Aedes 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.
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RBINS Staff Publications 2025
Extreme-wave events (tsunamis, storm surge and waves) pose significant hazards to coastal communities worldwide. Onshore deposits from these events significantly enhance our understanding of their long-term frequency-magnitude patterns, which are usually not covered by historical and instrumental documentation. Such perspectives are crucial for successful coastal hazard assessments and consequential efforts to mitigate against the loss of life and assets. Methods enabling reliable and consistent differentiation between the sedimentary evidence for tsunamis and storms remain elusive as deposits from both processes share a number of sedimentary criteria. Microfossil approaches (foraminifera, ostracods, diatoms) have yielded promising progress towards conclusive identification (PILARCZYK et al., 2014), however dissolution and bacterial degradation of carbonate tests often prevent microfossil identification. To address this issue in a pioneering project kicked-off in late 2017, we aim at using high-throughput, metagenomic sequencing techniques to identify marine organisms in onshore sand layers from their DNA remains and to unravel cryptic diversities. We focus on foraminifera, single-celled protists, which show depth-related zonation in subtidal environments and have already been traced successfully in palaeo-tsunami deposits by their ancient DNA (SZCZUCIŃSKI et al., 2016), and compare classic and molecular methods for their identification. Three objectives will be followed to reach this goal: 1. Quantify the relationship between water depth and the distribution of different species of foraminifera using both classic assemblage methods and metagenomic approaches. 2. Assess the potential for identifying key indicator species in extreme-wave deposits in different climate settings based on both assemblage approaches and metagenomic high-throughput sequencing techniques; 3. Establish how metagenomic approaches contribute to consistent and reliable differentiation between the sedimentary evidence for storms and tsunamis in coastal settings. The three key field areas, which share an abundance of published, well-dated evidence for both storms and tsunamis, comprise the Shetland Islands, south central Japan, and southern Chile. The Shetland Islands have a temperate oceanic climate, and near-shore lakes and coastal peat lowlands feature sand sheets deposited by the submarine Storegga landslide around 8 ka years ago and a younger tsunami dated to 1.5 ka (e.g. BONDEVIK et al., 2005). Extreme-wave deposits from south central Japan, underlying a subtropical climate, are available through the ongoing BELSPO BRAIN-be-funded QuakeRecNankai project, focusing on records of past earthquakes and tsunamis along the Nankai Trough (GARRETT et al., 2016). At temperate-humid Chaihuin, southern Chile, deposits of the 1960 Chile tsunami and several older events have been documented (HOCKING & GARRETT, 2016) and sampled for identification of foraminiferal assemblages based on DNA remains. REFERENCES BONDEVIK, S., MANGERUD, J., DAWSON, S., DAWSON, A. & LOHNE, Ø. 2005. Evidence for three North Sea tsunamis at the Shetland Islands between 8000 and 1500 years ago. — Quaternary Science Reviews, 24: 1757–1775. GARRETT, E., FUJIWARA, O., GARRETT, P., HEYVAERT, V.M.A., SHISHIKURA, M., YOKOYAMA, Y., HUBERT-FERRARI, A., BRÜCKNER, H., NAKAMURA, A., DE BATIST, M. & THE QUAKERECNANKAI TEAM. 2016. A systematic review of geological evidence for Holocene earthquakes and tsunamis along the Nankai-Suruga Trough, Japan. — Earth-Science Reviews, 159: 337–357. HOCKING, E. & GARRETT, E. 2016. Geological records of recent and historical ruptures of the Chilean subduction zone: a latitudinal transect of earthquake deformation and tsunami inundation. — Geophysical Research Abstracts, 18: EGU2016-938. PILARCZYK, J.E., DURA, T., HORTON, B.P., ENGELHART, S.E., KEMP, A.C. & SAWAI, Y. 2016. Microfossils from coastal environments as indicators of paleo-earthquakes, tsunamis and storms. — Palaeogeography, Palaeoclimatology, Palaeoecology, 413: 144–157. SZCZUCIŃSKI, W., PAWŁOWSKA, J., LEJZEROWICZ, F., NISHIMURA, Y., KOKOCIŃSKI, M., MAJEWSKI, W., NAKAMURA, Y. & PAWLOWSKI, J. 2016. Ancient sedimentary DNA reveals past tsunami deposits. — Marine Geology, 381: 29–33.
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RBINS Staff Publications 2017