Hydriomena impluviata
In 3 days ~20% in a week ~40%
The May highflyer (Hydriomena impluviata) is a moth of the family Geometridae. It is found across the Palearctic region and the Near East although its range is largely determined by the presence of its larval food plant. The species was first described by Michael Denis and Ignaz Schiffermüller in 1775.
The wingspan is 30–34 mm and it is quite variable in markings, the best identification feature being four square spots along the costa of each forewing, although these may not be visible in the frequent melanic forms. "Individual specimens of coerulata (synonym of impluviata) bear a very close resemblance to Hydriomena ruberata. coerulata (impluviata) is perhaps on an average slightly smaller, is somewhat shorter-winged, oftener with a very pale, blue-green median band, the oblique subbasal line is straight, or only very weakly angulated in the cell, the black marks on the hindmargin of the forewing and on the anterior veins distally, which generally characterize both species, on an average less strongly developed than in ruberata but very variable in both species".
The larva is relatively powerful and dark red-purple in colour. It has some short setae. The species flies at night from May to July [1] and is attracted to light. The larva feeds on the leaves of alder, spinning two leaves together so it can feed undisturbed. The species overwinters as a pupa under loose alder bark.
^The flight season refers to the British Isles. This may vary in other parts of the range. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Wadden Sea National Park | 🇩🇪 Germany |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Liverpool | 🇬🇧 United Kingdom | |
| 2 | Birmingham | 🇬🇧 United Kingdom |
With luck
About 10% of wildlife watchers report a May Highflyer sighting in Liverpool on a given day, based on 12 verified sightings from GBIF citizen-science data. It is the 389th most-seen of the 632 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
In that month about 20% of wildlife watchers report a May Highflyer in Liverpool on a given day, against under 5% in June to March, the lowest months.
Between 6 and 9 am
Across all the parks we cover, that three-hour window holds the most May Highflyer sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is most active around dawn and dusk.
Yes
Of the 2 cities where we can rate May Highflyer sightings, Liverpool has the highest daily chance: about 10%. Next come Birmingham (United Kingdom, under 5%).
Same family: Geometridae
The closest relatives of the May Highflyer that you can see in Liverpool (family Geometridae, Geometer Moths) are Willow Beauty (about 40%), Marbled Carpet Moth (about 30%) and Brimstone Moth (about 30%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the May Highflyer is recorded against all the insects logged in Liverpool (12 verified sightings), 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.
