Today I found six larvae in three hours' searching, which is really quite good - and contrasts with Brother Denis's experiences. Maybe I just hit a purple patch.
I am confident that this year's egg lay was good, despite the fact that adult numbers were ~50% down. This is because the leaves were in the right growth phase for egg laying, for once, due to the latish spring. That's why the females were so (relatively) prominent this season, and so scarce in 2015.
All today's larvae were in late 2nd instar. One was skin changing, note the black horns and yellow collar -
Here's a great bit of larval feeding damage, diagnostic -
At certain angles, the egg case base (larvae eat the top and sides) stands out prominently, and can be more obvious than the larva - see top centre -
This one's recently moved to a new leaf. That's not his feeding damage -
And here's another classic bit of feeding damage -
Conclusion: the 2017 Purple Emperor season is coming along nicely...