We found this beastie clinging to our wine bottles one morning, any chance you could clarify its species? We guessed at a Modest Sphinx. Do you think it is unusual for this to be found in the UK? I see from your site that it is really only native to US and Canada. I look forward to your response.
This looks very similar to the U.S. Modest Sphinx, but I have located a site dedicated to British Hawkmoths that lists it as a Poplar Sphinx. So, they have the same food plant. They seem to be closely related despite having different genus names. Perhaps some taxonomy needs to be done here. Here is what the site reports: “Poplar Hawk-Moth (Laothoe populi ) The most frequently seen of all the reserve’s hawk-moths and may be on the wing from late May until early August. The peak period though is July, when moth-trapping sessions can produce 5-10 on a single night. The larvae are probably dependant on either white poplar or sallow as a foodplant. “