The correct option for the question "An arthropod that is destructive at early stage of its life cycle is" is A. butterfly. Explanation of the Correct Answer

1. Understanding the Life Cycle of Butterflies:
2. Butterflies undergo a complete metamorphosis, which includes four stages: egg, larva (caterpillar), pupa (chrysalis), and adult (butterfly).
3. The larval stage, commonly known as the caterpillar, is where the destructive behavior occurs. Caterpillars are known to feed voraciously on leaves, which can lead to significant damage to plants and crops.
4. Destructive Nature of Caterpillars:
5. Many species of caterpillars are herbivorous and can consume large quantities of foliage. This feeding can weaken or kill plants, making them a pest in agricultural settings.
6. For example, the larval stage of the cabbage white butterfly (Pieris rapae) is notorious for damaging cabbage and other cruciferous crops.

Why the Other Options are Incorrect B. Mosquito: - Mosquito larvae (commonly known as wrigglers) live in water and feed on organic matter and microorganisms. While they can be a nuisance and are vectors for diseases, they do not cause significant destruction to plants or crops in the same way that caterpillars do. Their impact is more related to public health rather than agricultural destruction. C. Bee: - Bees, particularly in their larval stage, are not destructive. They feed on pollen and nectar, which are essential for their development. Bees are crucial for pollination and the health of ecosystems and agriculture. They do not damage plants; rather, they help in the reproduction of flowering plants. D. Millipede: - Millipedes are detritivores, meaning they primarily feed on decaying plant material and organic matter. While they can sometimes damage young plants, they are not typically considered destructive pests in the same way that caterpillars are. Their role in the ecosystem is more about decomposition and nutrient cycling. Summary of Key Points

• Butterflies: The larval stage (caterpillar) is destructive to plants, feeding heavily on leaves.
• Mosquitoes: Their larvae do not damage plants; they are more of a health concern.
• Bees: Larvae feed on pollen and nectar, aiding in pollination, not destruction.
• Millipedes: Feed on decaying matter, not typically harmful to living plants.

Revision Summary

• The correct answer is A. butterfly due to the destructive feeding habits of caterpillars.
• Caterpillars can cause significant agricultural damage by consuming large amounts of foliage.
• Other options (mosquito, bee, millipede) do not exhibit destructive behavior towards plants in their early life stages.
• Understanding the life cycles and ecological roles of these organisms is crucial for distinguishing their impacts.