Black sugarcane beetle

Systematic position: Heteronychus licas is a member of the order Coleoptera and the family Scarabaeidae. This species is recognized as a significant soil-borne pest in tropical agricultural ecosystems, causing substantial economic losses in various grain and industrial crop productions.

Target crops: The primary host is sugarcane, although the pest is also known to infest maize, rice, sorghum, and various grass species. The beetle poses the greatest threat to young seedlings, as it attacks the plant base just below the soil surface, preventing proper establishment of the crop.

Biology and lifecycle: The lifecycle follows a complete metamorphosis: egg, larva, pupa, and adult. The adults are robust, shiny black beetles that are nocturnal. The larval stage consists of C-shaped grubs that dwell in the soil, feeding on roots and organic matter, which makes them protected from many contact insecticides.

Type of damage and severity: Adults cause the most severe damage by boring into the basal part of the stem. This destruction of the vascular tissue leads to the classic symptom known as "dead heart," where the central leaf dies while the outer leaves remain temporarily green, eventually leading to stunted development or complete plant death.

Control measures: Integrated Pest Management (IPM) is essential for controlling Heteronychus licas. Key strategies include:

• Deep tillage prior to planting to expose larvae to natural predators and desiccation.
• Application of granular insecticides into the planting furrow during sowing.
• Maintaining field hygiene to reduce the presence of organic debris that attracts ovipositing females.

Monitoring population dynamics through the use of light traps is recommended to determine the optimal timing for intervention and to minimize the usage of chemical agents.