Species account

Enghvidvinge (Leptidea juvernica)    Williams (1946)
   Hvidvinger (Pieridae) [Sommerfugle]    CWWH    25128
Cryptic Wood White (gb)   Ängsvitvinge (se)  
Subspecies
juvernica
Europe.
tchuvilini
Bolshakov (2004) - Armenia.
mazeli
Bolshakov (2006) - Tian Shan.
jonvillei
Mazel (2000) - .
yakovlevi
Mazel (2001) - Novosiberia.
melanogina
Lorkovic (1993) - E Europe to Caucasus.
Measurements:
WS: 39-41mm
Generations:
2
Flight period:
JFMAMJJASOND 
Scan
Identification:
Very similar to sinapis (Skovhvidvinge). Guaranteed identification can only be ascertained by comparing the genitalia which are unique to both.

In the field the males are stronger colored than females, and so is 1. generation compared to 2. generation.

The black spot at the tip of the forewing is the best way to distinguish the two males. Sinapis shows a perpendicular shape, 90 degrees, to the inner corner of the spot. On juvernica the angle is more than 90 degrees causing the black spot to spread out more.

Lars Andersen, danske-natur.dk, mentions that the most reliable field character to distinguish the two males is that sinapis has a more round front edge to the forewing (guess it requires good experience to use this for id).

The females are practically alike but sinapis is in general more white without dark markings other than along the ribbons on the forewing. Here the female still shows the black spot on the forewing similar to the male, but much weaker.

According to Nordens Fjärilar it is also possible to separate the two species by the way they act before mating. When a male and a female are in position the male of sinapis starts waving his proboscis in front of the female and if he after more than 30 seconds start flapping the wings too, then it is with certainty a sinapis, because the male juvernica always keeps the wings together during courtship. However, only if the female accepts the invitation and connects with the male is it possible to id the female, since the two species fly in the same habitats and are known to courtship each other.
Similar species:
Life stages:
Distribution:
Central Europe, Sweden, Finland and Baltics; also Ireland and patchily throughout the rest of Europe and scarcely central Asia.
Habitat:
More specialized than Wood White requiring moist fertile meadows in open land, and is not found in the meager soil forest habitats where sinapis is found.
Behavior:
Flying earlier than Wood White.
Same weak flying pattern.
Host plants:
Preferring
Gul Fladbælg (Lathyrus pratensis) [Meadow Vetchling ~ Gulvial]
but also
Muse-Vikke (Vicia cracca) [Tufted Vetch ~ Arveja Silvestre ~ Kråkvicker]
Almindelig Kællingetand (Lotus corniculatus) [Bird's-foot Trefoil ~ Loto Corniculado ~ Käringtand]
Endemic:
Status
Extinct in Denmark 2004, Bornholm. Scarce in C Sweden and S Finland.
Comment:
QWWH
Quite recently, 2011, this taxon was discovered by Spanish researchers to be different from Réal's Wood White (Leptidea reali), now Sydlig Enghvidvinge, but which arguments are used I'm not sure of, because what often is the most reliable distinction mark on species level, the genitalia, according to information on the English wikipedia site is not useful because they have been found to be similar on both species. But apparently the population in Ireland that belong to present species looks different with stronger base colors.
Cryptic Wood White 1535    (2 photos BOTH SIDES)
2023-06-06    Getå (Norrköping), Sweden

Imago
Meadow east of Getå.
Open meadow making it good for the species, and deciding that the wing spot angle is above 90 degrees, this individual, if any, should be a good candidate for the species.




Cryptic Wood White 1556    (11 photos BOTH SIDES)
2023-06-07    Valdemarsvik (Östergötland), Sweden

Imago
Two animals.
I know you'll ask: How did you separate them from Wood White..?!
Iiiihh...well, I'm not sure if I can. Unfortunately the pattern of the wing tips is not as conclusive as I had hoped for, before getting to see the two species in real life.

Two animals were reported on this meadow a few days before, and I kind of sense that the spot-angle could be wider than 90 degrees and they looked smaller than the other wood whites we had just seen along a forest road...I'll probably degrade them to the uncertain sp-level in a short while, but for the moment I would like to feel the joy of having registered both species. Lifers both!