Yorkshire Status: Rare and very local resident.
This must be one of our most important species as our population is geographically isolated from other strongholds in the country by a long distance. There have been developments since the 2020 comments below. 2023 was the fifth year of the study of larval webs in the south of VC62, with records coming from 41 sites. Many of these, particularly in the south of the range were new, and three were across the border in VC61. Moths were reared from larvae collected from one site in 2022 and the adults were released in the same place. This study has shed much light on the current status and distribution, and we know now that this species is present in 15 x 10K squares – a far larger area than was originally suspected. The comments below about where the Haxby moth originated from may have been partially answered, as webs have been discovered considerably further south in 2023, so the distribution is apparently quite a bit larger than we have all believed over the last few years.
Sutton & Beaumont, 1989: This species has declined seriously over the whole country over the last few years, Yorkshire now being one of its last strongholds. It can be found at various sites in the Pickering area, where the larval webs are constructed in hawthorn, blackthorn or even dog rose (PQW pers. comm.). It seems to be able to exist in very low, close-trimmed hedges, so should not be in danger unless local farming practices change drastically. The pupae may wait over five or more winters, so that when a good spring arrives there may be a massive emergence resulting in many webs (AMRH pers. comm.).
2020 (CHF): Small Eggar has a very fragmented distribution in England but things were different in the past. Porritt seemed to have little trouble finding it and in 1883 listed several sites in all five VCs, mostly in the centre and east of the county. In 1907 he just listed three localities, Everingham, Ingleby Greenhow and Thirsk where it appeared to be commonest. Perhaps the decline had already started by that time. Further north, there were records into Northumberland and Durham in the 19th century and Dunn & Parrack say the last record for the north-east of England was at Newham Bog in 1896 (incidentally the old Northumberland site for Dark Bordered Beauty) though the Northumberland Moths web site has records for 1899. Either way, it disappeared from localities to our north at an early stage.
Sutton and Beaumont in 1989 mentioned a severe decline across the whole country "over the last few years" and pointed out that the last stronghold in Yorkshire was "in the Pickering area". The map in the new Atlas is interesting, showing how widespread it was in the past and showing the current fragmented populations in the south-west, Oxfordshire area, East Anglia, mid-Wales and south Cumbria, in addition to our own population.
Adult Small Eggar is rarely seen, possibly because of the early flight time of January to March (Field Guide) or February to April (Atlas) at a time of year when most people tend to trap in their gardens rather than venture further afield. The only record on our database of an adult caught at light was one at Haxby in 2007, and I get the impression it is not a moth that wanders widely. It is usually recorded as larvae in webs in hedges - usually blackthorn or hawthorn, and there have been small numbers of records from the Malton and Pickering areas in recent years. The exact distribution has been quite uncertain - until now. Sam Newton has been doing some fantastic work in 2019 and 2020 surveying this area for larval nests and has discovered a huge number of locations. We can really see the proper distribution for the first time. You will notice that the records go up to the Derwent and don't cross into VC61. This doesn't mean that the river forms a boundary and that it doesn't occur in VC61, rather that this area hasn't yet been properly surveyed. I hope the study will continue this year and find more records in this direction.
Poor hedgerow management in the past might have contributed to the decline of this species, as cutting out of season from April to June damages the larval webs. It over-winters as a pupa near the ground but it could be affected as an egg if hedges are cut in February. I was surprised that managed hedges tended to do better than those left to grow unchecked and rarely cut. Sam has been able to draw some interesting conclusions and advice on hedgerow management.
I wonder if this is the full story. Does it occur outside the core area? Why does it just occur in this area? Where did the Haxby moth come from? It is quite a distance for it to fly from the core area and I strongly suspect it occurs a little further south. We have a 1950 record from Allerthorpe Common which of course is not far from where it was not uncommon at Everingham in Porritt's day. It was caught by Denis Wade and I have the specimen in my collection. It is certainly well worth while keeping an eye open for larval webs from late April to early July in hedges anywhere on the east side of the county. Recorded in 28 (14%) of 200 10k Squares. First Recorded in 1883. Last Recorded in 2023. Additional Stats |