I'm aware that insects swarm GNC - you should come to the Top End just prior to The Wet and check out the dragonflies, also, large flying ants anywhere in Australia...but a cloud of any insect 80 miles by 80 miles, and the density needed to appear on radar...I'd rather believe that there was an anomaly picked up on radar that was due to atmospheric conditions, or that the weather radar situation was a little bit hows your father...
It wasn't long ago that we could read in the papers about the extinction of garden insects due to certain farming practices in Europe, and now we have an area of 4,096,000 acres, consisting of ladybirds flying above 5,000 feet, with a density of these miniscule insects sufficient to be picked up by radar.
I would've thought that the shape of a ladybirds carapace would've reduced a radar signature too...and how did they know what insect it was at that height, unless they mobilised and went up there.
My theory is that something appeared back at the station on the radar display, and rather than say that the radar wasn't working to its best capacity, instead, they said that there was a swarm of ladybirds 80x80 miles, or flying ants that extended from London, down past Plymouth.
More believable. Innit.