Findings and control of two invasive exotic mosquito species in the Netherlands, 2011

[Gert van der Hoek]

Findings and control of two invasive exotic mosquito species, Aedes albopictus and Ae. atropalpus (Diptera: Culicidae) in the Netherlands, 2011

Abstract
In July 2011, during routine invasive exotic mosquito surveillance inspections at companies that
import used tyres, two invasive exotic mosquito species were found at three locations in the
Netherlands: the Asian tiger mosquito (Ae. albopictus) [Stegomyia albopicta sensu Reinert et al.,
2004] and the American rock-pool mosquito (Ae. atropalpus) [Georgecraigius atropalpus sensu
Reinert et al., 2006]. Mosquito control was initiated one week after the first invasive mosquito
was found, using adulticides and larvicides, and continued until the second week of November.
Despite control, findings of these species continued in August and September, with the last
finding in the first week of October. The same species were also found at these sites in 2010,
followed by control until the end of the season. The available surveillance data suggest, although
not conclusive, that the findings of 2011 are the result of unrestricted import of used tyres from
Ae.albopictus- and Ae. atropalpus-endemic areas in 2011, rather than from surviving specimens
found in 2010.

The extensive surveillance in the
surrounding 500m zones around tyre platforms where invasive exotic mosquitoes have been
found strongly suggest that, at least until now, none of the invasive exotic mosquito species
managed to establish in the Netherlands, most likely thanks to active mosquito control in an early
stage of population development both on the tyre platforms, as in the surrounding areas. This
strongly supports the active surveillance, allowing for early detection and subsequent control. It
remains uncertain how long this strategy will remain effective in preventing establishment of
invasive exotic mosquitoes. Unless and until regulations and/or guidelines are developed, put in
place, and complied to, effective biocides are regulated/registered and available for use, invasive
exotic mosquitoes are likely to be found again in the Netherlands, with the risk that at some point
intervention may be too late to prevent establishment.

European Mosquito Bulletin 30 (2012), 1-14
Journal of the European Mosquito Control Association
ISSN 1460-6127; www.e-m-b.org
First published online 17th February 2012