Season (Adult / Immature):
National Status: Common
Local Status: Uncommon and thinly distributed or restricted resident.
Local Record: Grade 2 See here for explanation
Flight time: One generation, Sep-Nov.
Foodplant: Blackthorn, Hawthorns, Plum, Cherry, Crab Apple.
|Year first recorded||1805||1883||1883||1883||1883|
|Year last recorded||2014||2014||2013||2014||2013|
|Number of records||329||304||48||476||162|
|Number of individuals||641||450||67||985||280|
For the county, we have a total of 1319 records from 204 sites. First recorded in 1805.
Sutton & Beaumont, 1989: Distributed over all five vice-counties and locally common although possibly under-recorded due to its late flight period. The larvae are sometimes conspicuous and have been recorded on hawthorn and blackthorn in the Scarborough area (PQW pers. comm.).
Current status (CHF, 2011): In decline nationally. A slow reduction in numbers. The moth is no longer resident at Spurn but otherwise the distribution has not altered.
(CHF, 2020): Looking at the chart for Figure of Eight, it’s a moth that’s fallen off a cliff edge. Something horrible has happened to it in Yorkshire since about 1980. At first glance it looks like a flat line from 2000 so I’ve added a chart for just 2000 to 2020 and it proves that it is still going down in numbers at a pretty steady rate. What on earth has happened?
You won’t be surprised to find out that Porritt found it “widely distributed and often common” though he did say it was scarce in some parts of the south West Riding. MBGBI in 1983 said it was “common and widespread” and Sutton and Beaumont didn’t seem too unhappy about the situation in 1989 – “locally common although possibly under-recorded due to its late flight period”. It isn’t just Yorkshire, it’s a national thing. The Atlas says the Rothamsted data from 1970 to 2016 shows a drop in abundance of 96%, but looking at the data, this is nearly all from 1987 as until then it seems to have been doing OK. Noctuidae Europaeae in 2009 said “decreasing markedly in some areas” although it was still “widespread across Europe”, though I see the Dutch were very worried about it in 2011. The drop in numbers in the UK has been accompanied by a decrease in distribution. The loss is patchy but it particularly marked in East Anglia, the Midlands, Yorkshire and Northumberland. There is some spread to a higher altitude and Yorkshire data shows a rise of 1.6m in altitude per year (52 to 85m in 20 years). It therefore isn’t as clear-cut a case of deserting the lowlands that we see in some species, but it’s a tendency in that direction. Climatic change is probably playing a part but it isn’t the full story, and if it really is playing a part, it is making the moth head for more upland locations but not spread north, so perhaps it is a change in farming practices in the lowlands and nothing to do with climate.
Looking at current trends, we still get records fairly regularly from one or two sites: Otley, the Ripon area (including my garden now and again), and parts of eastern VC62. Nine records in 2020 was better than the all-time low of four in 2019 and included new sites at Stokesley and Great Barugh. There have been only two records in VC63 since 2000 so this rather backs up Porritt’s observations. Is some of the problem to do with habitat? It is difficult to find out exactly what it needs, but the larvae feed on blackthorn, hawthorn, crab apple and various others. The Field Guide says “sunny situations but also shady situations”, so that’s a lot of use. It overwinters as an egg on the foodplant, so it must suffer hugely from annual winter hedge cutting. I’m sure I read somewhere that straggly old hawthorn thickets were the best place but I can’t find the reference. My own hedges are cut annually, but I have one long uncut hawthorn/blackthorn hedge forming a barrier between me and next door which might be a source of my moths. One German web site says it’s in decline in many places north of the Alps, due to “uniformisation of the landscape (removal of bushes and hedges, modern agriculture) and the dark forest management without clearings and bushy edges” which sound pretty sensible. It’s rather a parallel with the decline of Lackey which currently isn’t quite so dramatic, but hedgerow management might be a factor there as well.
It’s a lovely moth and I’m always really pleased when I see it in my moth trap in October, or often on the sheet. It would be sad if it disappeared. It’s scientific name, caeruleocephala or “blue-headed” you might not be aware refers to its larva although its head is grey and by no stretch of the imagination caerulean. Classic scholars will like the fact that it is a combination of a Latin first half and a Greek second half, which is why we never refer to “Latin” names. It’s a bit like Grimston hybrids in Yorkshire place names – half Viking and half Anglo-Saxon. The genus, Diloba, invites you to compare “two ear lobes” with the wing markings. I reckon this is a much better description than the vernacular name. It looks like 88 to me anyway.
Finally, don’t get your Figure of Eight and your Figure of Eighty mixed up. We get several records of “Figure of Eight” every year in July!