Farmers are faced with a lot of problem in monitoring insect pests of stored cowpea. The standard probe trap is used to monitor C. maculatus infestations in stored cowpea but it is not efficient in trapping the insect due to variation in atmospheric conditions leading to inappropriate management decisions regarding the action threshold. Its perforation size (3 mm) is specific to C. maculatus which cannot be used for other larger bruchids like C. subinotatus, infecting cowpea. A research was carried out in the Entomology Laboratory of Nigerian Stored Products Research Institute, Kano, Nigeria, between March and October 2016, to examine the possibility of incorporating light into a locally fabricated probe trap, with the aim of developing an improved trap for detecting bean weevil. Six different colour lighted probe traps were evaluated, together with a control and a standard trap in order to determine the performance of respective trap in the detection of cowpea weevils. Each treatment was repeated three times, in three different insect densities: low (3 insects per kilogram of cowpea grain), medium (7 insects per kg) and high (15 insects per kg). Two weights of grains (10 kg and 100 kg) were used to determine the effect of grain volume on the performance of the fabricated probe trap. Trap catches was recorded every 24 hours for five days. Data collected was subjected to ANOVA and means were separated using SNK at 5 % confidence level. The result indicated that ambient light source was more effective in improving the performance of the modified probe trap for early detection of C. maculatus infesting stored cowpea, thresholds for management decisions were also determined and the fabricated trap was economically profitable; hence, objectives of the study were achieved. Commercialization of the improved probe trap is therefore recommended.