Hi all,
For the longest time I've been working on why WNS showed up in 2005-06 when people have been moving between Europe and the USA since the eleventh century. The working hypothesis I've come up with (which you may have heard before) goes like this:
WNS was transported through overnight shipping which proliferated in the 1990s. Bats, trapped in containers and transported via air could only escape once they reached regional destinations such as Albany, NY. Transport via fast shipping is possible (as little as 7 days), but less likely.
This is all very good, but a small doubt remained... why did it take fifteen years for WNS to catch on?
It turns out the period may be much less. In the years immediately following 9/11 virtually all pest inspection was halted at the border. Basically, if it wasn't a bomb, it wasn't acted on or reported. As a result, it took only four years for WNS to take hold - a time line more consistent with the spread of invasive species.
http://m.yahoo.com/w/news_america/ap-im ... lang=en-us