A Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Master’s in Life Sciences of the Nelson Mandela African Institution of Science and TechnologyA randomized complete block design was used to set up field and storage experiments to evaluate the effects of pesticidal plants on common bean pollinators’ attraction in the field and Callosobruchus maculatus control in cowpea storage. Pesticidal plants Hyptis suaveolens, Osimum suave, Dysphania ambrosioides and Sphaeranthus suaveolens were planted as field margin plants (FMPs) in a plot size of 5 m x 5 m in a study area of 75 m x 75 m. Pesticidal leaf powder of H. suaveolens, O. suave and D. ambrosioides were used at the rates of 0, 30, 60 and 90 g 1.5 kg-1 of cowpea seeds in storage. The results showed that, all FMPs attracted a good number of pollinators, but O. suave attracted more pollinators than the rest of FMPs. More pods per plant were produced in open pollinated bean plants than in self-pollinated (netted plants) and the control plots (no margins). Higher dosages of plant leaf powders at 60 and 90 g for H. suaveolens and D. ambrosioides and 90 g for O. suave significantly (P ≤ 0.001) affected insects’ mortality, survival and reduced seed damage. Comparatively, H. suaveolens and D. ambrosioides at 90 g was more effective in inhibiting egg deposition by C. maculatus just as successful as the positive control. Therefore, the findings of this study indicated O. suave to have high influence in attracting pollinators, while H. suaveolens and D. ambrosioides at high dosage were effective in protecting the stored cowpea seeds against C. maculatus.