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Increasing detections of the invasive mosquito <i>Aedes albopictus</i> in Belgium
No full textAedes albopictus is an invasive mosquito species expanding its territory in Europe, posing a health risk as the species is a competent vector of dengue, chikungunya and Zika virus. In European countries autochthonous transmission of these viruses are reported in localities where the species is established. In Belgium the introduction of Ae. albopictus was first monitored through active surveillance at Points of Entry (PoEs). Since 2018, the increased observation of Ae. albopictus at parking lots located along the highways suggested a rise in introduction through route traffic. Hence, in 2022, a passive surveillance based on citizen science was implemented to complement the active surveillance and expand the coverage of the monitoring countrywide. We present the current situation for Ae. albopictus in Belgium based on the results of both active and passive surveillance. Via an online platform (web/app), citizens uploaded pictures of potential Ae. albopictus specimens after answering filtering questions about morphological characteristics of the mosquito related to its size, color and stripes on the hind legs. Subsequently, pictures were then analysed to determine whether or not it is Ae. albopictus. When Ae.albopictus was confirmed on the picture, a field inspection was performed. This inspection included larval sampling and the set-up of ten oviposition traps for one or two weeks around the notification point. Additionally, in 2022 and 2023, ten oviposition traps were set-up at eight parking lots between May and October. In 2023, a longitudinal surveillance was also implemented to monitor overwintering and potential spread at two locations where the presence of Ae. albopictus was confirmed in 2022. In 2024, overwintering monitoring happened through larval sampling at four locations where Ae. albopictus was detected in 2023. DNA-based validation of all life stages of Ae. albopictus collected during field visits from several locations was performed to validate the identification of the species, and to investigate the haplotype composition of the population. We received 12 notifications of Ae. albopictus from citizens from nine locations in 2022, 29 from 15 new locations in 2023 and 47 from 12 new locations in 2024. Overall, Ae. albopictus was detected at 36 locations in Belgium over these three years. Further, the exotic species was detected in 2022 at three, and in 2023 at seven parking lots. Longitudinal surveillance in 2023 confirmed the presence of Ae. albopictus at two locations, indicating local establishment and overwintering. In 2024, overwintering was confirmed at another three locations. Prior to 2022, Aedes albopictus was in the early stage of its invasion process in Belgium, with confirmed occurrences limited to PoEs. Since 2022, the implementation of citizen surveillance has led to a steep increase in detections, including in residential areas, alongside numerus findings at parking lots. Additionally, the confirmation of overwintering at five locations, indicates that the species is being increasingly imported into Belgium via ground vehicular traffic and has become locally established in recent years
ENFORCE: Expertiserapport ref: exp-569 (plaat 1, staal A - 00023200) & exp-570 (plaat 2, staal A - 00023202) - 27/8/2024
No full textAlonso Berruguete et le Nord : liens avec sculpteurs flamands et bourguignons dans la péninsule ibérique
No full textDe l'Europe du Nord à la péninsule ibérique : une histoire artistique transnationale de la sculpture entre les Pays-Bas méridionaux et le Portugal de la première modernité, journée d'études à l'Université catholique de Louvain (UCL), 31.01.2025
Fluid flow in the Katanga Supergroup: From Lufilian brittle tectonic stages to the post-Lufilian period (Democratic Republic of Congo)
No full textThe metasedimentary rock succession of the Neoproterozoic-Cambrian Katanga Supergroup in the Central Africa Copperbelt shows evidence of several complex tectonic events. The deformation of this supergroup started from the tectonic inversion at about 570 Ma and lasted up to today, but reached paroxysm at ~550 Ma. This long period was characterized by folding and faulting throughout multiple compressive and extensional events, which controlled the regional fluid flow on the one hand, and played an important role during formation of the stratiform to stratabound Cu-Co (Ni, U) deposits and the polymetallic Cu-Zn-Pb (Ag, Ge, Mo, Cd) vein type deposits on the other hand. Based on the structural analysis and paleostress reconstruction, coupled with fluid inclusion characterization from mineralized structures in rocks from the Nguba, Kundelungu and Biano Groups, this study demonstrates that the composition of hydrothermal fluids changed during brittle tectonic deformation during the Lufilian orogeny and subsequent uplift and post-Lufilian faulting. During early brittle tectonic deformation along strike slip faults with sinistral and dextral movement related to a NE-SW transpression, the Cu-mineralizing fluid was hypersaline (27.9 31.1 eq. wt% NaCl) with moderate temperatures (Th = 128 216 ◦C). The subsequent Cu or Cu (Zn, Pb) mineralization formed within an E-W extensional stress regime, related to the late Lufilian orogenic collapse. The fluid inclusions present in the gangue minerals associated with this latter mineralization show a large range in Th (50 264 ◦C) and salinity (26.7 36.0 eq. wt% NaCl). The decrease in temperature is interpreted to be due to migration of the fluids at shallower depth in the subsurface after uplift and erosion of the orogen. The increased salinity of the fluid is related to the dissolution of evaporites, mainly NaCl. A second H2O-NaCl-CaCl2 fluid with a homogenization temperature below 55 ◦C has also been found associated with this brittle stage and mineralization phase, but only in rocks belonging to the Kundelungu Group. A third mineralization phase, also characterized by Cu or Cu (Zn, Pb), formed during the post-Lufilian period within a NW-SE transpressional inversion regime. The fluid inclusion in the gangue minerals of this mineralization phase have a smaller range in homogenization temperature (Th = 37 172 ◦C) and the largest range in salinity (0.71 30 eq. wt% NaCl), compared to the earlier fluid inclusions generations. This large range in salinity may be explained by the mixing of a high salinity fluid, already present during the earlier tectonic stages in the sedimentary basin, with meteoric water. During the more recent riftrelated extension, a fluid with again a large and higher range in homogenization temperatures (Th = 47 257 ◦C) and with a typical low salinity (<10 eq. wt% NaCl) has been recognized in minerals filling NNE-SSW to NE-SW oriented faults and fractures. The upward migration of a relatively low-salinity fluid from deeper parts in the subsurface explains the variation in the temperatures observed with this tectonic event
Interconnected multi-layer aquifer with evaporitic fossil waters in Chott-El-Gharbi endorheic basin (Western high plateaus, Algeria): Hydrochemistry, environmental and strontium isotopes.
No full textWetland are of paramount importance for the entire province of Nâama as well as for the entire Algerian Western High Plateaus. One of them, Chott El Gharbi, is a major but poorly-known hydrogeological unit shared between Algeria (80%) and Morocco (20%). Chott El-Gharbi is a multi-layered aquifer system whose most productive layers are the Middle Jurassic (Bajocian-Bathonian dolomite and limestone) and the Cenozoic continental sediments (lacustrine intercalation of clays and limestones, marls and sands). Groundwaters exhibit depleted δ18O (− 8.98 to − 5.53 ) and δ2H (− 69.4 to − 48.0 ) isotope ratios linked to an evaporative process. Groundwaters are old, with 14C activities from 2 pmC to 58 pmC and residence times of 23 ky to 9 ky. These old recharges occurred during a more humid and colder epoch. 87Sr/86Sr ratios, coupled with major element abundances, determine that Gharbi waters resulted from the mixing of waters having been in contact with the Triassic evaporite-rich sequence (0.70810, rich in sulfates) and waters in contact with Lago Mare (late Miocene) sequence (0.70875, less rich in sulfates). Water with Triassic signature is present in the Jurassic aquifer (Bathonian-Bajocian) while water with Lago Mare or mixed signature is present in the Miocene, locally along faults in the Jurassic aquifer. 14C ages indicate that the mixing process occurred at c. 10,000 years along faults probably during an active tectonic period. Waters with modern signature are only known outside the endorheic Gharbi basin in shallow Jurassic aquifers. The Gharbi aquifer system is separated from the large Chergui aquifer system to the east
Biodiversity of the freshwater crabs of Benin: a genetic approach
No full textIntroduction: Published reports on freshwater crabs in Benin (West Africa) are very scarce and mention only two accepted taxa: Sudanonautes aubryi and S. monodi (the latter with no precise locality). The inventory of these species (described using specimens from Gabon and Cameroon, respectively) is still poorly known. Methods: Here, we explore the diversity of freshwater crabs in Benin using a selection of 18 specimens collected in 2022 and 2023 in a range of aquatic biotopes and throughout the country, except for the far north. The specimens were examined morphologically and sequenced for fragments of the COI, 16S and H3 genes. Results: Despite a general variability in color, shape, size and in the DNA sequences (proportion of substitution per site up to ca. 8% for COI, 3% for 16S and 0.3% for H3), our results suggest that all the Beninese crabs belong to a single species of the Sudanonautes genus. They also show that they are neither S. aubryi nor S. floweri, with which they show consistent morphological differences and larger proportions of substitution per site at COI (>10%), 16S (>6%) and H3 (>0.6%). Conclusions: The Beninese crabs may belong to an undescribed species. However, they are more likely conspecific with S. pelii, a species described from the coastal plain of Ghana, previously considered to be a junior synonym of S. aubryi, and whose lectotype s photographs show no obvious morphological differences with the Sudanonautes crabs from Benin. It is therefore likely that S. pelii will have to be revalidated for certain populations of Sudanonautes crabs from Ghana, Benin and probably adjacent countries
