Scarab beetle Exolontha serrulata

Systematic position: Exolontha serrulata belongs to the order Coleoptera and the family Scarabaeidae. This species is recognized as a significant soil-dwelling pest that poses a continuous threat to various agricultural and forestry crops during its developmental stages.

Host plants: This beetle is a polyphagous pest with a wide range of hosts. Its larvae feed primarily on the roots of vegetables, such as potatoes, as well as cereals, pasture grasses, and young saplings in tree nurseries, causing economic losses in both farm and forest sectors.

Biology and life cycle: The life cycle of Exolontha serrulata is primarily spent underground. Females lay eggs in moist, organic-rich soil. Upon hatching, the larvae undergo several instars over multiple years, feeding actively on plant root systems. Adult beetles are typically nocturnal and may cause minor damage to foliage, while the larvae are responsible for the primary agricultural damage.

Damage and harmfulness: The larvae cause damage by severing root systems or creating galleries within roots and tubers. This activity restricts nutrient and water uptake, resulting in stunted growth, yellowing of leaves, and frequently the death of the plant. High larval density can lead to patchy crop stands and total failure of sensitive plantings.

Control measures: Management of this pest requires an integrated approach to reduce population numbers:

• Deep tillage of soil during the pupation period to expose larvae to natural predators.
• Crop rotation to break the life cycle of the pest.
• Application of soil-incorporated insecticides at the time of planting for immediate protection.
• Use of biological control agents, such as entomopathogenic fungi or nematodes, to suppress larval survival in the soil.