author(s)
Matseu Sakou Geraldine Noël, Kouninki Habiba, Ngatanko Iliassa and Nukenine Nchiwan Elias

abstract
The effect of mixed powders of Vepris heterophylla and Syzygium aromaticum on the developing stages of Callosobruchus maculatus was investigated. Quantities of 0.25, 0.50, 0.75 and 1.00 g of mixed plant powders were measured: PA= 1/2VS +1/2VL, PB= 1/2VS +1/2SA, PC=1/2VL + 1/2SA and PD=1/3VS+1/3VL+1/3SA (VS= Vepris stem bark, VL= Vepris leaves, SA= Syzygium aromaticum and P= Powder). They were applied to 100 g of cowpea seeds, followed by infestation with ten pairs of 48 hours old Callosobruchus maculatus. The highest mortality (100%) was obtained with 1.00 g of mixtures PD and PC while the least (82.5%) was recorded with 0.25 g of the mixture PA. The increase in the doses led to the decrease in the number of eggs laid with the highest mean percentage of oviposition deterrence been 98.44% at 1 g/100 g due to powder PB and the least 93.43% with 0.25 g due to powder PA. The mixtures reduced adult emergence of F₁ from 90.83% (powder PB) to 82.5% (powder PA). It also reduced the percentage of attack from 98% (control) to 0% for powder PB which was the best. The rate of germination increased with the quantities of powder applied.