feeding on organic matter and living roots. As environmental temperatures fluctuate, they perform vertical migrations within the soil profile to find optimal conditions for survival and growth.

Damage and pest impact. The primary economic impact occurs when larvae sever the roots of the host plants, preventing the uptake of water and essential nutrients. This results in the rapid wilting and yellowing of the foliage, followed by the death of the entire plant. In fields, heavy infestations often appear as circular patches of dead or stunted crops, which can be easily pulled from the ground due to the lack of a stable root system.

Protection measures. Effective management requires an integrated pest management (IPM) approach. Cultural practices such as crop rotation and deep autumn plowing are essential to disrupt the larval environment and increase exposure to natural predators. Chemical control involves the application of granular soil insecticides, while biological control options often include the use of entomopathogenic fungi or nematodes to manage populations sustainably.