Orchid weevil

The orchid weevil (Diorymerellus lepagei) is a small but highly destructive beetle belonging to the Curculionidae family. It is recognized as a major pest of cultivated orchids, frequently causing significant economic losses in commercial nurseries and damage to private orchid collections worldwide.

This species primarily targets various orchid genera, including Cattleya, Dendrobium, and Phalaenopsis. The weevil is attracted to tender plant parts, such as developing flower spikes, buds, and young leaf tissue, which are essential for the plant's growth and reproduction.

The biology of Diorymerellus lepagei is characterized by a cryptic lifestyle. Adult weevils typically hide deep within the leaf sheaths or between the rhizome and pseudobulb during the day, emerging to feed at night. Females deposit eggs into the plant tissue, where larvae bore into the stems, causing internal structural damage as they mature.

Infestation symptoms are often identified by minute feeding punctures on the buds and leaves. These entry points frequently become entry sites for opportunistic fungal and bacterial pathogens, which cause the tissue to blacken and decay. Severe infestations can result in the complete abortion of flower spikes and the decline of the plant's vigor.

Effective management and control strategies involve integrated pest management practices.

• Implementing strict quarantine protocols for any new orchid specimens.
• Manual removal of visible adult weevils, particularly during late evening hours when they are most active.
• Application of systemic insecticides that are absorbed by the plant to combat larval stages inside the stems.
• Maintaining greenhouse hygiene by removing debris and sanitizing growing areas to minimize hiding spots.