Going green

Goodness what a night for moths! Well over 300 and still counting here in Thrupp, Oxon, with new species for the year including Drinker, Spindle Ermine, Scarlet Tiger and this delightful Green Silver Lines, plus 12 Elephant Hawks, one tucked up in a row on an eggbox with an Eyed and a Privet like a trio of puddings in a posh restaurant.

The colour green also features in the Thrupp School for Emperors where a couple of the catties have now shed their previously sombre black skins. This prompts me to ask two questions which have long interested me but remain unresolved: first, why are relatively few UK moths green when this is such an important element of camouflage (as I guess their larvae show)? And secondly, more intriguing to me, why do hardly any of them have any blue?  (I guess this also raises questions about the handful which do).

I have Googled at intervals for info on this without success, though exchanges with other amateurs suggested that flying by night might be relevant. Anyway, I'd be very grateful for any thoughts or links to studies of the subject.  Hope your moths have been abundant too.  Martin Wainwright.