Assessment of Insect Infestation of Senegalia macrostachya (Reichenb. ex DC.) Kyal. & Boatwr. Seeds at Pod Harvest in the Northern and Southern Sudanian Agroclimatic Zones of Burkina Faso

Abstract

Aims: To assess the effect of insect pest infestation on the quality of S. macrostachya seeds at pod harvest in the North- and South-Sudanian agroclimatic zones of Burkina Faso. Study Design: Seeds of S. macrostachya were collected and examined, and the insects that emerged were identified. Place and Duration of Study: The study was conducted at the Laboratory of Fundamental and Applied Entomology, Joseph KI-ZERBO University, between December 2025 and June 2026. Methodology: Three batches of 2,000 S. macrostachya pods were collected from Bama and Gonsé. At each site, each batch was sampled from 20 different shrubs. The samples were transported to the laboratory where they were threshed and 1,000 seeds from each batch were examined and monitored under ambient laboratory conditions for 90 days. Results: At harvest, 57.46% and 49% of the seeds were perforated in Bama and Gonsé, respectively. Bruchidius silaceus was the predominant insect pest of S. macrostachya seeds in January in both non-perforated and perforated seeds collected at Bama, representing 74.31% and 66% of the specimens collected, respectively. In Gonsé, no B. silaceus individuals emerged from unperforated seeds in January, whereas the species accounted for 75.93% of the insects emerging from the perforated seeds. C. furcatus first appeared in the seed stocks in February. Apomecyna sp., which was collected with the pods in Bama, was not recorded in Gonsé. Eupelmus sp. was the most abundant parasitoid species. Conclusion: S. macrostachya pods should be harvested immediately after reaching physiological maturity to minimise seed perforations caused by the emergence of insect pests.