Cotton stem weevil

Eutinobothrus is a genus of weevils belonging to the Curculionidae family. Within this genus, Eutinobothrus brasiliensis is specifically identified as a major pest that impacts cotton agriculture, particularly in South American countries.

Classified under the order Coleoptera, this insect is biologically specialized to inhabit and feed on the woody tissues of plant stems. This specialization makes it a significant challenge for crop management programs, as the pest remains hidden within the plant host for most of its life cycle.

The primary host crop is cotton (Gossypium). The damage is mainly caused by the larvae, which bore galleries into the stems. This internal feeding disrupts the plant's vascular system, leading to stunted growth, wilting, and in severe cases, the lodging or death of the affected plants.

The life cycle involves complete metamorphosis, where eggs are laid in the plant tissue. Larvae develop through several instars while burrowing inside the stem, eventually pupating in a specially prepared chamber before emerging as adults. Understanding these stages is critical for determining the timing of control efforts.

Effective control measures require an integrated approach. Farmers are advised to perform deep plowing after harvest to destroy pupae, ensure proper crop rotation to break the pest's cycle, and apply systemic insecticides if economic thresholds are reached during the early stages of plant development.