The Hydrogen Ion Concentration in the Alimentary Canal of Larval and Adult Lepidoptera

Abstract

The pH of the midgut digestive juices of two species of carnivorous lepidopterous larvae and of 40 species of adult Lepidoptera belonging to 16 families was determined. In all species it was alkaline. From these records, and from those available from the literature for phytophagous, wool-eating, and wax-eating lepidopterous larvae, it is possible to generalize that midgut alkalinity is characteristic of the order Lepidoptera and that it is not dependent upon feeding habits.