Tag: fly

Houseflies and Blowflies – Not Bees – Are Among South Africa’s Best Mango Pollinators, But Climate Change Threatens Future Harvests

Study introduces a new way to measure pollinator “effectiveness,” not just presence, revealing that climate change could shrink suitable habitat for key mango pollinators by more than 40% in coming decades

Some of the most important pollinators for South Africa’s mango industry aren’t bees at all – they’re houseflies and blowflies, according to a recently published study in Frontiers of Biogeography by scientists at University College London (UCL).

The study, led by Matthew Phillips Sánchez and Richard Pearson of UCL’s Centre for Biodiversity and Environment Research, set out to find not just which insects visit mango flowers, but which ones actually pollinate them effectively.

Table of Contents

Not all visitors are pollinators

Visiting vs. pollinating species of mango in South Africa. Insect visitors of mango in South Africa (61), composed of five orders and 15 families (‘Visitors’). Compiled from global studies describing visitors to mango flowers, which are also present in South Africa with at least 20 occurrence records on GBIF. Thirty-eight of these are pollinators (pollen deposition effectiveness > 0), belonging to two orders and eight families (‘Pollinators’). Credit to Sánchez and Pearson, 2026.

Mango flowers attract a huge range of insect visitors, but many never touch the flower’s reproductive parts and so transfer no pollen at all. To separate the true pollinators from the freeloaders, the researchers used a Pollen Deposition Effectiveness (PDE) metric, which combines how often a species visits mango flowers, how often those visits make contact with the flower’s reproductive organs, and how much pollen is deposited per visit.

illustrative graphic on mango pollination size
Graphic credit to Matthew Phillips Sánchez, 2026.

Applying this method to 61 known mango-visiting insect species found in South Africa, the team identified 38 true pollinators – and found that flies, not bees, were the amongst the more effective pollinators. Blowflies (family Calliphoridae), the housefly (Musca domestica), and a tiny stingless bee species, Liotrigona bottegoi, ranked as the most effective pollinators identified in the study. Larger insects such as honeybees and carpenter bees (Xylocopa) were generally less effective per visit, likely because their bigger bodies make less consistent contact with the small mango flower’s reproductive structures.

Insects from the orders Lepidoptera (butterflies and moths), Coleoptera (beetles) and Hemiptera (true bugs) were found not to contribute meaningfully to pollination, either because they don’t make contact with the flower’s reproductive parts or because there wasn’t enough data to assess them.

A shrinking future for mango pollinators

The researchers combined their pollinator effectiveness data with species distribution models, statistical tools that predict where a species can survive based on climate, to project how pollinator habitat in South Africa’s main mango-growing provinces (Limpopo, Mpumalanga and KwaZulu-Natal) might change under future climate scenarios.

The results point to widespread declines. On average, pollinator species are projected to lose 42% (under a moderate-emissions scenario) to 43% (under a high-emissions scenario) of their currently suitable habitat by 2061-2080 or 66,663 km2 and 73,608 km2 respectively.

Mango pollinator species richness and potential pollination provision. Species richness and potential pollinator provision under present-day climate (left column) and SDM-predicted changes under two climate change scenarios (right columns). Credit to Sánchez and Pearson, 2026.

Flies were projected to be hit hardest, while some bee species were projected to gain ground in parts of the region. The study also found that pollinator communities are likely to undergo substantial species turnover, with many current pollinators potentially shifting toward the country’s south as the climate changes.

Encouragingly, the researchers found that potential pollination service didn’t decline much faster than pollinator numbers overall – a sign of what ecologists call “functional redundancy,” where many species contribute moderate pollination value rather than the community depending on one or two irreplaceable species. This suggests the loss of some species is less likely to cause a sudden pollination collapse, provided enough functionally similar species remain.

The mango industry

mangoes on a tree
Tomy mangoes by alexanruiz via Envato.

Mango is a significant industry in South Africa, valued at more than US$25 million annually and supporting over 13,000 jobs in processing and related trades, in addition to many smallholder and subsistence growers who rely heavily on wild, unmanaged pollinators.

The authors stress that their study is intended primarily as a proof-of-concept for this new modeling approach, rather than a definitive forecast of mango production. The models estimate climatically suitable habitat, not realised populations, and do not account for land use, habitat availability, or the timing of mango flowering relative to pollinator activity.

Practical steps for growers

pile of mangoes
Pile of Fresh Mangoes by elxeneize via Envato.

The researchers highlight several low-cost conservation measures that could help support wild pollinator populations in mango orchards, including reducing pesticide and herbicide use, setting up low-cost “stink stations” to attract pollinating blowflies, planting native flowering plants or allowing wildflowers to grow between orchard rows to provide food and nesting sites for pollinators, and increasing overall plant diversity within orchards.

Original source: 

Sánchez MP, Pearson R (2026) Biogeography of pollination under climate change: integrating pollinator effectiveness into species distribution models for mango in South Africa. Frontiers of Biogeography 19: e180771. https://doi.org/10.21425/fob.19.180771 

New ‘big-armed fly’ species named after former California governor Arnold Schwarzenegger

New species can be named for all types of attributes, but Natural History Museum of Los Angeles County entomologist Brian Brown knew exactly what name to give a bizarre new fly species he discovered in the Brazilian Amazon.

“As soon as I saw those bulging legs, I knew I had to name this one after Arnold,” says Brown. “Not only is he a major cultural icon and an important person in the political realm, his autobiography gave me some hope that I could improve my body as a skinny teenager.” For these reasons, Brown says, the former governor deserves to have the new fly named in his honor.

His research article is published in the open access Biodiversity Data Journal.

The fly is impressive in other ways, Brown explains. “It is known only from one female specimen that we almost overlooked because it is so incredibly small.”

In fact, it is the world’s smallest known fly, according to Brown, who should know, since he had previously described what was formerly the world’s smallest fly, at 0.400 mm in body length. The new fly, named Megapropodiphora arnoldi, is just a fraction smaller, coming in at 0.395 mm.

MegapropodiphoraHowever, unlike the enlarged forelegs that prompted the naming, the mid- and hind legs appear to be highly reduced, and the wings reduced to tiny stubs.

Even though the fly has not been observed in the wild, Brown concludes that it is clearly a parasitoid, probably of ants or termites, based on its pointed, sharp ovipositor. He further speculates that these flies probably grab onto the hosts and “hold on for dear life” until they reach a nest or colony where they can parasitize their victims more effectively.

Brown has had considerable success finding new species of tiny flies, which he says are “the continuing frontier for insect discovery.”

Some of the more obvious, larger insects might have already been described, but by looking at smaller specimens, especially from remote, tropical sites, the entomologist finds that almost everything is new.

Even in his home city of Los Angeles, Brown and collaborators found that almost half of the phorid flies were previously unknown.

For example, it was last year that they finally figured why a secretive fly had been observed around mushrooms with no clear explanation for nearly 30 years. The revelation occurred when L.A. Bed & Breakfast owners Patsy Carter and Lisa Carter-Davis decided to alert entomologists about a phenomenon happening in their yard.

Back in 2016, Brian and his team described at once a total of twelve scuttle fly species new to science after ‘field’ trips in the backyards of houses around the city of angels.

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Original source:

Citation: Brown B (2018) A second contender for “world’s smallest fly” (Diptera: Phoridae). Biodiversity Data Journal 6: e22396. https://doi.org/10.3897/BDJ.6.e22396

The tip of an iceberg: Four new fungus gnat species from the Scandinavian north

One may think that the extreme north of Europe is low in insect life, except for the notorious blood-sucking flies. However, while it is a generally accepted truth that both plant and animal species’ count is higher the closer one gets to the Equator, some insects display anomalous diversity gradient. Such is the case for European fungus gnats, for example, a highly diverse group of true flies. No less than about 1000 species are known to occur in the Scandinavian Peninsula, representing about 83% of the continent’s total. Furthermore, undescribed fly species are continuously being discovered from North Europe.

In a recent paper published in Biodiversity Data Journal, four new species are described. These species have been collected from mires and old-growth forests of Finnish Lapland between 2012 and 2014. One of the species has a wider range, known from Sweden, Norway and Canada.

‘I must admit that it was a pleasure to give names to these species’ says Dr. Jukka Salmela, conservation biologist at Parks & Wildlife Finland (Metsahallitus). ‘These four species are really interesting, because they are rather distant to other known members of the genus Boletina. I am also confident that these species are very rare and may be dependent on old-growth forests or small water bodies such as springs and wetlands.’

The names of the new species all reflect northern nature in one way or another. Boletina valteri is named after Professor Valter Keltikangas, a forest researcher who made very demanding and physically tough field excursions to Finnish Lapland in the 1920’s and the ’30’s.

Boletina kullervoi derives from Kalevala, a Finnish national epic. It tells the story of an orphan, called Kullervo, who eventually kills his foster father and commits suicide. The violent story of Kullervo has also inspired composer Jean Sibelius for his first symphony, “Kullervo”.

Boletina hyperborea is self-explanatory, meaning far north. The species occurs in Yukon and in northern Scandinavia. Similarly, Boletina nuortti is named after the River Nuortti. In north Sami language nuorti means east. The gorgeous and wild River Nuortti flows from Finland to Russia.

No less than 100 Fennoscandian (Scandinavian) fungus gnat species await their formal description. ‘The boreal and Arctic nature still holds many secrets. Entomologists with simple gear such as sweep nets, Malaise traps and microscopes can still make notable discoveries even in rather well-studied regions such as Finland and Sweden. Samples collected from northern mires and boreal forests are never boring if one studies neglected groups such as small flies,’ says Jukka Salmela. “These four newly described taxa just represent a small fraction of the numerous undescribed northern fly species, so they are like a tip of an iceberg.”

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Original source:

Salmela J, Suuronen A, Kaunisto K (2016) New and poorly known Holarctic species of Boletina Staeger, 1840 (Diptera, Mycetophilidae). Biodiversity Data Journal 4: e7218. doi:10.3897/BDJ.4.e7218

 

Novel cybercatalog of flower-loving flies suggests the digital future of taxonomy

Charting Earth’s biodiversity is the goal of taxonomy and to do so the scientists need to create an extensive citation network based on several hundred million pages of scientific literature. By providing a novel taxonomic ‘cybercatalog’ of southern African flower-loving (apiocerid) flies, Drs. Torsten Dikow and Donat Agosti demonstrate how the network of taxonomic knowledge can be made available through links provided to online data providers. Their work is available in the open-access Biodiversity Data Journal.

The present research showcases that the information cannot only be made available to the reader who follows the links, but also to machines that use the growing number of digital, online resources that are linked through persistent identifiers.

Primary data providers for taxonomic information such as species names (ZooBank), specimen images (Morphbank), species descriptions (Plazi), and digitized literature (BHL, Biodiversity Heritage Library; BioStor; and BLR, Biodiversity Literature Repository) play an important role in making data on species available in electronic form. Aggregators such as the Global Biodiversity Information Facility (GBIF) and the Encyclopedia of Life (EoL) gather this information automatically to distribute it even further to audiences beyond the reach of the life sciences.

In contrast to previous species catalogs, in cybercatalogs access to information is provided through links to open-access, online data repositories such as the ones listed above. Taxonomists and other users can now access this literature, species descriptions, and specimen records immediately without a search in a natural history library or collection. The cybercatalog takes advantage of a new publishing platform within the Biodiversity Data Journal that makes it easy to upload species information and links to data about these species through a CheckList template. Furthermore, the Biodiversity Data Journal now allows future updates and re-publications of the cybercatalog with the new unique persistent identifier (DOI, Digital Object Identifier) whenever a new species is described or other taxonomic changes take place.

The authors argue that cybercatalogs are indeed the future of taxonomic catalogs since the online data in them are easily accessible to anyone.

“It is a taxonomist’s dream to have online access to all previously published information on a species and through this step the discipline of taxonomy can (re-)position itself as a central resource within the life sciences and beyond to the public and society at large,” add the authors. “Online access will also help to narrow the gap between the South and the North as a fantastic example of unhindered access to our knowledge of the global biological diversity, which is increasingly under pressure from human populations.”

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For the realization of this project Plazi and Pensoft were partially supported by the EC-FP7 EU BON project (ENV 30845) (Building the European Biodiversity Observation Network).

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Original source:

Dikow T, Agosti D (2015) Utilizing online resources for taxonomy: a cybercatalog of Afrotropical apiocerid flies (Insecta: Diptera: Apioceridae). Biodiversity Data Journal 3: e5707. doi: 10.3897/BDJ.3.e5707

One new fly species, zero dead bodies: First insect description solely from photographs

The importance of collecting dead specimens or not when verifying a new species has been a hot ongoing discussion for quite a while now. Amid voiced opinions ranging from specimen collection being “no longer required” to relying on anything but physical evidence being defined as mere “malpractice,” science is now witnessing the first description of an insect species based solely on high-resolution photographs.

The unequivocally new bee fly species belongs to an extremely rare genus and was described by Drs. Stephen A. Marshall from the University of Guelph, Canada, and Neal Evenhuis from the Bishop Museum, Hawaii. Their research along with their commentary on the controversial topic are published in the open-access journal ZooKeys.

The authors in no way denounce dead specimen collection and dissection and even speak of it as the “gold standard” in new species description, they stress the fact that given the continued increased difficulty in obtaining permits to collect in many areas, and the resulting low probability of collecting and preserving specimens, there ought to be an alternative.

The newly described bee fly species, called Marleyimyia xylocopae, is a huge fly with a remarkable resemblance to a co-occurring carpenter bee. The new species might be a parasite of the bee, but not much is known about its behaviour. Therefore, the scientists stress that more observations are needed, something that will be encouraged by the availability of a name and an associated image.

Speaking of their own experience while studying their presently described new species, the scientists point out that relying on several high-resolution photographs has not only increased their knowledge of the biodiversity of the area and the genus, but has also provided some “interesting ecological and biological information”.

“As these image collections become curated just as dead specimens are curated today, the digital specimens will find their way into the work of practicing taxonomists, and they will need names,” the team explained. “It is unrealistic to think that distinct and diagnosable new taxa known only from good photographs and appropriate associated metadata should be organized and referred to only as “undescribed species” when they can and should be organized and named using the existing rules of nomenclature.”

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Original source:

Marshall SA, Evenhuis NL (2015) New species without dead bodies: a case for photo-based descriptions, illustrated by a striking new species of Marleyimyia Hesse (Diptera, Bombyliidae) from South Africa. ZooKeys 525: 117-127. doi: 10.3897/zookeys.525.6143