International Journal Of Biology and Biological Sciences Vol. 2(1), pp. xx-xx, January 2013 Available online at http://academeresearchjournals.org/journal/ijbbs ISSN 2327-3062 ©2013 Academe Research Journals Full Length Research Paper Embryonic and postembryonic development of blister beetles (Coleoptera: Meloidae) in the world: A synopsis Karem S. Ghoneim Faculty of Science, Al-Azhar University, Cairo, Egypt. E-mail: kar_ghoneim@yahoo.com. Accepted 22 January, 2013 Blister (oil) beetles, family Meloidae, are distributed throughout the world except for New Zealand, Antarctica and most Polynesian islands. They are characterized by their complex biology including hypermetamorphosis and diapause. The present review discusses the embryonic development of several meloid species belonging to various genera. Concerning the postembryonic development, this work reviews the life histories of some meloid species focusing on the adult longevity, preoviposition period and oviposition period. It reviews, also, the adult reproductive potential of several species and pays some attention for the immature stages, particularly the larvae of bee - and grasshopper- associated beetle species. Trials had been achieved for maintaining laboratory colonies of some meloids in different parts of the world for which failure was reported more than success. In addition, the present work shed some light on the diapause in Meloidae as an escape in time from the unfavorable environmental conditions. Key words: Blister beetles, embyogenesis, hypermetamorphosis, triungulin, longevity, oviposition, fecundity, fertility, diapause. INTRODUCTION The family Meloidae (order Coleoptera) is commonly known as oil or blister beetles. Meloid species are widespread throughout the world except for New Zealand and Antarctic (Arnett et al., 2002). Distribution of meloid genera over the different zoogeographical regions was shown by Bologna (1991a, b). As reported few years ago, Meloidae contains more than 3000 species of 120 genera (Dettner et al., 1997; Arnett et al., 2002) and primarily inhabit the temperate and arid regions, as well as the sub-tropical and tropical savannas or other open habitats (Bologna and Di Giulio, 2011). The Meloidae is one of the most interesting of all Coleoptera families on account of the remarkable biology; hypermetamorphic, that is, the first instar larva is active and campodeiform, while the subsequent larval instars are sedentary and scarabaeiform. The larvae are semi- parasitic predators, usually feeding either in the nests of bees on the larvae and food stores, or on the egg cases (oothecae) of grasshoppers (Selander, 1987; Bologna and Pinto, 2002). Postembryonic development includes 7 larval instars and 5 distinctive phases. The first instar larva has usually received the name of triungulin (more recently planidium) because of the peculiar shape of pretarsus, specialized in some genera for climbing and holding the host (Gillott, 1995; Di Giulio and Bologna, 2007). Adult beetles can be recognized by morphological characteristics such as soft body, bright coloration, rather elongate, head deflexed with narrow neck, pronotum not carinate at sides, heteromerous tarsi, and smooth integument (Borror et al., 1981, 1989; Bologna, 1991a, b; Arnett et al., 2002). They are phytophagous, and certain groups, on account of their moderate size and swarming behavior, can cause considerable damage to crops by feeding on the foliage or flower heads (Greathead, 1963; Booth et al., 1990). Thus, a species may often be beneficial to agriculture as a larva, helping to control grasshopper populations, yet be a pest as an adult (Mayer and Johansen, 1978). Diapause is a behavioral and physiological characteristic of blister beetles. It is a delay in development in response to regularly and recurring periods of adverse environmental conditions (Tauber et al., 1986). Understanding of diapause as a “ process”, rather than as a “status”, is now widely accepted by the research communities with insects (Tauber et al., 1986; Danks, 1994; Hodek, 2002). Generally, diapause in insects is a dynamic process consisting of several distinct