author(s)
Esther Adhiambo Abonyo, George Otieno Ongámo, Gideon Nzioka Nyamasyo, Catherine Wanjiru Lukhoba, Gerphas Okuku Ogola, Midingoyi Soul-Kifouly, Hippolyte Affognon and Bruno P Le Ru

abstract
Sorghum and maize are important crops whose production is constrained by stem borers such as Busseola fusca. In Kenya, two distinct populations of Cotesia sesamiae, a parasitoid of B. fusca exist. The virulent highland biotype was released in the coastal region where the avirulent biotype existed. However, post release surveys were not done to assess for establishment. This survey was undertaken in release areas where 100 maize plants were inspected for infestation and ten plants dissected to recover stem borers in each farm. Results revealed that B. fusca was the most dominant pest (85.5%). Overall infestation was 19.17±2.48% and varied significantly among stem borer species (X²₂=16.86, p=0.00022) Overall parasitism was 10.78±4.34% and did not show significant variation from parasitoid pre-release rates (V=3, p>0.05). Cotesia sesamiae was recovered from C. partellus only suggesting that it was the avirulent biotype. The highland C. sesamiae did not establish in coastal Kenya.