author(s)
Mamane Sani Halilou, Abdou Hame Kadi Kadi, Moumouni Dan Mairo Adamou and Ali Doumma

abstract
This study investigates the influence of soil texture and natural powdered substances on the pupation of Noorda blitealis, a major defoliating pest of Moringa oleifera, an important leafy vegetable in the Sahel region. Laboratory experiments tested three soil types (sandy, clay-silty, and sandy-clay-silty) to assess their impact on cocoon formation, pupation, and adult emergence. Results showed that all soil textures equally supported successful development, while the absence of substrate significantly reduced cocooning and pupation, highlighting the importance of a physical medium for metamorphosis initiation. In a second phase, natural powders (neem seed kernel powder and wood ash) were mixed with sandy soil to evaluate their insecticidal potential. Neem powder showed strong disruptive effects: at 20% and 40% concentrations, it completely inhibited pupation and adult emergence, confirming its insect growth-regulating and toxic properties. In contrast, wood ash had little effect on cocoon formation but significantly reduced adult emergence at higher concentrations, suggesting interference with later developmental stages, possibly through physical or physiological stress. These findings emphasize the critical role of substrate presence in triggering pupation in N. blitealis, and demonstrate the potential of soil amendments with natural powders as eco-friendly pest management tools. Neem, in particular, emerges as a promising candidate for disrupting the insect’s life cycle through soil contact. The use of locally available substances like neem and ash aligns with the principles of Integrated Pest Management (IPM), offering sustainable alternatives to synthetic insecticides. However, further research is needed to assess long-term effects on soil ecosystems and to better understand the physiological mechanisms involved, especially regarding ash. This approach contributes to the development of agroecological strategies for controlling N. blitealis in Moringa oleifera-based systems, with direct implications for food security and environmental sustainability in Sahelian farming communities.