Among insect orders, which shows the greatest diversity in aquatic habitats?

• A. Diptera
• B. Ephemeroptera
• C. Odonata
• D. Hemiptera

Answer: (D)

Diversity in aquatic habitats reflects how widely an order has adapted to living in water across different microhabitats. Hemiptera, the true bugs, include a broad array of aquatic lineages that occupy many distinct aquatic niches. You’ll find surface-dwelling water striders gliding on the water’s surface, mid-water swimmers such as backswimmers and water boatmen, and bottom-dwelling predators like water scorpions and giant water bugs that hunt among vegetation and mud. There are also aquatic plant dwellers and detritivores, all sharing the same order but occupying very different parts of the water column and associated ecosystems. Their piercing-sucking mouthparts support feeding on a wide range of prey and plant fluids, and their bodies show adaptations for swimming, walking on surfaces, or living among submerged vegetation. This combination of varied habitats and lifestyles within a single order explains why Hemiptera shows the greatest diversity of aquatic habitats among the options.