Published online by Cambridge University Press: 31 May 2012
The hydrogen-ion concentration of the alimentary canal of insects has been studied by many workers. In their review of this subject, Day and Waterhouse (1953) conclude that the pH of the foregut is often the same as that of the food, that of the midgut varies in different species from 3 to 10, but that of the hindgut rarely varies far from neutrality. Various methods of determining pH and their relative merits have been discussed by Waterhouse (1940). He considers that incorporating pH indicators into the food is the most accurate method with insects that are too small to enable their gut pH to be measured electrometrically.