The Diptera of Lesotho: a new Special Collection in African Invertebrates

While the insects of South Africa are well studied, Lesotho remains largely undersampled for flies.

Guest blog post by John Midgley and Burgert Muller

Despite centuries of study, our knowledge of the natural world is still woefully inadequate. This is especially true for inaccessible regions, but these regions often hold interesting species of communities to study. The best studied country in the Afrotropics is South Africa, but nearby countries have received much less attention.

Malaise trap over a stream at Sehlabathebe National Park.

The Kingdom of Lesotho is nestled within the borders of South Africa and this landlocked country shares many ecological similarities with its neighbour. However, Lesotho has an average altitude that is 900 m higher, leading to differences in its fauna and flora, especially in its alpine areas, as these are much more extensive than in South Africa.

View south-east from Moteng Pass in northern Lesotho.

While the insects of South Africa are well studied, in particular the True flies (Diptera), Lesotho remains largely undersampled for flies, and that in combination with its unique habitat has created an opportunity to contribute to the country’s biodiversity knowledge.

Malaise trap at Roma Trading post lodge. Even though the area is a modified garden site, Lesotho lacks basic biodiversity data and species were collected for the first time from Lesotho.

With discovery on their minds, Dipterists from four institutions (KwaZulu-Natal Museum, National Museum, Albany Museum and Royal Museum for Central Africa) planned to undertake several fieldtrips to Lesotho. The aim was not to just increase the holdings of the institutions, as this would be short-sighted. Instead, the goal was to promote conservation and to improve on the current knowledge on the Diptera of Lesotho. The rest is natural history, and the special collection on the Diptera of Lesotho in African Invertebrates was born.

Pristine grassland at Sehlabathebe National Park. Large parts of Lesotho are modified by agriculture, but in remote areas pristine sites remain.

Even areas that have received little attention are not complete blank slates, and a handful of expeditions to Lesotho were undertaken in the mid-20th Century, most notably by the Lund Zoological Institute, The KwaZulu-Natal Museum, The Durban Natural Science Museum and the Albany Museum, but large targeted and purposeful collections are not common. The specimens from these expeditions are housed at various international and local South African institutions, which do have some limited collections of Lesotho material.

Letšeng la Letsie is the largest alpine lake in Lesotho, but despite being a protected area is heavily influenced by grazing.

We added three further expeditions to this, in December 2021, November 2022 and January 2023, adding over 7000 specimens to the National Museum, Bloemfontein and KwaZulu-Natal Museum collections. The details of these specimens can be found in our recently published introduction to the Special Collection along with photographs of the collection sites from our expeditions.

New African Invertebrates issue celebrates the work of Dr Jason G. H. Londt

For more than 50 years, Londt has made a notable impact on South African and international entomology.

The latest issue published in African Invertebrates is a special one: it honours the career and achievements of South African entomologist Dr Jason G. H. Londt. In celebration of Londt’s prolific and inspiring work, the issue was published to coincide with his 80th birthday in 2023.

For more than 50 years, Londt has made a notable impact on South African and international entomology, collecting large numbers of Diptera and other insect orders. He has made outstanding contributions to the entomological research on flies, especially assassin or robber flies (Diptera, Asilidae), on hangingflies (Mecoptera, Bittacidae), and field collections of insects, primarily in South Africa.

Throughout his career, he has described more species of Afrotropical Asilidae and Bittacidae (Mecoptera) than any other author.

“Today, some 952 Asilidae species are recognised from southern Africa and thanks to Jason’s exceptional collecting efforts and detailed revisionary taxonomic publications these species can be easily identified,“ write African Invertebrates editors John Midgley and Torsten Dikow in the editorial to the Festschrift.

The Festschrift includes nine articles celebrating Dr Londt’s career by authors from three continents, covering the broad contributions that he has made to Afrotropical entomology. It also introduces five new species described in his honour, one hangingfly and four true flies.

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Chance record of an annual mass emergence of enigmatic mantis-flies

Being neither mantids nor flies, the peculiar mantis-flies are in fact predatory lacewings which use their mantis-like forelegs to catch prey. While most mantis-flies are known to feed on spider eggs in their immature stages, the larval lifestyle of one subfamily–the Drepanicinae–has remained a mystery.

That is until James Dorey, an accomplished insect photographer and student of entomology at the University of Queensland, encountered a mass emergence of rarely-seen adults in his father’s macadamia orchard in eastern Australia, as reported in the open access Biodiversity Data Journal.

Right before James’ eyes and camera, the pupae were coming out from under the ground to grasp hold of tree trunks and undergo the final moult to emerge as adults.

Not only did he take some beautiful photos of the insects, but he also managed to capture a stunning time-lapse video of the pupae moulting into the adult stage.

The young researcher then contacted his university lecturer, David Merritt, to find out more about the phenomenon he had encountered. Together, they approached experts on mantis-flies, including Trevor Lambkin who was able to identify the insects as belonging to the mystery group, whose immature stages have so long remained unknown.

James managed to obtain some eggs from a fertile female and observed them hatch to produce tiny larvae that were immediately photographed and described in detail for the first time in a scientific journal.

“It is likely that the immature stage of these mantis-flies’ life cycle takes place underground in moist or forested habitats, perhaps explaining why it has never been recorded before,” explain the authors.

Yet to answer is the question what the immature mantis-flies feed on: is it spider eggs just like their relatives or some other underground-dwelling insect or arachnid?

“Perhaps some digging around in the macadamia orchard at the right time of year will reveal the answer,” say the researchers.

James is currently at Flinders University in Adelaide, carrying out a genetic analysis of the diversification of Fiji’s native bees.

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Original source:

Dorey JB, Merritt DJ (2017) First observations on the life cycle and mass eclosion events in a mantis fly (Family Mantispidae) in the subfamily Drepanicinae. Biodiversity Data Journal 5: e21206. https://doi.org/10.3897/BDJ.5.e21206

Shadow-loving insect named after Tuomas Holopainen of Nightwish

Tuomas Holopainen, the multi-talented musician and founder of the symphonic metal band Nightwish, is also a full-blooded nature person. This gave conservation biologist Jukka Salmela of Metsähallitus Parks & Wildlife Finland an idea for the name of a new species he found in Finland. Discovered in eastern Lapland during an insect survey, the fungus gnat was given the scientific name Sciophila holopaineni after Tuomas. The new species is described in the open access Biodiversity Data Journal.

“I am very, very touched. This is the highest honour a nature nerd like me can receive,” Tuomas Holopainen replied after Jukka, who collected and described the fungus gnat, asked him for permission to name the species after him.

The idea for the name came up to Salmela while he was thinking about the habitat and appearance of the species. Then, he recalled Tuomas Holopainen’s interest in the natural sciences.

So far, the new species of fungus gnat has been only known from two locations: the Törmäoja Natura Area in Savukoski, eastern Lapland, and a meadow close to the White Sea, Russian Karelia.

The dark and beautiful gnat thrives in shadowy environments. In Törmäoja, it was caught in a river gulch next to the river source, while hiding under the shelter of the forest. Salmela proposes ‘tuomaanvarjokainen’ as the common Finnish name, inspired by the latest Nightwish album. After all, the themes of the album, Endless Forms Most Beautiful, are evolution and the diversity of nature.

Fungus gnats are flies, which feed on dead wood or fungi. Some of the larvae are predaceous. At current count, there are almost 800 species in Finland and about 1,000 in the Nordic countries. In fact, the Fennoscandia region is one of Europe’s biodiversity hotspots for this group of insects.

The Tuomas Holopainen’s species is only one of the eight new flies described in the study. Among them are the Boletina norokorpii fungus gnat, named after Docent Yrjö Norokorpi and known only from Ylitornio; Phronia reducta, which inhabits Salla and Siberia; and Orfelia boreoalpina found in Törmäoja and the German Alps.

The Parks & Wildlife Finland of Metsähallitus is responsible for the management and species surveys of the State’s nature reserves. The collected data is needed in activities such as assessing the status of biodiversity, the protection of species, and planning the management and use of the reserves. Insects are as good an indicator of the state of the natural environment as better-known vertebrates or plants. The diversity of insect species forms part of natural biodiversity and is necessary to human well-being.

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Original source:

Salmela J, Kolcsár L (2017) New and poorly known Palaearctic fungus gnats (Diptera, Sciaroidea). Biodiversity Data Journal 5: e11760. https://doi.org/10.3897/BDJ.5.e11760

Assassins on the rise: A new species and a new tribe of endemic South African robber flies

Discovery of a new species of assassin flies led to the redescription of its genus. This group of curious predatory flies live exclusively in South Africa, preferring relatively dry habitats. Following the revisit, authors Drs Jason Londt, KwaZulu-Natal Museum, South Africa, and Torsten Dikow, Smithsonian Institution National Museum of Natural History, USA, publish updated information about all species within the genus, now counting a total of seven species, and also establish a new tribe. Their study is published in the open access journal African Invertebrates.

The family of assassin flies (Asilidae), also known as robber flies, are curious insects, which have received their common name due to their extremely predatory behavior. The assassin flies prey on a great variety of insects, including beetles, moths, butterflies, wasps, other flies, as well as some spiders, as early as their juvenile stage of development. When hunting, they would ambush their prey and catch it in flight. Then, they would pierce the victim with a short and strong proboscis, while injecting venom. Once in the body of the prey, it quickly dissolves the insides, so that the assassin fly can suck them out.

The published study was spawned by the collection of new specimens of previously described assassin flies of the species Trichoura tankwa by the junior author in December 2015. These specimens could not be easily identified and so the authors started to look at all available specimens in natural history museums.

image-2The new species, called Trichoura pardeos, was discovered in Tierberg Nature Reserve by the authors in 2004, a small conservation area located on the north banks of the Gariep River in the Northern Cape province of South Africa. The habitat comprises almost entirely a large rocky hill, where the vegetation is scarce and dominated by drought-resistant plants, such as aloes. The fly is predominantly red-brown in colour, with silvery, white and yellowish markings.

Having noted morphological variation between the species inhabiting areas with differently timed yearly rainfalls, the entomologists suggest that two groups within the studied genus have adapted to these different patterns in western and eastern South Africa. They also expect that species representing Trichoura could be also dwelling in Namibia, Botswana, Mozambique and possibly Zimbabwe.

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Original source:

Londt J, Dikow T (2016) A review of the genus Trichoura Londt, 1994 with the description of a new species from the Northern Cape Province of South Africa and a key to world Willistonininae (Diptera, Asilidae). African Invertebrates 57 (2): 119-135. https://doi.org/10.3897/AfrInvertebr.57.10772

The city of angels and flies: 12 unknown scuttle fly species have been flying around L.A.

Although the second-largest and rather concrete metropolis in the United States might not be anywhere near one’s immediate association for a biodiversity hotspot, the fly fauna of Los Angeles is quite impressive. As part of BioSCAN, a project devoted to exploring the insect diversity in and around the city, a team of three entomologists report on their latest discovery – twelve new scuttle fly species. Their study is published in the open access Biodiversity Data Journal.

Launched in 2013, the Natural History Museum of Los Angeles County‘s project BioSCAN seems to never cease to amaze with large numbers of newly discovered species. The first phase of the study finished with 30 species of flies new to science from sites in 27 backyards, 1 community garden, the Los Angeles Ecovillage, and the Nature Gardens at the Museum. In recognition to the residents, who had literally let the scientists in their homes, each of those flies was named after the relevant site’s host.

When they decided to revisit the specimens they had collected during the first year of the project as well as older museum collections, the authors of the present paper were in fact quite certain they were about to find a new batch of unknown flies.

Img2 M. stoakesi

Having already described so many new scuttle fly species, the latest twelve had initially gone undercover, all being rare and often represented by only one specimen among the total of 43,651 collected individuals.

“The remarkable diversity of biologies of these flies makes them a varied and essential group to document in any ecosystem,” the entomologists explain.

The extensive BioSCAN project is still ongoing thanks to its passionate staff, international collaborators and advisors, as well as the large number of students and volunteers. Being especially grateful for their help, the scientists have named one of the fly species M. studentorum and another one – M. voluntariorum. The project is currently in its second phase of collecting.

“These volunteers are critical to our operation, and have contributed to everything from public outreach in the NHM Nature Lab to specialized work on phorid flies,” point out the authors.

In the end, the researchers hope that they will get their message across to other taxonomists, funding agencies, institutions and the public alike. Urban environments with their fast-changing conditions and biodiversity profile, need constant attention and scientific curiosity.

“There is an enormous taxonomic deficiency, including, or, perhaps, especially, in rapidly changing urban environments,” they say. “Taxonomists and their funding agencies must give time, attention and money to the environments surrounding their towns and cities.”Img3 M. wongae

“Baseline collections of urban fauna must be established in the present if there is hope for understanding the introductions and extinctions that will occur in the future,” they stress.

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Original source:

Hartop E, Brown B, Disney R (2016) Flies from L.A., The Sequel: A further twelve new species ofMegaselia (Diptera: Phoridae) from the BioSCAN Project in Los Angeles (California, USA).Biodiversity Data Journal 4: e7756. doi: 10.3897/BDJ.4.e7756

Surprising exotic flies in the backyard: New gnat species from Museum Koenig’s garden

Little did scientists Kai Heller and Björn Rulik expect to discover a new species in Germany’s Alexander Koenig Museum‘s garden upon placing a malaise trap for testing purposes. Not only did an unknown and strikingly coloured gnat get caught, but it turned out to be a species, which showed to have much more in common with its relatives from New Zealand. Their study is published in the open access Biodiversity Data Journal (BDJ).

While the genus, which the new dark-winged fungus gnat species belongs to, likely originates from the Australasian region, it was so far represented by only three species in Europe. None of them, however, stands out with the contrasting colouration of the presently announced fourth one.

The new gnat, called Ctenosciara alexanderkoenigi after the German museum’s founder, is described based on a single specimen caught in the framework of the German Barcode of Life Project (GBOL). Over three days, the scientists observed the flying insects getting caught in a malaise trap, placed among the predominantly non-native plants in the Alexander Koenig Museum’s garden. This tent-like structure is designed to catch flying insects. Once they fly into its walls, they get funnelled into a collecting bottle.

Upon noticing the beautiful striking colour of the fly, the two specialists were convinced they had just discovered a new to science species. Most of these flies are bright brownish, and the only other orange European dark-winged fungus gnat – almost uniformly orange. In contrast, the new species stands out with a mixture of reddish, black and yellowish-white hues. Based on the DNA-barcode match with New Zealand specimens, the authors concluded that the species must have arrived from the Australasian region in Europe quite recently.

oo_47399

“It is a rare occurrence, that a species from the opposite end of the world is represented by a single specimen only and it is not yet clear, whether Ctenosciara alexanderkoenigi has a permanent population in Germany or if it was only introduced casually with plants or soil,” they explain. “Probably, the species was recently introduced from the Australasian Region. If it was a permanent member of the European fauna, a striking species like this would likely have been found earlier.”

In conclusion, the scientists note that modern technologies such as the high quality photo documentation, established as a standard by the BOLD project, DNA barcodes assigned with BINs, as well as facilitated by speedy publishing, have largely aided taxonomists to build on the biodiversity knowledge.

“We believe that the rapid description of Ctenosciara alexanderkoenigi, coupled with the BDJ reviewing system, might be a robust and ground-breaking way to accelerate and stabilise taxonomy in the future,” they finish their paper.

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Original source:

Heller K & Rulik B (2016) Ctenosciara alexanderkoenigi sp. n. (Diptera: Sciaridae), an exotic invader in Germany? Biodiversity Data Journal 4: e6460. doi: 10.3897/BDJ.4.e6460