Which of the following is a primary consumer in maize field...

Primary consumers are herbivorous organism, that feed on producers. In a food chain, grasshoppers are primary consumers, phytoplankton are producers, and wolf and lions are secondary and tertiary consumers respectively. Related Theory The amount of energy flow decrease with successive trophic levels as only $10 \%$ of energy is transferred from one trophic level to the next successive level. The energy is lost in the form of respiration and other vital activities to maintain life. If more trophic levels are present, the residual energy will be limited and decreased to such an extent that it cannot further support any trophic level by the flow of energy. So the food chain is generally limited to 3-4 trophic levels only.