Explain why the saprotrophs and detritivores are placed to one side of the pyramid

The saprotrophs and detritivores are placed to one side of the pyramid because they are decomposers which feed on dead bodies of all the living organisms which are present in the trophic levels i. e. producers, primary consumers, secondary consumers and tertiary consumers etc. When they feed on dead bodies, they released nutrients which are used by the plants.

not always but somethings can be reproduced in a laboratory.