Royal Museum for Central Africa

Two fruit fly (Diptera: Tephritidae) species of economic importance: Ceratitis rosa Karsch and Ceratitis quilicii De Meyer, Mwatawala & Virgilio are present in South Africa. The two species were considered as one species prior to 2016, but were subsequently separated. In this study, the distribution and abundance of the two species were quantified in seven provinces in South Africa through trapping with Enriched Ginger Oil as an attractant. Trapping was conducted over three seasons across two years (2020 and 2021): late summer, autumn-winter, and spring-early summer. Host ranges of the two species were investigated by fruit sampling in and outside of trapping sites. Ceratitis quilicii was more widely distributed than C. rosa with the latter being recorded in only three north-eastern provinces. There were geographical limits for both species with no records of them in Northern Cape Province. Catches of C. quilicii were higher in summer with average temperatures varying from 15 to 27°C while for C. rosa, catches remained low and consistent between seasons. Ceratitis quilicii catches decreased at lower rates than those of C. rosa at temperatures below 15°C. The two species were reared from 13 plant species from nine families. Four of these hosts were infested by both C. quilicii and C. rosa in the same province where they occurred. Preferred hosts of the two species belonged to the Myrtaceae family. The characterisation of the distribution, abundance and host ranges of these pests will provide a baseline for pest status determination and implementation of management actions.

In the tropics, more precisely in equatorial dense rainforest, xylogenesis is driven by a little distinct climatological seasonality, and many tropical trees do not show clear growth rings. This makes retrospective analyses and modeling of future tree performance difficult. This research investigates the presence, the distinctness, and the periodicity of growth ring for dominant tree species in two semi-deciduous rainforests, which contrast in terms of precipitation dynamics. Eighteen tree species common to both forests were investigated. We used the cambial marking technique and then verified the presence and periodicity of growth-ring boundaries in the wood produced between pinning and collection by microscopic and macroscopic observation. The study showed that all eighteen species can form visible growth rings in both sites. However, the periodicity of ring formation varied significantly within and between species, and within sites. Trees from the site with clearly defined dry season had a higher likelihood to form periodical growth rings compared to those from the site where rainfall seasonality is less pronounced. The distinctness of the formed rings however did not show a site dependency. Periodical growth-ring formation was more likely in fast-growing trees. Furthermore, improvements can be made by a detailed study of the cambial activity through microcores taken at high temporal resolution, to get insight on the phenology of the lateral meristem.

Background Snail-borne trematodes afflict humans, livestock, and wildlife. Recognizing their zoonotic potential and possible hybridization, a One Health approach is essential for effective control. Given the dearth of knowledge on African trematodes, this study aimed to map snail and trematode diversity, focusing on (i) characterizing gastropod snail species and their trematode parasites, (ii) determining infection rates of snail species as intermediate hosts for medically, veterinary, and ecologically significant trematodes, and (iii) comparing their diversity across endemic regions. Methods A cross-sectional study conducted in 2021 in Chiredzi and Wedza districts in Zimbabwe, known for high human schistosomiasis prevalence, involved malacological surveys at 56 sites. Trematode infections in snails were detected through shedding experiments and multiplex rapid diagnostic polymerase chain reactions (RD-PCRs). Morphological and molecular analyses were employed to identify snail and trematode species. Results Among 3209 collected snail specimens, 11 species were identified, including schistosome and fasciolid competent snail species. We report for the first time the invasive exotic snail Tarebia granifera in Zimbabwe, which was highly abundant, mainly in Chiredzi, occurring at 29 out of 35 sites. Shedding experiments on 1303 snails revealed a 2.24% infection rate, with 15 trematode species identified through molecular genotyping. Five species were exclusive to Chiredzi: Bolbophorus sp., Schistosoma mansoni, Schistosoma mattheei, Calicophoron sp., and Uvulifer sp. Eight were exclusive to Wedza, including Trichobilharzia sp., Stephanoprora amurensis, Spirorchid sp., and Echinostoma sp. as well as an unidentified species of the Plagiorchioidea superfamily. One species, Tylodelphys mashonensis, was common to both regions. The RD-PCR screening of 976 non-shedding snails indicated a 35.7% trematode infection rate, including the presence of schistosomes (1.1%) Fasciola nyanzae (0.6%). In Chiredzi, Radix natalensis had the highest trematode infection prevalence (33.3%), while in Wedza, R. natalensis (55.4%) and Bulinus tropicus (53.2%) had the highest infection prevalence. Conclusions Our xenomonitoring approach unveiled 15 trematode species, including nine new records in Zimbabwe. Schistosoma mansoni persists in the study region despite six mass deworming rounds. The high snail and parasite diversity, including the presence of exotic snail species that can impact endemic species and biomedically important trematodes, underscores the need for increased monitoring. Graphical Abstract

In arthropod-associated microbial communities, insect-specific viruses (ISVs) are prevalent yet understudied due to limited infectivity outside their natural hosts. However, ISVs might play a crucial role in regulating mosquito populations and influencing arthropod-borne virus transmission. Some studies have indicated a core virome in mosquitoes consisting of mostly ISVs. Employing single mosquito metagenomics, we comprehensively profiled the virome of native and invasive mosquito species in Belgium. This approach allowed for accurate host species determination, prevalence assessment of viruses and Wolbachia , and the identification of novel viruses. Contrary to our expectations, no abundant core virome was observed in Culex mosquitoes from Belgium. In that regard, we caution against rigidly defining mosquito core viromes and encourage nuanced interpretations of other studies. Nonetheless, our study identified 45 viruses of which 28 were novel, enriching our understanding of the mosquito virome and ISVs. We showed that the mosquito virome in this study is species-specific and less dependent on the location where mosquitoes from the same species reside. In addition, because Wolbachia has previously been observed to influence arbovirus transmission, we report the prevalence of Wolbachia in Belgian mosquitoes and the detection of several Wolbachia mobile genetic elements. The observed prevalence ranged from 83% to 92% in members from the Culex pipiens complex. IMPORTANCE Culex pipiens mosquitoes are important vectors for arboviruses like West Nile virus and Usutu virus. Virome studies on individual Culex pipiens , and on individual mosquitoes in general, have been lacking. To mitigate this, we sequenced the virome of 190 individual Culex and 8 individual Aedes japonicus mosquitoes. We report the lack of a core virome in these mosquitoes from Belgium and caution the interpretation of other studies in this light. The discovery of new viruses in this study will aid our comprehension of insect-specific viruses and the mosquito virome in general in relation to mosquito physiology and mosquito population dynamics.

Knowledge about biodiversity is largely embedded in a daily growing corpus of over 500 million pages of biodiversity literature that is not machine-actionable. It is thus not open to building a biodiversity knowledge graph, or facilitating the use of artificial intelligence tools. This hinders the completion of a much-needed taxonomic name reference system, prevents the discovery of the biotic interactions underpinning the prediction and understanding of global change trends and consequences, viral spillovers, annotation of genes with their respective phenotypes, and their citations in various domains dealing with biological species such as conservation, agriculture, medicine, life sciences and industry, necessary to achieve the objectives of the Green Deal and address the targets identified in the Global Biodiversity Framework. This Policy Brief highlights key actions that can liberate the scientific data published, exploit their use , promote an enhanced way to publish, and ultimately foster excellence and innovation in biodiversity science, monitoring and conservation.

Asian mock vipers of the genus Psammodynastes and African forest snakes of the genus Buhoma are two genera belonging to the snake superfamily Elapoidea. The phylogenetic placements of Psammodynastes and Buhoma within Elapoidea has been extremely unstable which has resulted in their uncertain and debated taxonomy. We used ultraconserved elements and traditional nuclear and mitochondrial markers to infer the phylogenetic relationships of these two genera with other elapoids. Psammodynastes, for which a reference genome has been sequenced, were found, with strong branch support, to be a relatively early diverging split within Elapoidea that is sister to a clade consisting of Elapidae, Micrelapidae and Lamprophiidae. Hence, we allocate Psammodynastes to its own family, Psammodynastidae new family. However, the phylogenetic position of Buhoma could not be resolved with a high degree of confidence. Attempts to identify the possible sources of conflict in the rapid radiation of elapoid snakes suggest that both hybridisation/introgression during the rapid diversification, including possible ghost introgression, as well as incomplete lineage sorting likely have had a confounding role. The usual practice of combining mitochondrial loci with nuclear genomic data appears to mislead phylogeny reconstructions in rapid radiation scenarios, especially in the absence of genome scale data.

Assessing volcanic hazards in locations exposed to multiple central volcanoes requires to consider multiple potential eruption sources and their respective characteristics. While this is common practice in ashfall hazard assessment, this is generally not considered for topography-controlled volcanic flow processes. Yet, in volcanic areas with closely spaced volcanic systems, eruptions fed from several contrasted volcanic systems might threaten one given area. Considering the case of the Nyiragongo and Nyamulagira volcanoes in the Virunga Volcanic Province (D.R.Congo), we present a method to produce a combined lava flow inundation susceptibility map that integrates both volcanoes. The spatial distribution of the probability of vent opening for the next eruption is separately constrained for both volcanoes based on the mapping of historical and pre-historical eruptive vents and fissures. The Q-LavHa lava flow probability model is then calibrated separately for each volcano, considering several historical lava flows of Nyamulagira (2004, 2006, 2010) and Nyiragongo (2002). The maps for the two volcanoes are thereafter integrated based on a weighted sum of both individual lava flow inundation probability maps, assuming historically-based relative eruption frequency of the two volcanoes. The accuracy of this probabilistic susceptibility map for the most active volcanic region in Africa was unfortunately validated by the May 2021 lava flow produced by Nyiragongo. This map was discussed and validated in 2019 with local scientists, as well as representatives of disaster management and urban planning institutions, but was not included in the regional contingency plan ahead of the 2021 eruption crisis. Updating the volcanic crisis and evacuation management plans with this lava flow probability map could contribute to reinforce risk awareness among the population and inform the future development of the city of Goma.

Identification of fruit fly larvae is difficult due to the limited morphological characteristics present. However, this is the stage at which fruit flies are intercepted at ports of entry through horticultural imports. Molecular tools are useful but are time-consuming and expensive compared to morphological identifications. This project aims to use available information from the literature and our own research to build a multi-entry identification key for thirteen tephritid species and species groups that are of economic concern for the European Union. Third-instar larvae were obtained from different regions and hosts. Thirteen species or representatives of species groups were obtained, including Ceratitis, Dacus, Bactrocera and Zeugodacus spp. The cephalopharyngeal skeletons were dissected out, cleared in a 10% NaOH solution, dehydrated and mounted in Euparal on glass slides. Images of at least 20 larvae/species were captured using a compound microscope fitted with a camera. Measurements were taken of the mounted mandibles and the number of tubules and their position in the anterior spiracles in relation to the cephalic skeleton were noted. Differences between morphometric parameters were tested via ANOVA and verified using discriminant function analysis. A matrix was compiled including nine characters for which significant inter-specific differentiation was preliminarily detected. The key was converted into a mobile application by LucID.

Introduction Schistosomiasis and fasciolosis are snail-borne diseases of great medical and veterinary health importance. The World Health Organization recommends complementing drug treatment with snail control and community involvement for disease elimination, but there is a general lack of snail experts and hence snail distribution data. Therefore, we adopted a citizen science approach and involved citizens in the monitoring of medically and veterinary important snail taxa. Materials and methods Snail data was collected weekly by 25 trained citizen scientists (CSs) at 76 sites around southern Lake Albert (Uganda) for 20 months. At each site, snails were searched for 30 minutes, sorted, target snail hosts identified to genus level, counted and data submitted through a smartphone application. The quality of this data was assessed by comparing it to monthly data collected by an ‘expert’ malacologist using the same sampling protocol. Generalised binomial logistic and linear mixed-effects models were used to analyse the variables for agreement between the CSs and expert. Findings The binary agreement in presence/absence of Biomphalaria , Bulinus and Radix snails reported by the expert and CSs ranged between 70% and 86% (900 reports) with an average of 17% false negatives (sites wrongly defined as snail-free). The agreement for Biomphalaria and Radix increased with snail abundance, and false negatives decreased when the number of snails collected by citizens was aggregated per month. Site type significantly predicted binary agreement, which was lowest at lake sites (55%) and highest at spring sites (99%) with variations across genera. Similar temporal trends in snail abundance were recorded despite the expert reporting higher abundance. However, the relative abundance was consistent across site types. The match between the sites with highest Biomphalaria spp. abundance identified by CSs and expert was consistently high (~84.1%) and increased over time. Conclusions and recommendations Our results demonstrate the potential of citizen science to map putative schistosomiasis transmission sites. We therefore argue that this inclusive, powerful and cost-effective approach can be more sustainable than top-down monitoring and intervention campaigns.

Gut microbial communities are critical in determining the evolutive success of fruit fly phytophagous pests (Diptera, Tephritidae), facilitating their adaptation to suboptimal environmental conditions and to plant allelochemical defences. An important source of variation for the microbial diversity of fruit flies is represented by the crop on which larvae are feeding. However, a “crop effect” is not always the main driver of microbial patterns, and it is often observed in combination with other and less obvious processes. In this work, we aim at verifying if environmental stress and, by extension, changing environmental conditions, can promote microbial diversity in Zeugodacus cucurbitae (Coquillett), a cosmopolitan pest of cucurbit crops. With this objective, 16S rRNA metabarcoding was used to test differences in the microbial profiles of wild fly populations in a large experimental setup in Eastern Central Tanzania. The analysis of 2,973 unique ASV, which were assigned to 22 bacterial phyla, 221 families and 590 putative genera, show that microbial α diversity (as estimated by Abundance Coverage Estimator, Faith’s Phylogenetic Diversity, Shannon-Weiner and the Inverse Simpson indexes) as well as β microbial diversity (as estimated by Compositional Data analysis of ASVs and of aggregated genera) significantly change as the species gets closer to its altitudinal limits, in farms where pesticides and agrochemicals are used. Most importantly, the multivariate dispersion of microbial patterns is significantly higher in these stressful environmental conditions thus indicating that Anna Karenina effects contribute to the microbial diversity of Z . cucurbitae . The crop effect was comparably weaker and detected as non-consistent changes across the experimental sites. We speculate that the impressive adaptive potential of polyphagous fruit flies is, at least in part, related to the Anna Karenina principle, which promotes stochastic changes in the microbial diversity of fly populations exposed to suboptimal environmental conditions.

Stress responses are key for parasite survival and, thus, also the evolutionary success of these organisms. However, the evolution of the molecular pathways dealing with environmental stressors are poorly understood as most research focuses either on few selected human-relevant pathogens or major parasite clades. Here, we comparatively investigate, for the first time, antioxidant, heat shock, and behaviour-related genes in the two parasite lineages Cichlidogyrus and Kapentagyrus from the same family Dactylogyridae through whole-genome sequencing data of 11 species. The two lineages differ concerning their species and ecological diversity, which is expected to affect the diversity of their stress responses and, hence, their adaptive potential. Through an exon bait capture approach, we assembled the putative protein sequences of 43 stress-related genes. We discovered that Cichlidogyrus presented higher copy numbers of stress genes (70 kDA heat shock protein, glutathione S-transferase genes) than Kapentagyrus. This difference might explain the ability of species of Cichlidogyrus to colonise various cichlid and non-cichlid lineages. In comparison to most other organisms studied so far, we also observed a previously unreported absence of cytochrome P450 and sigma class glutathione S-transferase in monogenean flatworms. This pattern aligns with previously published genome annotations of monogeneans.

Selfing or mating between related individuals can lead to inbreeding depression (ID), which can influence the survival, growth and evolution of populations of tree species. As selective logging involves a decrease in the density of congeneric partners, it could lead to increasing biparental inbreeding or self-fertilization, exposing the population to higher ID. We assessed the influence of inbreeding on the growth of a commercial timber species, Pericopsis elata (Fabaceae), which produced about 54% of self-fertilized seedlings in a natural population of the Congo basin. We followed the survival and growth of 540 plants raised in a plantation along a gradient of plant density (0.07 to 15.9 plants per m ² ). Parentage analysis allowed us distinguishing selfed and outcrossed seedlings. The annual growth was higher for outcrossed than selfed plants, on average by 10.8% for diameter and 12.9% for height growth. Based on the above ground biomass after 41 months, we estimated ID at δ = 0.32, while a life-time estimate of ID based on the proportions of selfed plants at seedling and adult stages led to δ = 0.7. The level of ID on growth rate did not change significantly with age but tended to vanish under high competition. P. elata is a particularly interesting model because inbreeding depression is partial, with about 26% of reproducing adults resulting from selfing, contrary to most tropical tree species where selfed individuals usually die before reaching adulthood. Hence, the risks of ID must be considered in the management and conservation of the species.

Objectives Integration reflects the level of coordinated variation of the phenotype. The integration of postcranial elements can be studied from a functional perspective, especially with regards to locomotion. This study investigates the link between locomotion, femoral structural properties, and femur‐pelvis complex morphology. Materials and Methods We measured (1) morphological integration between femoral and pelvic morphologies using geometric morphometrics, and (2) covariation between femoral/pelvic morphologies and femoral diaphyseal cross‐sectional properties, which we defined as morpho‐structural integration. Morphological and morpho‐structural integration patterns were measured among humans ( n = 19), chimpanzees and bonobos ( n = 16), and baboons ( n = 14), whose locomotion are distinct. Results Baboons show the highest magnitude of morphological integration and the lowest of morpho‐structural integration. Chimpanzees and bonobos show intermediate magnitude of morphological and morpho‐structural integration. Yet, body size seems to have a considerable influence on both integration patterns, limiting the interpretations. Finally, humans present the lowest morphological integration and the highest morpho‐structural integration between femoral morphology and structural properties but not between pelvic morphology and femur. Discussion Morphological and morpho‐structural integration depict distinct strategies among the samples. A strong morphological integration among baboon's femur‐pelvis module might highlight evidence for long‐term adaptation to quadrupedalism. In humans, it is likely that distinct selective pressures associated with the respective function of the pelvis and the femur tend to decrease morphological integration. Conversely, high mechanical loading on the hindlimbs during bipedal locomotion might result in specific combination of structural and morphological features within the femur.

Background Swimmer's itch, an allergic contact dermatitis caused by avian and mammalian blood flukes, is a parasitic infection affecting people worldwide. In particular, avian blood flukes of the genus Trichobilharzia are infamous for their role in swimmer’s itch cases. These parasites infect waterfowl as a final host, but incidental infections by cercariae in humans are frequently reported. Upon accidental infections of humans, parasite larvae will be recognized by the immune system and destroyed, leading to painful itchy skin lesions. However, one species, Trichobilharzia regenti, can escape this response in experimental animals and reach the spinal cord, causing neuroinflammation. In the last few decades, there has been an increase in case reports across Europe, making it an emerging zoonosis. Methods Following a reported case of swimmer’s itch in Kampenhout in 2022 (Belgium), the transmission site consisting of a private pond and an adjacent creek was investigated through a malacological and parasitological survey. Results Six snail species were collected, including the widespread Ampullaceana balthica, a well-known intermediate host for Trichobilharzia parasites. Shedding experiments followed by DNA barcoding revealed a single snail specimen to be infected with T. regenti, a new species record for Belgium and by extension the Benelux. Moreover, it is the most compelling case to date of the link between this neurotropic parasite and cercarial dermatitis. Additionally, an Echinostomatidae sp. and Notocotylus sp. were isolated from two other specimens of A. balthica. However, the lack of reference DNA sequences for these groups in the online repositories prevented genus- and species-level identification, respectively. Conclusions The presence of T. regenti in Belgium might have severe clinical implications and its finding highlights the need for increased vigilance and diagnostic awareness among medical professionals. The lack of species-level identification of the other two parasite species showcases the barcoding void for trematodes. Overall, these findings demonstrate the need for a Belgian framework to rapidly detect and monitor zoonotic outbreaks of trematode parasites within the One Health context. Graphical Abstract

Citizen science (CS) is gaining global recognition for its potential to democratize and boost scientific research. As such, understanding why people contribute their time, energy, and skills to CS and why they (dis)continue their involvement is crucial. While several CS studies draw from existing theoretical frameworks in the psychology and volunteering fields to understand motivations, adapting these frameworks to CS research is still lagging and applications in the Global South remain limited. Here we investigated the reliability of two commonly applied psychometric tests, the Volunteer Functions Inventory (VFI) and the Theory of Planned Behaviour (TPB), to understand participant motivations and behaviour, in two CS networks in southwest Uganda, one addressing snail-borne diseases and another focused on natural hazards. Data was collected using a semi-structured questionnaire administered to the CS participants and a control group that consisted of candidate citizen scientists, under group and individual interview settings. Cronbach’s alpha, as an a priori measure of reliability, indicated moderate to low reliability for the VFI and TPB factors per CS network per interview setting. With evidence of highly skewed distributions, non-unidimensional data, correlated errors and lack of tau-equivalence, alpha’s underlying assumptions were often violated. More robust measures, McDonald’s omega and Greatest lower bound, generally showed higher reliability but confirmed overall patterns with VFI factors systematically scoring higher, and some TPB factors—perceived behavioural control, intention, self-identity, and moral obligation—scoring lower. Metadata analysis revealed that most problematic items often had weak item–total correlations. We propose that alpha should not be reported blindly without paying heed to the nature of the test, the assumptions, and the items comprising it. Additionally, we recommend caution when adopting existing theoretical frameworks to CS research and propose the development and validation of context-specific psychometric tests tailored to the unique CS landscape, especially for the Global South.

Tropical forest phenology directly affects regional carbon cycles, but the relation between species‐specific and whole‐canopy phenology remains largely uncharacterized. We present a unique analysis of historical tropical tree phenology collected in the central Congo Basin, before large‐scale impacts of human‐induced climate change. Ground‐based long‐term (1937–1956) phenological observations of 140 tropical tree species are recovered, species‐specific phenological patterns analyzed and related to historical meteorological records, and scaled to characterize stand‐level canopy dynamics. High phenological variability within and across species and in climate–phenology relationships is observed. The onset of leaf phenophases in deciduous species was triggered by drought and light availability for a subset of species and showed a species‐specific decoupling in time along a bi‐modal seasonality. The majority of the species remain evergreen, although central African forests experience relatively low rainfall. Annually a maximum of 1.5% of the canopy is in leaf senescence or leaf turnover, with overall phenological variability dominated by a few deciduous species, while substantial variability is attributed to asynchronous events of large and/or abundant trees. Our results underscore the importance of accounting for constituent signals in canopy‐wide scaling and the interpretation of remotely sensed phenology signals.

Background Taxonomic identification of wood specimens provides vital information for a wide variety of academic (e.g. paleoecology, cultural heritage studies) and commercial (e.g. wood trade) purposes. It is generally accomplished through the observation of key anatomical features. Classic methodologies mostly require destructive sub-sampling, which is not always acceptable. X-ray computed micro-tomography (µCT) is a promising non-destructive alternative since it allows a detailed non-invasive visualization of the internal wood structure. There is, however, no standardized approach that determines the required resolution for proper wood identification using X-ray µCT. Here we compared X-ray µCT scans of 17 African wood species at four resolutions (1µm, 3µm, 8µm and 15µm). The species were selected from the Xylarium of the Royal Museum for Central Africa, Belgium, and represent a wide variety of wood-anatomical features. Results For each resolution, we determined which standardized anatomical features can be distinguished or measured, using the anatomical descriptions and microscopic photographs on the Inside Wood Online Database as a reference. We show that small-scale features (e.g. pits and fibres) can be best distinguished at high resolution (especially 1µm voxel size). In contrast, large-scale features (e.g. vessel porosity or arrangement) can be best observed at low resolution due to a larger field of view. Intermediate resolutions are optimal (especially 3 µm voxel size), allowing recognition of most small- and large-scale features. While the potential for wood identification is thus highest at 3µm, the scans at 1µm and 8µm were successful in more than half of the studied cases, and even the 15µm resolution showed a high potential for 40% of the samples. Conclusions The results show the potential of X-ray µCT for non-destructive wood identification. Each of the four studied resolutions proved to contain information on the anatomical features and has the potential to lead to an identification. The dataset of 17 scanned species is made available online and serves as the first step towards a reference database of scanned wood species, facilitating and encouraging more systematic use of X-ray µCT for the identification of wood species.

This paper describes the design and build of a pilot Natural Sciences Collections Digitisation Dashboard (CDD). The CDD will become a key service for the Distributed System of Scientific Collections Research Infrastructure (DiSSCo) and aims to improve the discoverability of natural science collections (NSCs) held in European institutions, both digitised and undigitised. Furthermore, it will serve as a dynamic visual assessment tool for strategic decision-making, including the prioritisation of digitisation. The CDD pilot included high-level information from nine European NSCs, covering the number of objects, taxonomic scope, storage type, chronostratigraphy (Earth Science Collections), geographical region and level of detail in digitisation. This information is structured through a standard Collection Classification Scheme, which uses high-level categorisation to describe physical natural science collections.