Northern Eggar Lasiocampidae

Lasiocampa quercus Palmer, 1847

Description: Wingspan 68-96mm. Adult males are a dark reddish brown with a small white discal spot on the forewings and there is a diffused yellow median band on all wings. There is a yellow basal patch on the forewings which can be variable. The large heavy females are yellowish brown with similar markings to the male.

Sets:  male upperside female upperside

Flight Period: Late May to early August.

Status: Widespread especially in western and northern counties; less frequent in the east due to the lack of suitable habitat.

Ecology: A species normally associated with heaths and bogs and commonly encountered where suitable habitat exists. Males are often seen flying swiftly and erratically over heathery bogs during the day in sunshine. They fly at night and are attracted to light in small numbers. This species has been traditionally divided into two subspecies; subspecies quercus (Oak Eggar) with a one year lifecycle, flying in July & August in southern England and subspecies callunae (Northern Eggar) with a two year life cycle flying in May and June. However the validity of this has been recently questioned as some specimens with a one year cycle resemble callunae, while others resemble quercus in the males and callunae in the females (Emmet & Heath 1991). It is also evident in Ireland that callunae has a longer flight period than previously thought. The larvae are often seen resting openly on vegetation in the autumn prior to hibernation and throughout the spring and summer of the following year. The pupa is protected inside a tough silken cocoon spun among ground vegetation and can be occasionally found during the winter months. The larvae have been found in N. Ireland feeding on heather; other foodplants include bilberry and bramble.

Bradley & Fletcher number: 1637 Agassiz number: 66.007

Additional information:

UK Moths account


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