Cryptic Wood White (Leptidea juvernica) in Ireland

Bánóg choille dhorcha in Gaeilge. The Cryptic Wood White, Leptidea juvernica, was described as a species distinct from the Wood White in 2011 and is the widespread Leptidea across most of Ireland.

Identify it in four steps

1. Small, delicate white with a rounded wing shape and a slow, drifting flight low through grass and rush.
2. Underside hindwing pale grey-green with a faint diagonal band; the upperside forewing tip carries a small dark smudge in males, absent or reduced in females.
3. Cannot be reliably separated from the Wood White (Leptidea sinapis) in the field on wing pattern alone; identification depends on genitalia dissection or well-supported locality context.
4. Wingspan 36 to 48 mm; flight is a low, slow bounce through the sward, characteristic of the genus.

Habitat in Ireland

The Cryptic Wood White uses damp unimproved grassland, road verge, cutover peatland edge, and old railway line. It depends on Meadow Vetchling (Lathyrus pratensis), Bird’s-foot Trefoil (Lotus corniculatus), Bush Vetch (Vicia sepium), and Tufted Vetch (Vicia cracca) as its principal larval foodplants.

Two broods a year in Ireland in most years: a May-June flight and a smaller July-August second brood. Genetic work by Dincă, Lukhtanov, and Talavera (2011) established the species as distinct from the Wood White; earlier Irish records under the name Wood White are now referred here.

Where to see it

• the Burren, County Clare: limestone grassland and green roads support the species from May onward.
• Lough Boora Discovery Park, County Offaly: cutover peatland margins with vetches hold reliable populations.
• Wicklow lowland verges and old railway routes: sheltered grassy corridors with Meadow Vetchling.

Related species

• Wood White (Leptidea sinapis)
• Small White (Pieris rapae)
• Orange Tip (Anthocharis cardamines)