July Highflyer Geometridae

Hydriomena furcata (Thunberg, 1784)

Description: Wingspan 26-39mm. An extremely variable species with many colour forms ranging from green through to brown. Individuals found on upland sites, or where Bilberry Vaccinium myrtillus is the main foodplant, tend to be smaller and darker than those found in lowland habitats. Most colour forms have darkish bands which vary in intensity and pattern. Most specimens have an apical streak on the forewings.

Similar Species: Adults bear a close resemblance and share similar habitats to both the May and Ruddy Highfliers. The former lacks the apical streak and has a small discal spot on the underside of the forewing. The latter has paler hindwings. Both these species also have earlier flight periods.

Key Identification Features:

Sets:  male upperside

Flight Period: From early June to mid-September.

Status: Common and widespread throughout all counties including Rathlin Island, Antrim.

Ecology: It occurs on a wide variety of habitats such as woodland margins, clearings, bogs, fens, moorland and suburban gardens. Adults are attracted to light often in large numbers. They are occasionally disturbed from the trunks of trees, branches and foliage during the day. The larvae can be found in May and early June on Bilberry Vaccinium myrtillus, Heather Calluna vulgaris, Hazel Corylus avellana and willow Salix spp. It overwinters as an egg stage.

World Distribution: Throughout Europe including Iceland as far east as China and Japan.

Bradley & Fletcher number: 1777 Agassiz number: 70.074

Additional information:

UK Moths account


 Thompson, R. S. & Nelson, B., 2003 (Oct 2). [In] The Butterflies and Moths of Northern Ireland