Black-spotted weevil

Taxonomic position: Cholus nigromaculatus belongs to the order Coleoptera and the family Curculionidae. This weevil species is recognized as a significant agricultural pest in tropical and subtropical regions, where it poses a continuous threat to the stability and productivity of various crops.

Host crops: This pest is particularly well-known for its damaging impact on pineapple plantations (Ananas comosus). While it shows a strong preference for specific bromeliads, it can also affect other related plants, causing severe economic losses by directly attacking the stems and fruit tissues of the host.

Biology and life cycle: The insect undergoes a complete metamorphosis. Adult females lay eggs into the plant tissues. Upon hatching, the larvae burrow into the stem or fruit, creating extensive tunnels. This internal feeding pattern is the most critical stage of its life cycle, as it protects the larvae from external environmental factors and many conventional pesticide applications.

Damage and pest status: The damage caused by Cholus nigromaculatus is significant. Larval tunneling disrupts the vascular system, resulting in stunted growth, necrosis of tissues, and premature fruit decay. Secondary infections often take hold at the injury sites, accelerating the decline of the plant and leading to substantial yield losses in affected fields.

Control measures: Management of Cholus nigromaculatus requires an Integrated Pest Management (IPM) approach to be effective. Key tactics include:

• Strict quarantine and inspection of planting material to prevent pest spread.
• Field monitoring using visual inspections and trapping techniques to detect early infestations.
• Sanitation practices, including the rapid removal and destruction of infested plant parts to reduce population pressure.
• Strategic application of systemic insecticides during critical windows of adult activity.
• Crop rotation or intercropping strategies where applicable to disrupt the life cycle of the pest.