In some bioluminescent chironomid midges, light emission is produced by which excretory organ?

In some bioluminescent chironomid midges, light emission is produced by which excretory organ?

• A. Midgut
• B. Fat bodies
• C. Oenocytes
• D. Malpighian tubules

Answer: (D)

Light emission in these bioluminescent chironomid midges comes from photogenic tissue that is housed in the Malpighian tubules, the insects’ excretory tubes. These tubules form lantern-like structures where light-producing reactions occur, which is why they serve as the light-emitting organ. The midgut is the digestive tract, the fat bodies are mainly energy storage and metabolic tissue, and oenocytes handle lipid processing and detoxification—none of these are the sites of light production in these midges. So the excretory organ responsible for the glow is the Malpighian tubules.

Light emission in these bioluminescent chironomid midges comes from photogenic tissue that is housed in the Malpighian tubules, the insects’ excretory tubes. These tubules form lantern-like structures where light-producing reactions occur, which is why they serve as the light-emitting organ. The midgut is the digestive tract, the fat bodies are mainly energy storage and metabolic tissue, and oenocytes handle lipid processing and detoxification—none of these are the sites of light production in these midges. So the excretory organ responsible for the glow is the Malpighian tubules.