Our own nature reserve, Foxearth Meadows on the border of Essex and Suffolk, is a bit of a hotspot for dragonflies and damselflies. One of the species that can be seen there is willow emerald Chalcolestes viridis, a climate change colonist that first appeared in this country in numbers in 2009. It’s an unusual species, a damselfly that rests with its wings sticking out at an angle (most of our damsels hold them along their ‘back’), and that lays its eggs into twigs overhanging water.
In North America, the emerald damselflies are known as ‘spreadwings’, a name that makes sense given how these insects hold their wings when at rest. On 16 September 2025, Steven Esau, A Rocha Canada’s Water Quality Technician, was checking out the dragons and damsels at a small pond at the Brooksdale Environmental Centre. Among the more numerous spotted spreadwings Lestes congener, was a noticeably bigger beast perched on reedmace, and, unlike the spotted spreadwings, this one had pale wing marks (pterostigmata). Steven photographed the mystery insect and it turned out to be quite a find – a California spreadwing Archilestes californicus, the first record of this species in Metro Vancouver, and the first ever in Canada on the western side of the Cascade mountains. This species’ range stretches from British Colombia in the north through California, New Mexico and Arizona and into Sonora and Baja California in Mexico. Steven’s sighting is evidence of an ongoing northward range expansion, which has been going on for the last 20 years, the reasons for which are unclear. Steven had three sightings of this spreadwing in 25 minutes, and there have been none since.
Like willow emerald, California spreadwing lays its eggs into trees – typically, alder and willow branches. It can however, be a substantially bigger beast than willow emerald. Willow emerald is 39-48mm long; California spreadwing is 42-60mm long and is British Colombia’s largest damselfly species. To quote Steven, ‘In the world of insects, a keen observer has good odds of eventually seeing something that has never been documented before: a new location, behaviour, or interaction’. Steven has now co-authored and submitted a paper about the sighting to British Colombia’s Entomological Society, which you can read here.
