Purple Emperor larvae remain seriously scarce this autumn: on Saturday, three of us found two larvae in some 15 hours of foliage searching in Savernake. One larva had only just changed into the 3rd instar - its old head was lying close by; that's late.
Tony Kasiske reports a similar scarcity in Germany, again due mainly to poor flight season weather.
Interesting to find a sizeable and healthy-looking larva on a branch heavily infected by Melampsora Willow Rust, note the feeding marks -
Most of Savernake's sallows are in poor condition for larvae, with Willow Rust, Sallow Mildew and Tar Spot. Worse, everywhere, sallows came into leaf unusually early, following the mild winter; this means that the leaves were unsuitably thick and coarse by the time first instar larvae were feeding. It may be that a lot of L1 larvae failed, but we wont know as most egg case bases got washed out by heavy rains.
One again, iris has got to outmanoeuvre a lot of problems if it is to fly in numbers next summer; but don't underestimate him - for a start, it's likely that tit predation of hibernating larvae will be relatively low this coming winter.
Here's what one of my favourite sallows in Savernake looked like on Saturday, with white mildew on a lower bough, sparse and thick-leaved foliage and a lot of Willow Rust (plus squirrel damage, back right). We didn't find anything on it -
And here's what a healthy, suitable sallow should look like in Sept -
complete with damsel not in distress...
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