Location: Integrated Cropping Systems ResearchTitle: Chapter 13. Physiology and ecology of host defense against microbial invaders Author
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 8/1/2011
Publication Date: 4/3/2012
Citation: Lundgren, J.G., Jurat-Fuentes, J.L. 2012. Chapter 13. The physiology and ecology of host defense against microbial invaders. In: Vega, F., Kaya, H., editors. Insect Pathology. 2nd edition. London, UK: Elsevier Publishers. p. 460-480. Interpretive Summary:
Technical Abstract: Insects mount a complex hierarchy of defenses that pathogens must overcome before successful infection is achieved. Behavioral avoidance and antiseptic behaviors by host insects reduce the degree of encounters between the insect and pathogens. Any pathogen that contacts or establishes on a potential host faces a series of barriers that restrict entrance into the hemocoel. Pathogens that enter the hemocoel are faced with a multipronged innate immune system. Humoral defenses primarily produce toxic molecules; hemocytes (granulocytes, plasmatocytes, oenocytoids) of the cellular defense have the capacity to phagocytose or encapsulate the target pathogen; and melanization involves both humoral and cellular components to produce several responses that are lethal to the pathogen. Intracellular pathogens must overcome cellular xenophagy and RNA interference (RNAi) defenses. Understanding how host resistance evolves and spreads throughout a population becomes important to preserve entomopathogens as a pest management tool. This phenomenon is well- studied in Bacillus thuringiensis, and the development of host resistance to this pathogen, as well as insect resistance management (IRM) strategies, is discussed.