Geometridae, Ennominae Wingspan 32-40mm.

One of the most powerful "Thorn" species in the UK, it is a very fast flyer and not too easy to capture, even when attracted to light. A common species throughout the UK and it is found in mixed woodland mainly in central and eastern Cornwall. A very distinctive species with the bright yellow thorax, and, at rest, the wings are sharply swept back as shown above.

The flight season in the UK is late July to mid October, with a peak occurring in August / September.