Johnston's Truxalis

Johnston's Truxalis (Truxalis johnstoni) belongs to the family Acrididae within the order Orthoptera. This insect is primarily recognized as a specialized pest in arid and semi-arid regions of Africa, where it has evolved to thrive in open grassland and agricultural habitats.

The pest primarily targets cereal crops, including maize, sorghum, and millet, as well as various wild grasses. The insects consume foliage by feeding on the edges of the leaves and skeletonizing the tissues, which can result in significant leaf area loss during severe outbreaks.

The biology of this species is heavily influenced by moisture availability. The life cycle consists of egg, nymph, and adult stages. Females lay eggs in the soil, which remain in diapause until environmental conditions favor hatching. Nymphs pass through several instar stages, steadily increasing their feeding capacity.

Damage symptoms include irregular leaf margins and the presence of frass on the leaves. The economic impact is linked to the reduction of photosynthetic leaf area, which directly hinders plant development, affects kernel formation, and causes a measurable decline in total crop yield.

• Deep plowing to destroy egg pods.
• Effective weed control in and around fields.
• Monitoring pest density during early crop growth.
• Application of contact or systemic insecticides if thresholds are exceeded.

To effectively manage populations, integrated pest management (IPM) strategies are essential. Farmers should focus on preventive cultural practices to minimize initial infestations and use chemical control selectively to ensure that the pest populations remain below the economic injury level.