Comments on insect defense mechanisms

Abstract

Insects constitute a very diver- se group whose survival and success in a great variety of ecological niches involves an effi- cient defense system. This paper aims to provide an overview of existing general information on defense mechanisms of insects with special emphasis on cellular and humoral components of innate immunity. The first is concerned with mediated immune responses by hemocytes: phagocytosis, nodulation and encapsulation. As for humoral defense, it includes production of antimicrobial peptides and the complex enzyme cascades which regulate coagulation of the hemolymph and melanization. Moreover, information on mechanisms of adaptive immunity is included. While research in the field of defense mechanisms of insects is extensive, given the intraspecific and interspecific variability they present, much remains unknown. To increase studies on the various aspects that still remain unknown is of interest and applicability in pest management strategies as well as with respect to insect vectors of diseases in humans and in animals of commercial interest.