Description: Wingspan 29-34mm. The green coloration is prone to fading after emergence. Newly emerged adults are darkish green with two median cross lines and have chequered fringes around the periphery of both wings. The median lines become less apparent as the colour fades. The hindwing is sharply angled. Beginning of July to mid-August.

Irish Distribution: This is a scarce and rarely seen species in N. Ireland although its common name would suggest otherwise. The majority of records are from the Peatlands, the Argory and a few other localities in north Armagh. It has a more scattered distribution elsewhere; in Down it has been taken at Derryleckagh and Seaforde Estate. It has also been recorded regularly from Crom Estate and more recently from several other sites in Fermanagh. There is also a single record from the Aghalee area of Antrim. There are no recent records north of Lough Neagh.

Ecology: A scarce species found mainly in open woodland and bogs. The larvae can be found from August to May of the following year on Hawthorn Crataegus monogyna, Blackthorn Prunus spinosa, birch Betula spp., oak Quercus spp. and willow Salix spp. It overwinters as a larva.

Key Identification Features:

• Two wavy white lines on forewings and one across hindwing
• Wing margins with black and white chequered pattern
• Hind wing sharply angled
• Chequered fringes at the periphery of both wings

Distribution Map from NBN: Hemithea aestivaria at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Hemithea aestivaria at iNaturalist World Species Observations database.