Correct Option: B. Fall armyworm Detailed Explanation: The Fall armyworm (Spodoptera frugiperda) is a significant pest of maize (corn) crops, and it is known for its destructive feeding habits on both the leaves and kernels of the plant. Here’s a step-by-step breakdown of why the Fall armyworm is the correct answer:

1. Feeding Habits: The Fall armyworm primarily feeds on the foliage of maize plants, which can lead to reduced photosynthesis and stunted growth. When they feed on the kernels, they can cause direct damage to the yield, leading to significant economic losses for farmers.
2. Life Cycle and Infestation: The Fall armyworm has a rapid life cycle, allowing it to reproduce quickly and infest large areas in a short time. This pest can produce multiple generations in a single growing season, making it a persistent threat to maize crops.
3. Symptoms of Damage: Farmers often notice signs of Fall armyworm infestation through the presence of holes in the leaves, wilting, and the presence of frass (insect droppings). In severe cases, the entire plant can be defoliated, and the ears of maize can be damaged, leading to reduced yield and quality.
4. Geographical Spread: The Fall armyworm is not only prevalent in the Americas but has also spread to Africa and Asia, affecting maize production globally. Its adaptability to various climates and its ability to develop resistance to pesticides make it a formidable pest.

Why the Other Options Are Incorrect:

• A. Cotton bollworm: While the cotton bollworm (Helicoverpa zea) is a significant pest of cotton and can also affect maize, it is not as commonly associated with maize damage as the Fall armyworm. The cotton bollworm primarily targets cotton plants and is less of a threat to maize compared to the Fall armyworm.
• C. Aphids: Aphids are small sap-sucking insects that can affect a variety of crops, including maize. However, their feeding primarily weakens plants by extracting sap and can lead to the transmission of plant viruses. They do not cause the same level of physical damage to maize leaves and kernels as the Fall armyworm does.
• D. Whiteflies: Whiteflies are also sap-sucking insects that can affect maize, but they are more commonly associated with other crops like tomatoes and sweet potatoes. Their impact on maize is generally less severe compared to the direct feeding damage caused by the Fall armyworm.

Summary of Key Points:

• The Fall armyworm is the most damaging pest to maize due to its aggressive feeding on leaves and kernels.
• It has a rapid life cycle and can quickly infest large areas, leading to significant economic losses.
• Other pests like the cotton bollworm, aphids, and whiteflies are less associated with maize damage compared to the Fall armyworm.
• Understanding the specific threats to maize crops is crucial for effective pest management and ensuring high yields.

This comprehensive understanding of the Fall armyworm and its impact on maize will help you in your studies and preparation for exams in Agricultural Science.