The blister beetle Meloe rugosus Marsham, ( Coleoptera : Meloidae ) was recorded for the first time as a serious insect pest attacking winter crops , particularly faba bean ( Vicia faba L.) and wheat ( Triticium aestivum ) in Farafra Oasis, western desert of Egypt. Beans, peas, alfalfa, Egyptian berseem, onion and the wild weed, Meliolotus indica L. were also recorded as host plants of this species. Adult beetles are phytophagous feeding plant foliage and flowers and under the stress of high population, plants may suffer death. Beetles occurred from early as November until late May. Through field observations in mid-January, the mating stage begins, where the male and female meet through the female sex pheromone. It was noted that the male searches for the female in the early morning, and when one of them meets the other, the mating stage initiate and the eggs are laid in the soil. During swarming and feeding, beetles secrete cantharidin fluid, a potent blister agent and long-term health threat to nearly all livestock feeding on plants hay. Field observations on insect behavior, eggs, crop damage, and activity and host plants were briefly explained.