author(s)
Soumita Pal and Prasun Karmakar

abstract
Insect guts are the most suitable breeding habitat for microbial colonization. There is a wide range of degree of dependence between insects and gut microbiota for basic functions. Insect digestive tracts differ significantly in morphology and physicochemical properties and that greatly influence microbial community structure. Midgut of lepidopteran larvae show extreme alkalinity (pH as high as 11–12, and alkaline conditions works better for their digestive enzymes. Exceptional condition is present in case of termites, with pH ranging from 5 to > 12 in the compartmentalized guts of some soil-feeding species. Lack of dependable transmission is the only obstacle to the evolution of intimate associations between gut microorganisms and host individuals. Social insects, such as termites,ants, and bees, are exceptions as they are provided with specialized beneficial functions in nutrition. There is still a large vacant place in information about insect gut communities. The extent of these roles is still unclear and awaits further studies.