Which adaptation is unique to insects among all protostomes?

The evolution of wings and the ability to move by flying is a unique adaptation of insects among all protostomes. During the pre-adaptation, their wings might held the respiratory structures for greater exchange of gases or it function as a protective shields over their leg joints. 

Moreover, like dragonflies that are unable to tuck their wings when at rest, the next evolutionary burst is the foldable wings they have. These insects includes locusts and stoneflies.

a

explanation:

many plants naturally reproduce this way, but it can also be induced artificially. horticulturalists have developed asexual propagation techniques that use vegetative plant parts to replicate plants. success rates and difficulty of propagation vary greatly. monocotyledons typically lack a vascular cambium and therefore are harder to propagate.