Correct Option: C. European corn borer Detailed Explanation: The European corn borer (Ostrinia nubilalis) is a significant pest of maize (corn) crops. This pest is notorious for its destructive feeding habits, particularly during its larval stage. Here’s a step-by-step breakdown of why the European corn borer is the correct answer:

1. Life Cycle and Feeding Habits:
2. The European corn borer undergoes complete metamorphosis, which includes the egg, larva (caterpillar), pupa, and adult stages. The larvae are the damaging stage.
3. After hatching, the larvae burrow into the stalks and ears of maize plants. This tunneling behavior disrupts the plant's vascular system, which is essential for nutrient and water transport.
4. Impact on Maize Plants:
5. The tunneling creates entry points for pathogens, leading to increased susceptibility to diseases.
6. As the larvae feed on the plant tissues, they weaken the stalks, which can result in lodging (the plant falling over) and wilting.
7. The damage to the ears can lead to reduced kernel formation and lower overall yields, significantly impacting the economic viability of maize production.
8. Symptoms of Infestation:
9. Farmers may notice wilting plants, stunted growth, and the presence of frass (larval excrement) around the base of the plants or inside the ears.
10. The presence of holes in the stalks and ears is a clear indicator of European corn borer activity.

Why the Other Options Are Incorrect:

• A. Aphids:
• Aphids are small sap-sucking insects that primarily feed on the phloem of plants. While they can cause damage by weakening plants and transmitting viruses, they do not tunnel through the stalks or ears of maize. Their impact is more related to stunted growth and leaf curling rather than structural damage.
• B. Corn earworm:
• The corn earworm (Helicoverpa zea) is another pest that affects maize, but it primarily feeds on the kernels of the ears rather than tunneling through the stalks. While it can cause significant damage to the ears, it does not have the same destructive impact on the stalks as the European corn borer.
• D. Leafhoppers:
• Leafhoppers are known for their ability to transmit plant diseases and can cause damage by feeding on the leaves. However, they do not tunnel into the stalks or ears of maize. Their feeding can lead to leaf discoloration and reduced photosynthesis, but they do not cause the structural damage associated with the European corn borer.

Summary of Key Points:

• The European corn borer is a major pest of maize, known for tunneling through stalks and ears.
• Its larvae cause significant damage, leading to wilting and reduced yields.
• Other pests like aphids, corn earworms, and leafhoppers do not tunnel into maize plants and have different feeding behaviors and impacts.
• Recognizing the specific damage caused by the European corn borer is crucial for effective pest management in maize cultivation.