ABSTRACT
This chapter presents an overview of the knowledge concerning the diversity of endosymbioses in pentatomomorphan insects, with a special focus on the well-studied symbiotic systems of the southern green stink bug, Nezara viridula and the kudzu bug, Megacopta cribraria. Symbiotic bacteria generally show strict host tissue tropism and are localized in specialized body parts called "symbiotic organs." Locations of symbionts are diverse in insects, ranging from extracellular within the lumen of intestinal symbiotic organs called "crypts" to intracellular within specialized cells called "bacteriocytes". Phytophagous species of the superfamilies Pentatomoidea, Coreoidea, and Lygaeoidea commonly develop midgut crypts in the posterior region of the midgut, although the morphology and arrangement of the symbiotic organ are diverse. Symbiotic associations with bacteria occur in many animals, plants, fungi, and protists, among which insects are regarded as the largest group that takes significant advantages of bacterial symbionts. Diverse modes of mechanisms for symbiont transmission have been identified in several insect groups.
