Hi Bob-
I'm not sure what you mean. Are you talking about the option to indicate whether the insect is an adult? I left that empty, despite being sure it was an adult, because I wasn't familiar with the species. I don't see the change you mention having done.
I presume the move means this has been definitely identified as M. sexta?

The type of species does not matter. For all of Lepidoptera, if it is no longer an egg, a caterpillar or a pupa, then it is probably an adult, even the (few) wingless females.
For most of class Insecta, if it has fully developed wings, then it must be an adult. Larvae do not develop wings and only the order Ephemeroptera (Mayflies) have a sub-adult stage with wings.

This setting is logged by the system, for the two different browsing options in this order and we have to check one of those two boxes for every image that we place.
I normally check this box over and over again, during the course of the day for (new) people. Sometimes I leave a message, like the one above.
Experienced users always check these boxes, because they probably were told to do so at some point or they just know that it needs to be done. It's written on the submit form. "Check all the following that apply to this image:"