Jan Mertens

Thyreophagus berxi, a mite species new to science discovered in Belgium

text by Jonas Merckx


MiteFind, BINCO's mite workgroup, has discovered a new species for science in Belgium: Thyreophagus berxi. The different populations were discovered in Gentbrugge and Heverlee, but later also in France and Germany. The mites were found under the bark of slightly rotting fallen twigs of beech and birch trees, where T. berxi feeds on microorganisms. The female-only mite populations reproduce asexually and, under unfavourable conditions, can form phoretic deuteronymphs that hitch a ride on insects.

Thyreophagus berxi is named after the Belgian entomologist Peter Berx, known from the very popular Flemish podcast 'Nerdland Podcast'. Peter Berx promotes the search for invertebrates in and around our own gardens, a nice analogy with the discovery of T. berxi.

With the help of the mite taxonomist Pavel Klimov, T. berxi was described together with four other new Thyreophagus species: T. aisT. hobe, T. ojibwe, and T. potawatomorum. The detailed description and the new determination key can be found in the article:
Klimov PB, Kolesnikov VB, Demard EP, Stinson CS, Merckx J, Duarte MV, Pedroso LGA, Khaustov AA, Myers-Hansen JL, Wäkers FL & Vangansbeke D 2023. Going Asexual: A Survey of Mites of the Genus Thyreophagus (Acari: Acaridae) Revealing a Large Number of New Parthenogenetic Species in the Holarctic RegionLife, vol. 13, doi: 10.3390/life13112168.



MiteFind, de mijtenwerkgroep van BINCO heeft in België een nieuwe soort voor de wetenschap ontdekt: Thyreophagus berxi. De verschillende populaties zijn ontdekt in Gentbrugge en in Heverlee maar later ook in Frankrijk en Duitsland. De mijten werden gevonden onder de schors van licht rottende gevallen takjes van beuk en berkenbomen, waar T. berxi zich voedt met micro-organismen. De mijt is plant zich uitsluitend ongeslachtelijk voort en kan bij ongunstige condities foretische deuteronimfen vormen die meeliften op insecten.

Thyreophagus berxi is vernoemd naar de Belgische entomoloog Peter Berx, bekend van de zeer populaire Vlaamse podcast ‘Nerdland Podcast’. Peter Berx promoot de zoektocht naar invertebraten in en rond onze eigen tuin, een mooie analogie met de vondst van T. berxi.

Met behulp van de mijtentaxonoom Pavel Klimov werd T. berxi samen met vier andere nieuwe Thyreophagus soorten beschreven: T. aisT. hobe, T. ojibwe, en T. potawatomorum. De beschrijving en de nieuwe determinatiesleutel kan gevonden worden in onderstaand artikel:
Klimov PB, Kolesnikov VB, Demard EP, Stinson CS, Merckx J, Duarte MV, Pedroso LGA, Khaustov AA, Myers-Hansen JL, Wäkers FL & Vangansbeke D 2023. Going Asexual: A Survey of Mites of the Genus Thyreophagus (Acari: Acaridae) Revealing a Large Number of New Parthenogenetic Species in the Holarctic RegionLife, vol. 13, doi: 10.3390/life13112168.

Sky Islands and Spiders: a brief tale of two contrasting discoveries in southern Africa

text by BROGAN PETT @BroganConBio

I first got involved with BINCO through fieldwork in north-western Madagascar in 2017 surveying spiders in the enigmatic dry forests. From here on, I started working with Merlin and was very interested in the work that BINCO carries out, joining later in the year after my first Madagascar visit. I have so far visited the Madagascar field site twice. As well as an initial visit to the collection at the RMCA in Tervuren. I was invited on my second visit, onto the Xevioso project.

The two newly described species of Xevioso have a captivating appearance, the palps are certainly beautiful and incredibly intricate in their structure. I spent around two weeks in the lab at the RMCA on my second visit, with plenty of evening work sprinkled in, looking through each of the Mozambique pitfall samples and extracting all of the Xevioso material. There was a substantial sex bias in the collections in favour of males. Making female specimens eight-legged gold! In fact, we only found two females, which lends itself towards “conventional” sex roles in these spiders: the males are out searching for mates.

We had a lot of comparative material to work with; the types of the most closely related species and a few others in the genus really helped elucidate the key diagnostic features for me. Then there was three or so months of back and forth developing the manuscript with Rudy Jocqué (co-author and mentor), finessing the descriptions along the way (Pett & Jocqué, 2020)!

These two new species exhibit very interesting distributions. Xevioso cepfi, from the Njesi expedition, was found at each of the mountain plateaus, potentially suggesting its prevalence as a montane specialist. Contrastingly, the male holotype and female paratype of Xevioso megcummingae were collected in an urban garden in Harare, Zimbabwe. Following my museum visit, Rudy identified a much smaller male specimen of X. megcummingae whilst digging through material from Malawi. Its presence in the Viphya mountains (Malawi), a truly remarkable range expansion! This makes me guess it is present in a wide suite of areas in between its currently known distribution.

The discovery of Xevioso cepfi actually represents the second new spider discovery from the BINCO Njesi expedition, with Cicynethus mossambicus (see Jocqué & Henrard, 2018), also representing the most northerly limit of a species of its genus (as in X. cepfi). These results further augment the incredible value that such expeditions can have for biodiversity knowledge in poorly studied regions of the world.

The 2016 Njesi expedition was funded by the Critical Ecosystem Partnership Fund (CEPF). In honour of the fantastic work they do to help protect biodiversity and our natural capital in this world, we named X. cepfi after the organisation.



Jocqué R. & Henrard, A. (2018) A revision of the genus Cicynethus Simon, 1910 (Araneae, Zodariidae), a tale of colour patterns. European Journal of Taxonomy 465: 1–35.
Pett B.L. & Jocqué R. (2020) Description of two new species of Xevioso (Araneae: Phyxelididae) from Southern Africa, with the northernmost localities for the genus. European Journal of Taxonomy 636: 1–18.

Declining populations of threatened bird species along the Mekong River, Cambodia

text by Erik Sandvig @eriksandvigc
images by John Mittermeier @johnmittermeier

In May 2018, together with an interdisciplinary team of biologists put together by BINCO, we did a rapid biodiversity assessment along the central section of the Mekong River in Cambodia. The goal for John Mittermeier and I, the ornithologists of the team, was to determine the avian diversity in the study area, which had been proposed by WWF as a protected area for the critically endangered Hog Deer (Axis porcinus). Luckily for us, a previous survey of the area had been done in 2008 by Robert Timmins who had surveyed birds along the river near our study site over the course of several weeks. This work set the groundwork for us to compare how things might have changed over the last decade. Our findings from this expedition were recently published in BirdingASIA (volume 32: 80-89). Here we share some additional details about our findings and a brief behind the scenes of the expedition. For more detailed information, feel free to get in touch for a copy of the published article.

After a few days of preparations and logistics in Phnom Penh our group set out to Kracheh (also spelled Kratie), located on the central section of the Mekong River. The plan was to establish four base camps over the next three weeks, all not far from the river, focusing on four distinct types of habitat. These were: sandy riverine islands, wet grassland, dry Dipterocarp forest, and semi-evergreen forest. One of our primary goals was to establish the presence and relative abundance of species of conservation concern. Of particular interest in this area are the endangered ibises and vultures.

Motoring into the Mekong we reached the islands where we were to set up camp for the next three days. From Timmins’ survey we knew White-shouldered Ibis (Pseudibis davisoni) was possible here and our boat driver assured us they were seen sporadically in some big trees in the river. Over the next days we covered the innumerable branches of the river separating the small islands in search of them, spotting a group of 7 on one day, and 5 another. A good sign to at least confirm their continued presence in the area. Of note was also finding the fourth record of Green-backed Flycatcher (Ficedula elisae) for Cambodia in the dense forest of one of the islands.

However, we also got our first glimpse of the direct threats that birds are facing along the Mekong at this first site. Exploring one of the islands we stumbled upon a couple of boys digging into a sandbank. Approaching them, they proudly showed us their bounty; eggs and nestlings of Blue-tailed Bee-eaters (Merops philippinus), apparently a local delicacy.

Our second camp was located just west of the river, in an area with wet grasslands and patches of dipterocarp woodland, where Hog Deer had been sighted some time back. In regard to birdlife, the area looks quite disturbed. So, we weren’t expecting much when we happened upon a skulking Acrocephalus warbler in the long grasses. After a challenging photo-op, John managed to take some half-decent pictures, confirming the ID as a White-browed (Manchurian) Reed Warbler (Acrocephalus tangorum). In total we saw at least four individuals in the area. Classified as Vulnerable, with only one known wintering area around Tonle Sap (much further west) in Cambodia, this record, close to the second camp, comprises a new wintering ground for the species.

The third camp was located on a large river island about 40km north of our previous camps. The habitat was mostly semi-evergreen forest, with good quality dry dipterocarp forest a short boat ride away on the other side of the river. The local WWF team had been running a ‘vulture restaurant’ in this dipterocarp forest for some years, in hopes of aiding the diminishing populations of Red-headed (Sarcogyps calvus), White-rumped (Gyps bengalensis) and Slender-billed Vultures (Gyps tenuirostris). These species are all Critically Endangered, so we were keenly interested in assessing their continued presence since Timmins’ survey in 2008. The team arranged for a cow to be set out in a clearing about a week before we arrived, and a local man, employed by WWF, kept close tabs on the carcass in case any vultures arrived. None came. We later learned that it had been many months since any had been seen, despite their efforts in placing a fresh carcass out every month. Although this doesn’t necessarily mean they are completely gone, it does paint a very worrying picture for these species.

While at this camp we also made a couple boat trips up the Mekong to a river island with breeding River Terns (Sterna aurantia), a species that is now highly threatened in Southeast Asia, where two tern nests were being monitored by a local couple employed by WWF and WCS. Unfortunately, predation by rats is a real problem on these small islands and one of the tern nests failed shortly after our visit. But not all was doom and gloom, as on one of the visits we recorded a couple greenshanks on a sandbank. Upon later inspection we were able to identify one of them as a Spotted (Nordmann’s) Greenshank (Tringa guttifer) – the first record for interior Cambodia. This finding provides evidence that the Mekong could be an important north-south corridor for this migratory species.

Now starting the third week of the expedition, we established our last camp in semi-evergreen forest in an area protected by the local village west of our last camp. Before even arriving at the spot we were struck by the widespread clearing of the forest in the area. Not far from the camp, commercial loggers were bulldozing roads into the forest. Perhaps one of the most haunting memories of the trip comes from these forests, when John and I spotted a pair of Great Hornbills (Buceros bicornis) displaying in a large tree. We were awe-struck by these majestic birds, rolling their heads back and making their guttural calls, but our heart sank hearing chainsaws roaring nearby.

After three weeks of surveying we were able to record 219 species in these four habitats, more than a third of the total species known from Cambodia. Among these were four globally threatened and eleven near threatened bird species. Worryingly, we did not find several species of waterbirds that had been recorded by Timmins in 2008 and we never saw any of the threatened vultures despite the feeding efforts of local conservationists. This suggests continued population declines of several of these birds along the Mekong. But heart-lifting news came after the expedition when the Cambodian government announced that the areas we had surveyed will be established as two new protected areas. More recently, more reassuring announcements were made including the government scrapping plans to build damn on the Mekong, close to the Laos border. These developments provide a glimmer of hope that the species recorded during the expedition will continue to persist in this area, and that those absent may one day return.

MyrmEcoDex, BINCO's ant work group, studies the ant diversity of Cusuco NP

text and images by MATT HAMER @entohamer


Cloud forests are some of the most biodiverse ecosystems on the planet, being sites of high endemism that are heavily threatened from human-caused pressures. Cusuco National Park (CNP), located in Honduras, is no exception. The park holds considerable biodiversity and has been designated as one of the 137 irreplaceable protected areas in the world (Le Saout et al., 2013). Cusuco was allocated protection after a sweeping decree issued by the Honduran Government in 1987 that gave all mountainous habitats above 1800 m protection. In reality, however, the park is heavily threatened by illegal logging, deforestation and encroaching agriculture. 

Relatively little is known of the insect biodiversity of CNP, particularly the ant (Formicidae) diversity. Ants are an ecologically dominant group, comprising of species scattered throughout the food web from herbivorous leaf-cutting ants (Fig 1) to the highly predaceous army ants (Fig 2) that consume huge numbers of arthropods and vertebrates on the forest floor. Ants are also fantastic indicators of habitat change because many species are highly sensitive to ecological alterations allowing for the study of fine scale diversity and community patterns throughout an ecosystem (Underwood and Fisher, 2006; Tiede et al., 2017; Lessard, 2019). It is therefore important to document this rich community and the impact of occurring human-associated pressures.

MyrmEcoDex, the ant work group of BINCO, investigates the ant diversity present in CNP using inventories from previous expeditions to the park, alongside museum reference specimens and further sampling in collaboration with Operation Wallacea. Five members, based in Belgium, are currently involved in mounting, identifying, and databasing of the specimens. At this time, the team has prepared 251 specimens on point mounts and identified the majority of these, at least eight of them being new to the park already. These samples originate from opportunistic sampling by MyrmEcoDex volunteers in 2018 and 2019 and are also collected from pitfall samples from by-catch during dung beetle monitoring surveys conducted by Operation Wallacea. 

Ants occupy a variety of habitats throughout CNP and so multiple collecting methods will be needed to sample their biodiversity effectively. A significant number of species occupy the leaf-litter layer between the soil and vegetation - this diversity has previously been explored by the LLAMA project in 2010 (Longino et al., 2014). However, further surveys in areas not sampled by the LLAMA project may reveal new records and potentially new species. Additionally, it will be interesting to document whether ants found during the LLAMA project are recovered during current survey work. Ants also reside above ground where particular species dominate over others; it can be easy to overlook more subtle and secretive species, therefore methods such as bait-trapping together with more extensive pitfall trapping could be used to broaden our knowledge on ant diversity. 

MyrmEcoDex hopes that this initial survey work will galvanise further ant surveys in other remote and threatened parts of the world allowing for the inventories of these ecological important organisms and help to understand and document the impacts of anthropogenic pressures.



Lessard, J. P. (2019) ‘Ant community response to disturbance: A global synthesis’, Journal of Animal Ecology, 88(3), pp. 346–349. doi: 10.1111/1365-2656.12958.
Longino, J. T., Branstetter, M. G. and Colwell, R. K. (2014) ‘How ants drop out: Ant abundance on tropical mountains’, PLoS ONE, 9(8). doi: 10.1371/journal.pone.0104030.
Le Saout, S. et al. (2013) ‘Protected areas and effective biodiversity conservation’, Science, 342(6160), pp. 803–805. doi: 10.1126/science.1239268.
Tiede, Y. et al. (2017) ‘Ants as indicators of environmental change and ecosystem processes’, Ecological Indicators. Elsevier Ltd, 83, pp. 527–537. doi: 10.1016/j.ecolind.2017.01.029.
Underwood, E. C. and Fisher, B. L. (2006) ‘The role of ants in conservation monitoring: If, when, and how’, Biological Conservation, 132(2), pp. 166–182. doi: 10.1016/j.biocon.2006.03.022.

Checklist of the leaf beetles (Coleoptera: Chrysomelidae) from El Salvador

Leaf beetles are a diverse and economic significant group. Many species from this family are pest species on crops. Identification is challenging and the knowledge about distribution of leaf beetles is limited in many areas, especially the tropics. Logistic and administrative challenges in many countries make it difficult to organise a sampling campaign. Historic collections from museums are a valuable starting point to assess species diversity in a certain region.

BINCO discovered a big collection of leaf beetles from El Salvador in the Royal Belgian Institute of Natural Sciences (RBINS) in Brussels. This collection was originally from Jan Bechyné, a known scientists who did much research on this family of beetles. Bechyné lived from 1920-1973 and after getting his PhD in 1948, he worked in several institutes including the natural history museum of Prague, the museum G. Frey and the RBINS. In 1959, he went to Central and South America with his wife Bohumila, where he worked and lived in El Salvador and eventually settled in Venezuela. Together with his wife, he wrote 188 publications on leaf beetles which are still very relevant.  The collection of Bechyné in the RBINS consists of 18 well filled insect boxes and was digitised by BINCO during June – September 2017. In total, 2.797 specimens belonging to 89 species were present. The information extracted from this collection together with data from literature was compiled in a checklist of leaf beetles from El Salvador.

At this moment, 420 species of leaf beetles (Chrysomelidae) are recorded from El Salvador. This project added 33 species to the list. This study will serve as a baseline for further research in the area of Central-American leaf beetles.

The results of our study were published in the scientific journal ZooKeys and can be found here.

Distribution and identification of cereal leaf beetles in Flanders

Cereal leaf beetles, a genus of leaf beetles (Coleoptera: Chrysomelidae – Oulema spp.) are known pest species of cereals in the Northern hemisphere. Due to very small differences in morphology, accurate identification of the species within this genus is still a challenge. Moreover, since these species exhibit a different phenology and thus the date of control practices is dependent on the dominant species, it is important to know what species make up most of the population. By this, more selective control strategies can be developed in the future without using too much pesticides.

BINCO collaborated with a study on the distribution and species diversity of cereal leaf beetles in Flanders. The species diversity was monitored in several cereal fields during three executive years. We found three species of Oulema which were frequently present; O. melanopus, O. duftschmidi and O. obscura. By the use of discriminant analysis, we found that these species can be identified quite reliably by body shape (like length and width of elytra), but checking the identifications by use of genital structures is still advisable.

Population densities were very variable within and between years, which could hamper selective control strategies. This would require an adequately big and spatially and temporally spread sampling campaign.

The results of this project were published in the scientific journal Environmental Entomology and can be found here.

Photo: Hilde Christiaens, this project was funded by VLAIO-LA

Book: Orchids of the Maltese Islands - a descriptive guide

Since 2016, BINCO and Greenhouse Malta NGO initiated the Malta Biodiversity Initiative (MABIMO). MABIMO strives towards a biodiversity monitoring network for biodiversity across the Maltese islands with standardised survey protocols. This network will help to gather the necessary information to assess what species are present, how they are distributed and detect possible trends in time and space to better conserve the respective taxa and ecosystems.

MABIMO is initiated with a select number of taxonomic groups including orchids. BINCO and Greenhouse mobilize volunteers through citizen science projects to collect information on orchid data to gain insight in their current distribution across the islands and help construct and update the red list of threatened species for Malta.

The book ‘Orchids of the Maltese Islands - a descriptive guide’, written by Stephen Mifsud in collaboration with Greenhouse Malta and BINCO, is a product from this citizen science project and can be considered a valuable addition to the current knowledge on Maltese orchids. The field guide covers all species of orchids known to occur on the Maltese Islands. Besides detailed morphological descriptions and identification keys illustrated with diagnostic photographs, the species pages in the book contain information on their distribution, rarity, morphological variation, flowering period, pollinators and so on.

“Orchids of the Maltese Islands” is a must have guide for nature enthusiast and professionals alike for anybody living in or visiting the Maltese islands.

The book is available online at NHBS and BDL amongst others.


During the second half of 2014, we studied the effect of the intensification of natural forest for coffee production on large mammal communities using camera traps in Ethiopia. Now the results are out and published in the conservation journal Oryx (see below).

The high demand for coffee internationally results in an ongoing intensification of natural forests by clearing understory and removing trees resulting in few undisturbed forest left in Ethiopia. Although overall species diversity remained constant, large and medium sized carnivores are the first to disappear and diurnal activity patterns are shifted to nocturnal. The increased accessibility of coffee forests decreases the diurnal activity of large mammals and specifically affects the top predators in the ecosystem.

This is the first study in Africa that studied large mammals in coffee forest. Although Ethiopia is known for its high number of both animal and plant species that do not live anywhere else in the world, there is a concerning lack of conservation activities to preserve the biodiversity locally. Moreover, the extent of agricultural land is rapidly increasing at the expense of natural forest, resulting in a significant loss in biodiversity. Coffee forest, however, has since long been proposed as a more sustainable agricultural system, conserving biodiversity while providing income for local communities. We found a mammal diversity in coffee forest comparable to that of mature natural forest. This study therefore indicates the importance of coffee forest in Ethiopia for mammal conservation, where coffee has been cultivated as a shade crop for more than 1,000 years.

However, this study also showed that large carnivores such as leopard and African civet had a tendency towards natural forest, while crested porcupine and Ethiopian hare were typically associated with coffee forest. The latter two species are not commonly associated with forest, so their presence in coffee forest may be related to increased forest accessibility and a well-developed herb layer in coffee forest compared to natural forest. Moreover, mammal activity in natural forest peaked during daytime whereas the activity pattern in coffee forest  was predominantly crepuscular and nocturnal. This may be a direct adaptation to frequent human disturbance. Both forest buffalo and leopard, for example, were only observed at night in coffee forest. This study therefore also shows that, despite the high mammal diversity in coffee forest, it is important to recognise it cannot fully replace natural forest as a habitat for large mammals.

The complete loss of natural forest in combination with increased human disturbances may result in the local extinction of top predators such as leopard, which can subsequently trigger negative effects on other forest components such as decreased forest restoration due to higher pressure of herbivores. Therefore, a balanced landscape mosaic of coffee and natural forest may be a valuable conservation option, contributing to local economy while safeguarding the diversity of large mammals.

We compiled a video showcasing a handful of the inhabitants of the study area.

If you would like to read more about this study, the paper ‘From natural forest to coffee agroforest: implications for large mammal communities in the Ethiopian highlands’ is now freely available until 31/12/2018 in Oryx—The International Journal of Conservation. The study was funded by the Rufford Foundation and Idea Wild.