One was found at Covent Garden flower market, London on 26 April 1984 as a pupa amongst Asparagus plumosa (Asaparagus Fern) imported from Florida, with the adult emerging on 2 May 1984. Resident of North America, found from Texas to Alberta and east to the Atlantic coast, where it can be a commercial pest. A large pale white-tan geometrid with pointed projections along the wing margins; the wings lack conspicuous markings. Univoltine, on the wing from late May to August. Wingspan 36-44 mm. The origin of the British specimen (with imported Asparagus) is somewhat at odds with the larva feeding on a variety of hardwood trees in its native range.
Source: http://entomology.museums.ualberta.ca/searching_species_details.php?s=4194

Updated: July 2020, description and status

Flightime guide
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