What does the suffix "-ptera" signify in the names of most insect orders?

The suffix "-ptera" is derived from the Greek word "pteron," meaning "wing." In the context of insect orders, this suffix is used to indicate that members of these orders possess wings in their adult form. The capability of flight is a defining characteristic of many insects, allowing them to escape predators, find food, and locate mates.

The other options do not hold true for the classification indicated by the suffix "-ptera." While certain aquatic insects may have the ability to fly and can be members of orders with this suffix, "aquatic" does not inherently relate to wing characteristics. Not all insects that are predators or nocturnal have wings; hence, these traits are not universally signified by "-ptera." The primary focus of this suffix in insect taxonomy is specifically associated with the presence of wings in the adult stage of the insects.