Final answer:
The major class within the subphylum Hexapoda is Insecta, which constitutes the largest class of arthropods. Insects are the most numerous group of organisms on Earth, with over 10 million species. Examples of insects include ants, cockroaches, butterflies, and bees.
Step-by-step explanation:
The major class within the subphylum Hexapoda is Insecta. Insects make up the largest class of arthropods, with more than half of all known organisms being insects. There may be more than 10 million species of insects in the world, most of them yet to be identified. Examples of insects include ants, cockroaches, butterflies, and bees.