Explanation:

• Insecta plecoptera (stonefly) is a sensitive insect that produces larvae in the water while the adults live on the land. The stonefly larvae are the indicators to the water pollution caused by the increase in the biological oxygen demand and the rise in temperature.
• Whenever there is an increase in the organic mass, the dissolved oxygen will decrease and the high rate of respiration of the algal bloom would also increase the temperature.
• Both these conditions are intolerable by the stonefly larvae and they die quickly. They need a high concentration of dissolved oxygen and normal temperature to survive. Hence, the correct answer is 'Stone Fly Larvae'.