Autumn Larvae

For the last 11 years I've conducted standardised searches for iris larvae in Savernake Forest, Wiltshire. This year's total is 15, the lowest tally during the 11 years.  

There are several reasons, but the three week wet spell in June, when larvae were pupating, is probably the most important - the longer iris spends pupating and as pupae, the fewer adults fly.  

Now, larvae are starting to colour up prior to hibernation (one at Knepp Wildland is about 80% coloured already). 

They construct silk highways up their seat leaf midrib. This one's done that, and has also constructed a bypass! (Savernake, today) -

Sallow Leaf Mildew is prevalent this autumn. It looks as though iris larvae can consume a fair amount of it without ill effect, like this one (feeding damage, top left) -