Psilopholis grandis

Psilopholis grandis is a significant soil-dwelling pest belonging to the order Coleoptera and the family Scarabaeidae. This species is recognized as a major threat to agricultural productivity in regions where its larvae proliferate, causing extensive damage to the root systems of various plants.

The host range of Psilopholis grandis is broad, affecting both perennial plantations such as tea and rubber trees, and various herbaceous crops. Young seedlings and nursery plants are particularly vulnerable, often suffering total destruction within a short period due to the feeding activity of the larvae.

The biology and lifecycle of the pest involve a lengthy soil-dwelling larval stage that can span several years. During this time, the larvae undergo multiple molts, consuming vast amounts of root tissue. The adults emerge to feed on foliage, completing a cycle that ensures the persistence of the population in the soil.

The primary symptom of infestation is the sudden wilting of host plants. By consuming the primary and secondary roots, the larvae disrupt water and nutrient uptake, leading to irreversible plant stress, poor growth, and eventual death of the affected crops in the field or greenhouse.

Management strategies for this pest include:

• Cultural control: Deep soil tillage to expose larvae to natural predators and environmental stressors.
• Chemical control: Precise application of systemic or contact insecticides into the soil profile.
• Biological control: Implementation of microbial pesticides utilizing insect-pathogenic fungi.
• Integrated monitoring: Tracking adult beetle emergence to time control measures appropriately.