Disposal of Frass in Mines

Abstract

Only a small part of the matter consumed by the mining larva while feeding is made use of to build up its body; the assimilated matter consists largely of protein products and while the remainder may undergo a change as a result of digestive action, it is not assimilated by the body. The chlorophyll from the plant is transformed into the dark green chlorophyllan while passing through the alimentary canal. The starch which comprises such an important part of plant cells is not attacked by the mining larva, according to the investigations of Haberlandt. Naturally enough, the tougher parts of the larva’s diet, such as the walls of the cell with their high cellulose content and the thickened strengthening elements, (sclerenchyma fibres and cells), and also conducting vessels with their frequently thickened walls are excreted undigested. Since the larva eats almost uninterruptedly — apart from feeding pauses while changing skins — there is also a continuous excretion of frass, which contains undigested elements and matter changed by digestive processes.

The online version of the original chapter can be found at http://dx.doi.org/10.1007/978-94-015-7196-8_31