Stiletto Flies of the World's Journal

One of the most interesting genera of stiletto flies is the genus Henicomyia. This extraordinary genus is found from SW USA throughout central America and as far south as Brasil. It a spectacular genus of Xestomyzinae, especially the North American species Henicomyia hubbardi.

We have some images of Henicomyia on iNat., but it would be great to see more, especially good images in focus. It is a genus that appears to be encountered rather infrequently, so keep your eyes out for this one. There are some great species in Central America that are undescribed, so it would be awesome to see some photos of these too.
Good hunting.

Images of Henicomyia so far: https://www.inaturalist.org/observations?place_id=any&taxon_id=248081

As the seasons swing again, the stiletto fly fauna switches back again. The spring genera are showing up, especially Ectinorhynchus in Australia and New Zealand and Entesia in Chile. Phycus brunneus seems to be a perennial favourite in India, although Irwiniella is sometimes seen and Thereva seemingly restricted to higher elevations. As we move into the summer months, we should start seeing more observations of Acraspisa, Parapsilocephala and Agapophytus in Australia, Peralia, Penniverpa and Notiothereva in Chile and Argentina, and Thereva, Schoutedenomyia and Caenophthalmus in South Africa; hopefully we will also see some more Phycusinae and Xestomyzinae throughout subsaharan Africa this season. Of course, a close relative of Peralia, Anabarhynchus will undoubtedly make frequent appearances this year throughout Australia, New Zealand and maybe even further afield in the Pacific.
Ozodiceromyia and Thereva continue to be frequently encountered in North America, and Thereva and Acrosathe common in Europe, although these genera with soon disappear for the winter months.

Looking forward to many new observations, observers and identifiers in the rest of 2023 and into 2024.

Get ready for lots of Thereva and Ozodiceromyia photos. These two genera have a lot of species and are relatively common in North America. In northern Europe and Asia you will see plenty of Thereva, but no Ozodiceromyia of course. Hopefully we will see some other interesting genera that we have seen before. With an estimated 1500-2000 species world wide, we can hope to see a lot more new species to add to our 300+ so far.

Also, with Autumn here, we might start to see some Autumnal stiletto flies in Australia (genus Medomega).

I don't know if it the community improving a lot, or the AI learning fast, but the genus identifications are really good over the past year, especially of common genera. This is great!

Please submit your photographs and comments about any aspects of stiletto fly behaviour and biology that you observe in the field. There is so much we still do not know about these flies. One interesting observation that is easy to see, is any evidence of swarming or lekking. We know this occurs in many species, but in different ways. From males hovering in swarms in backyard gardens (Ectinorhynchus spp.) to males sitting on a tree trunks and flying in a loop together and landing in the same place (Agapophytus pallidicornis, A. australasiae). We would love to see and hear about other examples you see in the field. Maybe add some images or videos too.

Congratulations all! We have reached 300 species of stiletto flies identified on iNaturalist. Hopefully we can reach 400 hundred soon.

With the southern hemisphere in action now, we are getting more species observed than ever. So many great images. We are up to 294 as of today. Looking forward to reaching a 300 milestone, which is approximately 1/4 of the total number of described species worldwide presently.

Well, it is spring in the Northern Hemisphere, and we are seeing the normal seasonality of observations swing back to the usual Thereva and Ozodiceromyia being the dominant stiletto flies being encountered in Europe and North America (Ozodiceromyia in the New World only though). We are starting to see the Southern Hemisphere observations starting to wane, which are typically dominated by Anabaryhnchus and Ectinorhynchus in Australasia, and Irwiniella in Asia and even Africa. Looking forward to seeing more tropical and Mediterranean species showing up this year, and we all have a wish list of the many genera still yet to be observed.

Shaun

Recently the number of accurate identifications from resident experts on Therevidae has begun to increase greatly. This is fantastic. Thanks to Chris Lambkin, Martin Hauser, Alberto Narro and Kevin Holston, to name a few, who have lent their expertise on this family of flies to put some authoritative species-level names on observations. The metadata on these records is amazing, with 'what', 'when' and 'where' data points allowing for the potential for important information in phenology and distribution of Therevidae species world-wide. The map is filling in nicely, especially for three genera (Anabarhynchus, Thereva and Ozodiceromyia). These are three of the five, most species-rich genera in the family and also the most encountered by far, especially in habitats where humans would encounter them (disturbed habitats like suburban areas in particular).This itself suggests something about these genera which is not found in other species-rich genera like Parapsilocpehala and Acraspisa, which are not encountered in any way close to the same level.
As more observations are uploaded and they are authoritatively identified, we will see even more patterns emerging, providing even more insights into the biology of this family. Also, given the number of new records, such as previously unknown sexes, and even undescribed species and genera being found for the first time, there is plenty more basic science to discover using this platform.

Please encourage others to join this project and contribute.

A remarkable bumble bee mimicking species of stiletto fly has been described in the journal Zootaxa. Named Sinothereva shangui Winterton, 2020, this amazing fly was discovered on iNaturalist from photographs by @mountainhome in Hebei Province, China. You can see the observations here: https://www.inaturalist.org/observations/25994973

The paper just published is here: https://www.mapress.com/j/zt/article/view/zootaxa.4816.3.6