From a Long-distance Threat to the Invasion Front: Invasive Aedes Mosquito Species in Belgium Between 2007 and 2020

Abstract

Background: Invasive mosquito species (IMS) and their associated mosquito-borne diseases are emerging in Europe. In Belgium, the first detection of Aedes albopictus occurred in 2000 and of Aedes japonicus in 2002. Early detection and control of these IMS at points of entry (PoE’s) are of paramount importance to slow down any possible establishment. This paper gives an account of the IMS surveillance in Belgium between 2007 and 2020 and reviews the introductions and establishments recorded in that period.Methods: In total 52 PoE’s were monitored at least once for the presence of IMS between 2007 and 2020. These included used tyre and lucky bamboo import companies, airports, ports, parking lots along highways, shelters for imported cutting plants, wholesale markets, industrial areas, recycling areas, and cemeteries and an allotment garden at the country border with colonised areas. In general, monitoring was performed between April and November. Mosquitoes were captured with adult and oviposition traps, as well as by larval sampling. A logistic regression was performed to investigate the percentage of positive PoE’s for Ae. albopictus over the years. Results: Aedes albopictus has been detected at ten PoE’s, Ae. japonicus at three PoE’s and Aedes koreicus at two PoE’s. The latter two species have established overwintering populations. The percentage of PoE’s positive for Ae. albopictus increased significantly over time. Aedes albopictus is currently entering Belgium through lucky bamboo trade, used tyre trade and passive ground transport, while Ae. japonicus only through the latter two pathways. In Belgium, the import through passive ground transport was first recorded in 2018 and its importance seems to grow.Conclusion: Belgium is currently at the invasion front of Ae. albopictus and Ae. japonicus. The surveillance and control management actions at well-known PoE‘s associated to long-distance introductions are more straightforward than at less-defined PoE’s associated with short-distance introductions from colonised areas. These latter PoE’s represent a new challenge for IMS management in Belgium in the coming years and stresses the urgence of implementing a sustainable, structured and long-term IMS management programme, integrating active and passive surveillance and control.

Aedes koreicus, a vector on the rise: Pan-European genetic patterns, mitochondrial and draft genome sequencing

“…Aedes koreicus was first detected out of its native area in Belgium in 2008, in an industrial area in Maasmechelen, province of Limburg, where it is established and overwintering [ 7 ]. While the population is still present, it does not seem to colonize the surrounding territory [ 8 ]. Then, the species was found in northeast Italy in 2011, in the province of Belluno, Veneto region [ 9 ], where it has rapidly expanded its range.…”

MEMO: Monitoring of exotic mosquitoes in Belgium

“…Following previous exotic mosquito species (EMS) surveillance projects in Belgium [ 1 ] , a 3-year national active EMS monitoring project ‘MEMO: Monitoring of Exotic MOsquitoes in Belgium’ started in July 2017. MEMO forms part of the early detection of exotic mosquito species (EMS) along high-risk introduction routes in Belgium, where data are collected at defined points of entry (PoEs) using a standardised protocol.…”