Venusia cambrica
In 3 days ~20% in a week ~40%
Venusia cambrica, the Welsh wave, is a moth of the family Geometridae. It is found in Europe, western and central Siberia, Altai, Transbaikalia, the Russian Far East, the Korean Peninsula, Japan and in North America, where it can be found across Canada from Newfoundland and Labrador to British Columbia, south in the west to California, south in the east to Georgia.
The wingspan is 27–30 mm. The light grey front wing has black and brown cross lines. Two protruding black lines at the outer black cross line, near the middle of the wing, are the most striking characteristic. "Quite distinct. The black marks on the 3rd radial and 1st median distally to the outer line recall Oporinia. English specimens and (according to Herz) the Korean form are on an average rather less white, than those from Scotland and continental Europe. In general the female is slightly larger and paler than the male - ab. pygmaea Tystr. is small with the central area constricted. - ab. latefasciata Strand has the median area very broad, the lines which bound it are parallel, not approximated in the posterior part. - ab. webbi Prout has the markings almcst obliterated excepting at the costal margin and on the median vein and its branches, recalling Oporinia antumnata gueneata See Oporinia gueneata -ab. bradyi Prout has both wings uniformly suffused with dark smoke-colour, and is becoming frequent in the Sheffield district. -ab. lofthousei Prout is a quite different melanotic form from ab. bradyi; forewing suffused with smoke-colour but remaining longitudinally rayed with white in the distal area, hindwing not infuscated. Only known from North Yorkshire. The larva is long and slender, with a few short setae. It is green with large, purple spots on the back and sides.
Adults are on wing from July to August in western Europe, from June to September in New Brunswick and Quebec and from March to August in California. There are two generations per year. The larvae feed on the leaves of Sorbus aucuparia. Other recorded food plants include alder, apple, birch, mountain ash, serviceberry and willow. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Pacific Rim National Park Reserve | 🇨🇦 Canada | |
| 2 | Great Bear Rainforest | 🇨🇦 Canada | |
| 3 | Cairngorms National Park | 🇬🇧 United Kingdom | |
| 4 | Great Smoky Mountains National Park | 🇺🇸 United States | |
| 5 | Olympic National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Seattle | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Welsh Wave Moth sighting in Great Bear Rainforest on a given day, based on 28 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 67th most-seen of the 235 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
May to September
In those months about 10% of wildlife watchers report a Welsh Wave Moth in Great Bear Rainforest on a given day, against under 5% in October to April, the lowest months.
Between 5 and 8 am
Across all the parks we cover, that three-hour window holds the most Welsh Wave Moth sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 5 parks where we can rate Welsh Wave Moth sightings, Great Bear Rainforest ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Pacific Rim National Park Reserve (Canada, about 10%).
GBIF citizen-science records
It is estimated from how often the Welsh Wave Moth is recorded against all the insects logged in Great Bear Rainforest (28 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
