Final answer:
The South American longhorn, reaching lengths of 6.5 inches, is a variety of Stick insect (d). These insects, part of arthropods, are known for their extensive camouflage and are among the longest insects in the world, contributing to their diversity and ecological roles.
Step-by-step explanation:
The South American longhorn, which can reach a length of 6.5 inches, is a variety of d) Stick insect. Insects are arthropods belonging to the class Hexapoda, and they represent the largest diversity of any group of animals on Earth, with an estimated 1 to 30 million species yet to be fully classified. Adult insects have various sizes, from the tiny fairy fly to the impressively long stick insect, some of which can measure up to 21.9 inches.
Stick insects are primarily known for their impressive camouflage abilities, mimicking the appearance of sticks or leaves to evade predators. They are among the longest insects in the world, which contributes to their common name. As terrestrial animals, they can be found in various habitats but are mainly known for dwelling in forests where they blend seamlessly with the vegetation.
It is fascinating that these insects, along with ants, beetles, and butterflies, experience different forms of metamorphosis. For example, beetles, flies, and butterflies undergo complete metamorphosis from their larval stages, whereas cockroaches and crickets develop through incomplete metamorphosis from their immature stages. The incredible variety of insects is further expanded by their roles in ecosystems, such as pollination, and the social structures seen in species like bees and ants.