Yorkshire Status: Thinly distributed or restricted resident.

Both subspecies of this moth seem to be doing well. Northern Eggar (ssp callunae) in upland areas of the west and north of the county, and Oak Eggar (ssp quercus) in central and south-eastern areas. Sutton and Beaumont (below) suggest that Northern Eggar, which tends to have a two-year life cycle, emerges in odd-numbered years, but there is little evidence of this in recent years. Like several related species, males tend to fly by day on sunny afternoons, whilst females fly at night and may come to moth traps.Despite the name, Oak Eggar has no association with oak. The name is because of a rather fanciful similarity between the cocoon and an acorn!


Sutton & Beaumont, 1989: There are two subspecies of this moth, ssp. callunae (Palmer), the Northern Eggar and ssp. quercus (Linnaeus), the Oak Eggar. The main difference are in habitat preferences and phenology, callunae has a two year life-cycle whilst quercus completes its growth in a single year. In Derbyshire Harrison and Sterling (1986) comment that in callunae (the most frequent of the two) the adult insects are only found in odd-numbered years. In Yorkshire this seems to be the case in the west (see Kettlewell, 1973 for example), however in the North York Moors adult insects are recorded in both odd and even years, although there have been no indications of numbers involved so it may be that the majority are synchronised in odd-number years. Yorkshire records which distinguish between the two suggest that quercus is only found in the south-east of the County (Spurn Point, VC61, and possibly Hatfield Moor, VC62). Callunae is common on high moors and lowland mosses throughout vice-counties 61-64, although not recorded from VC65 there seems to be no reason why it should not be present.

Recorded in 126 (63%) of 200 10k Squares.
First Recorded in 1804.
Last Recorded in 2023.
Additional Stats