Why are there so few sightings of this wasp?

Hi everyone. I have a question about this wasp - (Trichomma fulvidens).
There are only 4 sightings of this wasp recorded on iNaturalist.
On GBIF - only 183. When there are hundreds of thousands of other fixed insects.
Is she some kind of rare or something?


Ichneumonids are very difficult and there are few IDers on iNat who specialize in this group. A huge percentage of observations in this family are at family level, either because the photos are insufficient for ID, or because no expert with the relevant expertise has looked at them.


To me, it seems you have answered your own question.
However, I know nothing of wasps, let alone this particular beauty.
I am sure more knowledge people will comment. I am especially looking forward to the perspective of those with affinity with wasps.

Welcome, @jigimond! It’s pretty much what everyone has said so far: wasps are tricky. I do my best with local species, but I can get tripped up fairly easily. (The closest I come to a specialty is Odonata.)

She is awfully pretty, isn’t she?


What a beautiful individual you found!
On top of what everyone else said, be careful, outside of Vespa, Vespula, and Polistes, wasp ID on inat is often to family, maybe coarser, very few are even at genus, and that is probably where they belong, for now.

In fact, I believe there is a problem here of many wasps being IDd to species when they belong at genus at best…

I suspect what happens is that one observation is IDd to species, then the inat CV suggests all similar wasps to be that species, and so people ID as such, and it creates a feedback loop. For example -
Using Pimpla rufipes, a larger, charismatic species, which is easier to ID than many of the smaller wasps, you find 1,975 verifiable observations, and for Pimpla 6,456 verifiable observations. (links below).
Pimpla contains ~200 described species, is it likely that 30% of all Pimpla observations be Pimpla rufipes? Depending on distribution, life history, perhaps, but I suspect that Pimpla rufipes was simply the most ‘popular’ Pimpla species, correctly or incorrectly, and the inat CV ran away with that ID.

Those are my rambling speculations anyway, you can repeat this with many wasp species, it happens commonly in Ichneumonoidea, or perhaps this is just due to my own poor wasp ID skills.




Some species are very common and some are very rare. I don’t think anyone knows why some species are naturally uncommon (not counting those that have become endangered due to specific human activities). And then there are species that are common, but uncommonly documented because they are secretive.

Here’s a summary from this article:
“I have discussed two of the most robust patterns in community ecology: (1) the skewed pattern in species abundance, in which a community contains many rare species and only a few common species and (2) the positive distribution-abundance relationship, in which widespread species tend also to occur in high abundance throughout their range. Understanding these patterns has important implications for practical issues like reserve selection and predicting extinction risk. Two independent approaches seek to explain these emergent patterns. The first focuses on neutral dynamics with patterns in species abundance and distribution arising from stochastic occurrences of birth, death, immigration, extinction, and speciation. The second focuses on niche differences among species as the driving force behind the abundance and distribution of a single species, and hence the emergent patterns across multiple species. Both may be operating simultaneously, constituting different endpoints of the same continuum.”

And a more detailed article (book chapter) here:


That genus appears to be limited in range, which might be part of it.

In my experience, Ichneumonidae are quite skittish, much more so than other wasps, so can be difficult to photograph.

It could be that they are seen more often than they are documented. I have often seen things I cannot take photos of in time, or the photos turn out blurry or otherwise useless. (I think I am not the only one.)


You are not the only one! I was thinking the same thing. Some species can be difficult to photograph!

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To answer this specific question: Trichomma fulvidens is common in some parts of Europe, but not in others (e.g. the UK). It’s relatively easy to identify from good photos (general Gravenhorstiini look + obvious eye hair + largely black face), so will have more records than many equally common species.


I would say yes! It is genuinely more common than other Pimpla, and has an easily visible character (orange hind tibiae) distinguishing it from other fairly common species like turionellae.

It takes more than one ID for a species to be considered for the CV model (I think 50 community IDs?), and there’s only the feedback loop you describe if a second identifier inappropriately treats the CV suggestion as more than a suggestion.


If I recall correctly, a minimum of 100 RG observations are needed to be included in the model. So that slippery slope of just one ID won’t be enough to influence the CV. But otherwise, yes, incorrect CV identifications could create a feedback loop since many casual users just accept the CV recommendation.

CV needs 100 pictures (from various observers)
So about 60 obs - since we can’t count photos.

PS thanks for the new FAQ - added to my copypasta

CV is updated each month.
Click the internal insects link to see what species were added (filter by location)
Using data from 26 November 2023


Here’s the updated FAQ about which taxa are included in the CV model: https://inaturalist.freshdesk.com/en/support/solutions/articles/151000170368-which-taxa-are-included-in-the-computer-vision-suggestions-


Quoting this part for emphasis:

Observations do not need to be Resarch [sic] Grade in order to be used in training, but observations with a matching Community ID will be prioritized.

So no second identifier is needed after all:

Cheers! That ties in with the information pfau_tarleton linked to also. Pimpla rufipes is also featured as the representative of Pimpla in this readily available guide (linked below), so I can imagine people default to rufipes when looking for information online, I know I have been guilty of this.


Thanks; it’s gotten more nuanced since I last checked! So the model can be trained on observations for which there’s only one identifier, but it will be tested against observations with a community ID, for which at least two identifiers are needed.

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CV needs 100 pictures (from various observers)
So about 60 obs - since we can’t count photos.

I would agree! I am one of the few observers in the average 10 mile radius of where 95% of my observations come from and I suppose you could say for the entire county at large. So what you see in the iNat details for my area is skewed to what may interest me and as a generalist that will be a lot more than the average bird watcher or those who shoot fungi.

I’ve had times where all frogs no matter what species I uploaded were coming up as Grey Tree Frog for my county and I had to assume that was because I has shot so many of my Grey Tree Frog Complex that year. Without a doubt I’m the most prolific (old guy with a camera with nothing better to do) generalist nature photographer in the area perhaps exceeding the total of all others combined for the county.

That is not to brag or pat myself on the back (iNat is not a contest to me) but to underscore your point of just how important that the observations come from various observers.

Today, I kind of laugh when I see I have had something like a ground beetle ID’d by the experts and it is the only one documented for the county or sometime region (SE Michigan). It doesn’t make me a wizard at finding rare species to my area, what it really means is I’m the only one taking the time to shoot them. That is a bit disheartening because it suggests there are a lot of areas getting little attention of naturalists in particularly those that are generalists (but we have a bunch of them at Kensington Park where the birds eat out of your hands and lots of other tame-wild animals. LOL


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