By Russell Wynn, 10 July 2016
The New Forest is recognised as one of the premier sites in the UK for insects, including a number of nationally rare and scarce moth species. I have regularly run a moth trap in the New Forest since 2004, initially at the coast near Lymington, and from 2007 onwards in my garden on the southern outskirts of Brockenhurst adjacent to Setley Plain. This effort has produced nearly 750 species to date, with both gardens attracting over 300 of the larger ‘macro moth’ species in a single year!
Some of the highlights include rare or vulnerable moths that are Red Data Book listed, including Triangle, Dingy Mocha, Portland Ribbon Wave, Southern Chestnut, Scarce Merveille du Jour, Light Crimson Underwing, Dark Crimson Underwing, Olive Crescent and Mecyna flavalis. Several others are classified as Nationally Scarce A (i.e. recorded in less than 30 ten kilometres squares in the UK), including Small Grass Emerald, Bordered Grey, Ringed Carpet, Small Black Arches, Mompha divisella, Acleris umbrana and Ancylis subarcuana. Many of these are specialists of ancient oak woodland or open heath / bog habitats, which are a key component of the New Forest.
In addition to rare resident species, I have also been lucky enough to catch some spectacular migrant moths, including the second Hampshire record of Lunar Double-stripe near Lymington in 2006, and the fifth record of Beautiful Marbled at Brockenhurst in 2012. Other notable migrants have included Blair’s Mocha, Convolvulus Hawk-moth, Scarce Bordered Straw, Small Marbled, Diasemiopsis ramburialis, Palpita vitrealis, Conobathra tumidana and Cydia amplana (which may have temporally become established near Brockenhurst).
There have also been some new colonists, with my garden near Lymington containing holm oaks that supported a colony of the rare Oak Rustic, and my current garden in Brockenhurst producing annual records of the spectacular Blue Underwing (also known as Clifden Nonpareil), which feeds on poplars; the latter is one of the most prized moths to occur in the UK, so having one of very few established UK populations nearby is quite fortunate!
In 2015 I did very little moth trapping due to other commitments, so I was determined to renew my efforts in 2016. However, the inclement weather through the late winter and early spring meant that there were few opportunities for trapping, and it wasn’t until early May that things really took off (although see our earlier blog post for an account of our search for the rare Sloe Carpet in April).
The first wave of notable species in my Brockenhurst garden occurred in the period 6-11 May, with the highlight being a specimen of Dingy Mocha on 7 May. This is one of 81 UK moth species that are listed as conservation priorities in the UK Biodiversity Action Plan. Also of note were a couple of Marbled Pugs, supported by Water Carpet, Little Thorn, Scarce Prominent and Red Sword-grass. Towards the end of this period I also recorded my first migrants of the year, in the form of Rush Veneer and Dark Sword-grass.
A quieter spell then ensued, although the first Rosy Marbled appeared on 26 May, followed the next day by Ancylis upupana and on 1 June by Elegia similella.
The next wave of scarce species came in the period 5-12 June, with the first date producing a pristine Scarce Merveille du Jour. Other notables included Great Oak Beauty, Puss Moth, Cream-bordered Green Pea, Eudonia delunella and the first migrant Silver-Y moths of the year.
However, this period was most notable for the massive influx of Diamond-back Moths recorded across the UK, which featured in national media. These tiny moths had been blown into the country by the persistent east and northeast winds in early June, and peak numbers in my garden arrived in the period from 3-10 June, with a peak of 42 on 8 June.
The final record of note was a female Gem on 27 June, which is a scarce but regular migrant from the continent. So up to the end of June, at the halfway point of 2016, I have recorded 164 macro moth species and 69 micro moth species. I’ll provide another moth update later in the season, but for now let’s hope for some warm, settled weather!