Potato stalk borer

The potato stalk borer (Trichobaris trinotata) is a beetle belonging to the family Curculionidae (order Coleoptera). It is a specialized pest that targets solanaceous plants, causing severe internal damage to the stems of host crops, which often leads to significant agricultural losses.

This pest primarily attacks potatoes, tomatoes, eggplants, and various wild solanaceous weeds such as nightshade and jimsonweed. The infestation is particularly damaging because the feeding occurs inside the plant tissue, making early detection and control challenging for farmers and agronomists.

Regarding its biology, the beetle overwinters as an adult in debris or soil. In the spring, they emerge to feed on foliage before mating. Females then deposit eggs into the stems or leaf petioles. Upon hatching, the larvae tunnel into the core of the stem, where they feed throughout their development, effectively hollowing out the plant stalk.

Damage symptoms include the wilting and lodging of stems, leading to stunted plant growth and reduced tuber or fruit size. Because the larvae are protected inside the stem, the structural integrity of the plant is compromised, and the transport of nutrients from the foliage to the roots or fruits is severely disrupted.

Effective management strategies require a combination of cultural and chemical controls. Key practices include:

• removing and destroying infested plants to prevent population buildup;
• maintaining a crop rotation that excludes solanaceous hosts for several seasons;
• sanitation of field borders to eliminate wild host plants;
• application of systemic insecticides when adults are observed on the plants before egg-laying begins.