The intensive use of synthetic pesticides in cowpea storage has led to the development of resistance by Callosobruchus maculatus and subsequent degradation of the grains quality. In an attempt to circumvent these constraints, we investigated the susceptibility of C. maculatus to 2, 3-Dichlorovinyl dimethyl phosphate (DDVP) and Lippia adoensis essential oil (EO) and then assessed the variations in the proportions of nutritional values of treated grains 150 days after storage. The survival rate was recorded after 5 generations. The resistance index and biochemical parameters of grains were determined according to previously described techniques. The survival rate (SR) and resistance index (RI50 and RI95) significantly increased in DDVP treatments (r=0.889; p=0.018) proportionally with damage whereas in EO treatments, those values remained lower although showed a slight but not significant variations (p=0.0764) throughout generations. DDVP stored grains yielded higher crude protein values, but lower carbohydrates, tannins, phenolics and minerals compared to EO. Eighteen amino acids were detected in EO treated grains and 14 in DDVP which was devoid of albumin and prolamin. EO could therefore represent a safe alternative bio-pesticide to cope with the insect resistance and enhance the nutritional qualities of stored cowpea seeds.