Hairy scarab

Systematic position. The hairy scarab (Imatismus villosus) belongs to the order Coleoptera and the family Scarabaeidae. This species is a recognized pest in various agricultural regions, known for its distinct morphology and impact on plant reproductive structures during the spring and summer seasons.

Host crops and impact. This pest primarily targets grain crops, corn, sunflower, and various legumes. Adult beetles are characterized by their feeding habits on the generative organs of host plants. By destroying flowers and developing ovules, they directly contribute to significant yield losses, often affecting the quality of the final harvest by preventing successful seed formation.

Biology and life cycle. The life cycle of Imatismus villosus is largely subterranean. Adults overwinter deep in the soil profile. As spring temperatures rise, the beetles emerge to feed and mate. Eggs are deposited in the soil, where the larvae feed on decaying organic matter and occasionally on the root systems of crops, remaining largely hidden from traditional scouting methods until the adult emergence phase.

Nature of damage. The most critical damage occurs during the flowering stage of the crops. The beetles congregate on the inflorescences, consuming anthers, styles, and stigmas. This mechanical feeding prevents fertilization, resulting in poor grain set, thin ears, or empty heads. The damage is often most severe at the edges of fields near non-cultivated areas where the beetles congregate.

Control measures. Integrated pest management (IPM) is essential for controlling this beetle. Key strategies include deep tillage, which disrupts the overwintering sites of the adults and larvae, and crop rotation to break the pest's cycle. Chemical control using approved insecticides should be timed to match the mass emergence of the adults, targeting them before they cause irreversible damage to the reproductive stage of the crop.