Thanks for being gentle! I took the day off last Friday and spent an amazing day in Ashdown Forest with PLs rushing past every minute or so. It was incredible to see that 95% of them followed precisely parallel flight paths - approximately due North. Almost like drawing a series of grid lines across...

A scientific question for you to contemplate... As there doesn't appear to be any noticeable Southerly migration back towards their original homeland in late summer, what is the evolutionary benefit which encourages these insects to fly so far? I have been thinking about this! I am not a scientist ...