Odonata Life Stage Annotation

Based on Scott Loarie's suggestion following an inquiry, I am inviting the more active iNaturalist odonatists and a couple of admin types to a discussion regarding the life stage annotation options relating to Odonata. Annotations are kind of a new thing (introduced last fall?), and I think they can use some refinement at least with regard to odonates. The current life stage options for odonates are Egg, Nymph, Teneral, Adult.


My biggest issue is with the Teneral option. Teneral is a condition following molt—not a stage in between nymph and adult. Odonates are teneral at the beginning of adulthood (not before adulthood) following their molt out of nymph-hood. This has led to some disagreements with other iNat users who insist that a particular odonate is Teneral, not Adult. An adult odonate is Adult, whether or not it is teneral. Have I beaten this dead horse sufficiently?

While the teneral description is most commonly used for adults immediately following their emergence, I point out that an odonate is teneral every time it molts from one nymph stadium to the next. So, an adult odonate has been teneral multiple times while it was a nymph, and then one final time when it became an adult. Another way to put it is that an odonate can be a nymph AND teneral as well as an adult AND teneral. I also have to point out that the teneral condition is experienced by all arthropods following molt. It's isn't limited to odonates, but I have only seen the Teneral annotation associated with odonate submissions on iNaturalist.

My recommendation is to drop the Teneral option from the life stage annotation for odonates (and any other arthropods for which it is an option). Any submissions which are currently annotated as Teneral, I would simply change to Adult. Personally, I don't see the value of annotating teneral adults differently from other adults, but if anyone does perhaps options like "Adult (teneral)" and "Adult (mature)" make sense. But, again, I don't see the value of doing so, especially since it can be a rather subjective call.


Here's another category that I ponder, although I don't have a solid recommendation. For those submissions which are based on exuviae only—the vacant nymphal "skin" left behind following emergence (here's an example: https://www.inaturalist.org/observations/1600819), what is the best way to annotate them?

Visually/structurally exuviae are nymph-like, and since nymphal characters are used to identify exuviae, I can see annotating them with Nymph. However, viewing such a submission strictly through the lens of life stage, the Adult annotation could make sense since the individual that left its "nymph suit" behind has moved on to adulthood (and is presumably flying around somewhere). On the other hand, during periods of no precipitation or in some sheltered situations (like under a bridge), exuviae can persist beyond the adult life span of the individual that left it behind.

Perhaps an additional category of "Exuviae" make sense to distinguish it from Nymph and Adult, even though it isn't really a life stage. I guess this makes the most sense to me although I'm agnostic on it, and I'm particularly interested in opinions (more so than the Teneral topic). Like the teneral condition, exuviae is a general arthropod thing not limited to odonates.

Any thoughts? @greglasley @briangooding @nlblock @aguilita @vicfazio3 @sambiology @scottking @ericisley @cordulegaster @joshualincoln @jcabbott @loarie @kueda

Posted on April 28, 2018 11:48 PM by jimjohnson jimjohnson


I have identified some odonates as teneral because they were males that had the wrong colors for an adult male, but I do understand what you have shared.

Posted by bluebell101 about 6 years ago

@bluebell101, they have the "right" colors for a teneral adult male.

Posted by jimjohnson about 6 years ago


Posted by bluebell101 about 6 years ago

For me teneral applies to the still soft and unhardened Ode, wings are soft and shiny and their bodys are also soft. Not sure how long it takes the wings and bady to harden or become rigid.. Maybe just immature adult, and mature adult ?

Posted by ericisley about 6 years ago

@ericisley, I still have to wonder what value it adds to make the distinction among multiple types of adults (regardless of what we call them). How much difference would it make in the life stage graph, for instance? Or is this something that users would use as a search filter?

Posted by jimjohnson about 6 years ago

@jimjohnson For me personally I have no need for the term teneral, other then to let someone it's newly emerged adult and some people might use that to help ID some dragons, I know some wing markings can be so pale, they can't hardly be seen right after emergence. Once they have emerged they are adults in my book and if the term teneral wasn't listed it wouldn't bother,, Egg, Nymph and Adult would be fine for my needs.

Posted by ericisley about 6 years ago

My initial thoughts were that the term “teneral ” is a bit subjective and unnecessary and that I would be fine getting rid of it. Perhaps the only time one might have cause to use it is when an ode is half or more out of its skin and not yet fully “inflated”. However if one wanted to mine data for when tenerals are observed in different locals and we did not have that designation we could not do so.

Regarding exuvia, since we are looking at Nymph “casings” and using the same criteria to id them, I don’t think they warrant a separate division if we are just looking for presence or absence of an ode.
That being said, if there was a separate category for exuvia an argument could again be made for the knowledge that might be gained from mining that data in the future.

If separate, might we over time get some rough information on emergence that would not be mineable data otherwise.
Might both of these categories over time be used to evaluate emergence over long periods and see for example how it relates to climate and other environmental changes?

Posted by joshualincoln about 6 years ago

I find teneral to be a useful annotation in some situations, such as when trying to get a more accurate handle on how long the first adult of the year seen at a site has been flying. However, I agree that it should not be considered a separate life stage annotation. Tagging it in some other way would be better.

Posted by nlblock about 6 years ago

Jim, after reading your description for "teneral" I understand your point of view more. Until now my interpretation of "life stage" concerning this topic was a bit looser based on what I was interested in seeing with the data. I definitely agree that the level of subjectivity in labeling an organism as teneral is problematic.

My hopes in using the annotations were to be able to look more in-depth at phenological data (especially utilizing instances of ephemeral periods like the organism being teneral or juvenile) to aggregate/assess data about emergence patterns and possible relation to environmental (or possible other) factors on a longitudinal scale.

I felt that the ever-expanding amount of data (admittedly, though not following any methodology) here could be good for gleaning information and maybe give ideas for a more structured study. What I was hoping to look at involved exporting the data and manipulating it elsewhere, though not necessarily looking at it through the iNaturalist platform.

As for exuviae I had similar ideas though exuviae obviously persist and cannot be estimated in photos. I think it doesn't make sense to have exuviae as a "Life Stage" value from a strictly semantic point of view but some odonates may be hard to find as adults and being able to search for the exuviae through iNaturalist could be helpful in identifying them/the origin of their larval habitat. This could also be achieved through an Observation Field though are much less intuitive.

I understand your point of view and from a strict sense it is possible "egg", "nymph", and "adult" make the most sense. If that is the result, I hope there is some other way we can add more data to observations and relatively simply be able to access and manipulate it.

Posted by briangooding about 6 years ago

Thanks for that description of a teneral, Jim. Given the wide range of people experience that iNaturalist taps into, I vote for making this annotation as straightforward, clear and unambiguous as possible. I think you will get greater uptake, and the data will be much more reliable and usable.

Posted by johntann99 almost 5 years ago

Why bother recording an adult phase at all?
After reading this journal, I started annotating a bunch of dragonfly observations. All of them, of course, were adults. I would think that of all the dragonfly observations that I have come across, less than 1% would be for anything but adults. So, why bother? Sure, annotate if it is NOT an adult, and whether it is male/female and other useful stuff. However it seems silly to me to offer an option that requires extra human effort, but is effectively redundant information.

Posted by johntann99 almost 5 years ago

@johntann99, that information can be used in filters and is used in the life stage histogram found on each species page. Whether that histogram is useful or of interest to anyone is open to debate, of course, but intentionally leaving out information on selected submissions doesn’t seem particularly useful either. I don’t find annotating my own submissions a burden.

Posted by jimjohnson almost 5 years ago

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