The sun is shining, the skies are blue and we're thoroughly enjoying the tail-end of summer here at RSPB Sandwell as we head into mid-September towards the autumn equinox and the changing of the seasons. Out on the lake we're busy starting work on the islands - thanks to support from the Environment Agency Perry Barr and Witton flood risk management scheme - and many of our work party volunteers are getting stuck in and helping out. But last week the party had an additional member when they returned home from one of the islands...

Sitting quietly on a crack willow branch was a caterpillar. It was bright green with a little curved horn at the tail end, oblivious to the machinery and people working hard to re-landscape the island around it. With so much work going on the team decided it would be safer to bring the caterpillar back with them. Initially the caterpillar was identified as a lime hawkmoth, but after another look it was found to be an eyed hawkmoth. The difference is only very slight and can be quite difficult to spot.

A lime hawkmoth feeds mainly on lime trees (hence its name). It has bright yellow stripes with a slight red stripe alongside and a short blueish spike at the tail.

The eyed hawkmoth however is particularly fond of willow trees. It has yellowy-white stripes with a blue horn at the tail end. If you look closely at the last stripe you can see the white merges into the blue of the tail, and if you look at its head you can see the shape is quite triangular and has a vivid yellow stripe along the edge. The eyed hawkmoth is also slightly bigger than the lime, growing up to 6-7cm larger in length.

The eyed hawkmoth caterpillar is now safely housed with one of our volunteers, happily eating its way through many willow leaves and branches.

Photographs by Andy Purcell

RSPB Sandwell, September 2019