Large (cf. my fingers behind) greenish caterpillar feeding on a hybrid poplar.
No interactions present.
How unusual is this red-spotted form? Don't recall seeing it before myself, but there is a similar one shown on http://www.ukleps.org/
Entomologist and biological recorder
I'm afraid I don't know the answer to your question - I had to use the ukleps picture to identify the caterpillar as the pictures in Porter completly threw me!
I have seen a few red-spotted poplar hawk moth caterpillars.
Did you notice the yellow spots on the underside of the leaf. This is a Melampsora sp rust fungus and I would need a microscope to determine which of the two species, allii-populina or larici-populina, it is. It usually is the latter.
Thanks for the additional information; I had noticed last autumn that a number of poplars locally looked a mess with orange/yellow marks, but with the caterpillar tree, it was total focus on the insect in the hope that I wouldn't dislodge it.
I think it's a reasonably uncommon form - I've bred through a thousand or so in the last few years and had a total of maybe 5-6 red-spotted, that I can remember
Record your ladybird sightings!
Lat/Lng: 51.9, -2.1
OS grid ref: SO9925