Even our much-revered IRP Heslop never came up with a title like that...
In late October 2013 two iris larvae were found on sallow saplings on the Knepp Castle estate in West Sussex. Their locations were marked. On Sat April 26th I returned and looked for them. One was quickly found, changing skin to enter the 4th instar, having moved about 1.5m from where it was found in October.
Signs of the second larva, a hundred metres away, were readily found - evidence of recent feeding, a silk seat pad on a leaf tip and even the old silk hibernation pad on the stem. But there was no sign of the larva, and the 3m tall bush was searched twice.
My conclusion was that it had been devoured by one of the long-horn cattle that were freely browsing sallow bushes in the vicinity (the site is a pasture-woodland restoration, or re-wilding scheme, with abundant sallow saplings). The cattle were short of grass due to winter poaching damage and a high rabbit population.
It was blowing a gale at the time so photography was difficult, but here's some visual evidence -
Note cattle browsing damage at base of my thumb. Larval damage is more evident in the next picture (right of centre) -
I want to see some punishment...