Losses caused by Mylabris pustulata Thunberg in pigeonpea and mungbean at various beetle densities were assessed under net house/caged and field conditions. The observations revealed that the blister beetle caused considerable crop losses to both the pigeonpea and mungbean crops as under net house conditions, M. pustulata Thunberg at 200 beetles/cage caused the maximum reduction of 54.18, 20.15 and 64.88 per cent in pod setting, seed setting and grain yield in pigeonpea, respectively. Similarly, in mungbean, M. pustulata Thunberg at 4 beetles/cage caused maximum reduction up to 67.14, 26.65 and 75.29 per cent in pod setting, seed setting and grain yield, respectively. However, under unprotected conditions, 46.77 and 35.90 per cent of yield losses were recorded in pigeonpea and mungbean, respectively as compared to 0% under protected conditions. Thus, justifying that M. pustulata Thunberg is a major threat to both pulse crops and needs to be managed efficiently to avoid the significant crop losses caused by it.