Proserpinus flavofasciata

The only caterpillar I have found was on Fireweed Epilobium angustifolium in August and it fed at a faster rate than I have ever seen in any other caterpillar. Unfortunately it was covered with tachinid eggs and did not survive. Unlike most other sphingids, the caterpillar does not have a horn - only a little coloured button where the horn should be. All the legs and the mandibles of the caterpillar I found were white.