Wild or captive-Rare parasite emerged from wild caught animal while in captivity

I’m an entomologist. I collected a wild scorpion last summer that has been kept isolated ever since, held in a different state from where it was collected.

Recently a parasitic fly came out of it. It’s a very rare find, rare enough that the species isn’t even on iNat yet. From what I can find in the literature there may be as few as 10 of these ever collected so it’s very much worth documenting. Eggs were laid in the scorpion in the wild but took at least 8 months to develop and come out, emerging in my laboratory.

I can pinpoint within a few hundred feet where the scorpion was collected in the wild. Can I list this observation as wild? I’d give an explanation in the comments.


I would say yes. when you collected the scorpion, you were not aware of the fly. I suppose a similar scenario would be if a raccoon moved into someone’s garden shed without the owner being aware of it’s presence. The raccoon would still be a wild animal.


An explanation would be great, but I’d say absolutely yes, please do add this observation as wild.


I would say wild, as everyone else has said, BUT mark the observation where you were keeping the scorpion, not where you collected it.


Why mark the location where it emerged from the scorpion, rather than the location where the scorpion was collected? Especially since the observer knows the eggs must have been present at the time it was collected?
Might using the location after the scorpion was moved give an erroneous account of the range of the fly (depending on how far it was moved: maybe a “different state” is in an entirely different region)
Especially if this is a species that has not be observed, that might skew the data going forward.


The fly eggs may have been present on the scorpion when it was collected, but the flies did not emerge at that time and place – you don’t know where the scorpion would have been at the time the flies emerged if it had not been collected, or whether the transfer to the lab environment affected their development rate. In other words, the location where the scorpion was collected does not reflect the situation where the flies were seen.

One thing that probably would be useful would be to post an observation of the scorpion from the time/location of collection and link to it in the later observation of the flies, so as to include a record of the history of the organism and the circumstances where it was found.

Hitchhiking organisms are tricky and a subject of regular debate, but I think it is important to remember that this is also a means by which organisms can potentially disseminate themselves and expand their range, so recording the time and location where the adult flies were seen reflects that.


I agree with others - you can post the flies as wild but in the location where the flies were with the scorpion in captivity. You can note the capture location in notes or a comment.

The (inferred) eggs were present 8 months ago at the other location.

Another issue with posting the flies at the original location/date of collection is that the phenology would be incorrect/misleading.

More philosophically, an iNat observation records an interaction between an organism and the observer - for you and the flies, this happened “now” (not 8 months ago), so that is the best date/location for the observation.

I agree that posting an original photo of the scorpion at the collection location/date and linking it would be great. There may also be some good observation fields for parasites that you could add, though I don’t know personally what those are.


Thanks for clarifying the reasoning on that.

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With collected specimens the collection date and location is used, not the photography date and location


Yeah, but this is different. I don’t see how it’s any different from a hitchhiker, which are marked at the location found.

Plus we don’t technically know for a fact the parasite was on the scorpion when collected, that’s only an assumption.


I find it logical to use the locality where the scorpion has been captured, if it can be excluded that it got parasitized in the laboratory. If the lab conditions agree more or less with the ones in the natural habitat, then I don’t see any problem with confounding the phenology of the fly. The locality of the lab is arbitrary, could be in a different continent, and the fly didn’t get there by its own means. So in my opinion using the lab locality would confound the fly’s natural distribution, apart from that the scorpion collecting site might be a new distribution record for the fly.

Own observation of a parasitoid fly, in this case only 20 km from where the infected katydid was collected and emerged after just 18 days:


I would agree with posting it with the original location, with a note explaining what you explained here. To me, unless there is potential for the scorpion to pick the fly eggs up in your home state (which you don’t seem to think so), then the flies should be logged where they were last seen in nature, where they were in the scorpion originally.

IF there is a chance that they could have come from the substrate of the tank, a feeder, etc, than to me that would warrant marking as captive. You’d know more about this parasite than I given your research on it.


A collected (killed) specimen has not undergone further development after the date of collection – i.e., the life stage, phenology, etc. all represent the point in time of collection.

In this case, however, the adult flies were not present when the host was collected.

I don’t think the original poster was considering using the date of collection, the question was whether the location should be where it was collected or where the flies emerged.

For me, the guidance on iNat is clear – it should be the location where they were observed several months later, not where the specimen that carried them was collected, even if this is outside the expected range of the species. Data like this is always going to have to be analyzed in the context of the circumstances of the find; the point on the map doesn’t tell the whole story. Linking to an observation of the host at the time and location of collection seems like a reasonable way to represent this history.

Some of the discussions on raising caterpillars and hatching gall wasps may be relevant (though these count as “captive” at the time of emergence because the organism being observed was intentionally collected rather than an accidental passenger). See e.g.:


I agree with danly if you set the observation at where it emeged, which he said was in a different state. It makes a confusing range for a species which may not even be found in the state his lab is located in

Hitchhiking involving humans is a common part of animal movements, and has been for many thousands of years. Reality is more complicated than what you want a range map to look like.


I understand hitchhiking as potentially intentional, and a possible means of extending the distribution of a species, like oak katydids travelling on cars. The fly eggs/larvae inside the scorpion have been moved arbitrarily. The locality of the lab where the fly emerged is irrelevant.

It’s not irrelevant, it’s the only place the fly was known to occur wild. It’s more accurate than guessing where it may have been. Using that old location would result in the date being inaccurate and the phenology being messed up.

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I disagree with this, and the approach is also not how iNat guidelines ask us to treat situations like this.

Please see some of the linked discussions above which explain why this approach is problematic and shouldn’t be used.


Thank you all for the answers and interesting discussion.

To touch on a couple points- There is zero chance the flies came from my current location, the laboratory they are kept in is a USDA containment and quarantine facility and they have been isolated from other animals. Ironically it is a containment facility because of parasitoids similar to the ones in question here, and the presence of ‘wild’ ones in the lab area would have been immediately noted and caused for alarm. The container the scorpion was housed in was completely fly proof.

I will be creating an observation for where the scorpion was found in its native area and back date the observation to the date of collection last summer. The animal is now dead from the flies but I will list it as it was alive then.

I will create an observation for the flies with their location as my lab’s location, and link it to the host scorpion’s observation with accurate date/locality info for when it was collected, along with GPS coordinates for where it was originally collected.

The flies are still alive and we are waiting for them to die of natural causes before we take better photographs and submit the observations.


Can you really call it wild when it’s been moved to it’s current location in an escape-proof box, specifically designed to prevent this exact species of fly from escaping? From Bugguytad’s comment, it seems like they have taken extensive steps to ensure that these flies don’t escape, that seems like the definition of captive to me.