ABSTRACT

Arthropods are known to house a huge variety of microorganisms, and members of the Proteobacteria are among the most frequently found partners (Buchner 1965). One of the major peculiarities of arthropod-Proteobacteria associations is their ability to establish long-term intracellular symbioses, ranging from parasitism to mutualism and occurring at different levels of organism complexity and biotope. Among the Proteobacteria, mutualism most often involves the γ-proteobacterial

Introduction ................................................................................................................1 SpeciŒc Symbiotic Systems .......................................................................................2