Optimization of insecticidal potency of composites of aqueous, acetone, and ethanol extracts of Piper guineense seed on Callosobruchus maculatus by the simplex-lattice mixture experimental design

The objective of this study was to investigate the effect of composites of extracts of Piper guineense seed on Callosobruchus maculatus using the mixture experimental design of the response surface methodology (RSM).Callosobruchus maculatus damages stored legumes and grains resulting in huge agronomic and economic losses. Synthetic chemical insecticides is currently in useto check the wastage despite their known toxicity to man and the environment. Efforts to find alternatives to chemical synthetic insecticides has spotted Piper guineenseas a promising alternative candidate but less work has been done on its preparation and formulation for optimum activity. Fresh Piper guineenseberry was harvested from Essien Udim Local Government Area, of Akwa Ibom State, it was dried in the sun to moisture content of about 14% and ground to pass through 100 mesh sieve. The ground seed was extracted with ethanol and concentrated to obtain a slurry. Single blends of aqueous, ethanolic, acetone extracts of Piper guineense seed showed increasing insecticidal potency on the testinsect than binary blends.The model of dead insect was significant (R2=0.9931, Mean=68.69), bean damage was significant (R2=09786, Mean 63.46). Optimization analysis of experimental data revealed that 0.09, 0.437, 0.473 proportions of aqueous, ethanolic, and acetone extracts of Piper guineense seed respectively produced 95% and 31% dead insects and bean damage respectively at a desirability level of 76.80%.Result of the study shows that composites extracts of Piper guineense seeds could be a useful controller of stored maize.