What's a teneral? I'm under the impression it's an arthropod that had just emerged either from its pupa or larval exoskeleton, before its cuticle hardens. The appearance would be pale, without much recognizable color or patterning, and it's in this vulnerable state for only a very brief time. Yet one of your recent posts described an immature adult male common whitetail (which does have a recognizable pattern) as a teneral. You're not the only one I've seen describe immature adult Odes this way. Is there any sort of consensus on when to use the word?
This is a super good question!
Your initial assumption is correct! As you said, the term teneral refers to an arthropod that is still soft and discolored from emerging from its molt, be that a pupa or a previous nymph instar. For most arthropods, it only takes a few hours or less for the cuticle to harden, so this teneral period is very short.
Interestingly, Odonates are a bit different when it comes to this! When molting into their adult form, it can take Odonates days or even weeks depending on the species for their cuticle to fully harden and come into their full adult colors. Throughout this transition period, they are considered teneral, even if they are flying and have begun to display partial adult coloration. The common whitetail I posted is an adult male, but because he hasn't fully come into his adult coloration, he's still considered to be in his teneral stage.
For another similar example, here's a teneral Smoky-winged Dancer (Argia fumipennis fumipennis) I found the other day:
And here is what a fully adult female of this species looks like:
This example is a little harder to tell with than others since the teneral coloration in females is only a bit lighter than the adult colors. Males also start out as the pale brown of the top image, but, over the course of a week or two, they will transition to a brilliant blue-violet color!
The biggest signs of an Odonate being in a teneral form are shiny, soft-looking wings, often with pale wing veins and slightly cloudy wing coloration, as well as coloration inconsistent with their typical adult form. Many sites will include an image of a teneral adult for reference, but some don't. If the pattern of the species matches but the color itself doesn't, you might just have a teneral individual!
Unlike other flying insects that are flightless and vulnerable while in their teneral stage, once their wings expand a couple hours after molting, teneral Odonates do everything a full adult does except for mate. They wait until they're at their best and brightest to search for a partner! So, any adult Odonate that is in its adult form but hasn't come into its adult coloration yet is considered teneral, though you could also call it an adult and be correct.
This is a long-winded explanation, but I thought extra information would be nice to include. I hope this helps, and thanks for asking!!
