Lochaline Field Trip For Blomer's Rivulet, 22nd June 2014

Pete Moore

 

Last year, on 14 June 2013, Mary Eagleson, taking part in a BC Highland branch field trip, found a Blomer’s Rivulet at Lochaline on the Morvern peninsula. This was accepted as the first record of this species for Scotland.

 

Another branch field trip was organised for this June, 2014, to confirm the presence of Blomer’s Rivulet in the area and if possible get an idea of how numerous and how widespread it is in the area.

 

On 21 June 2014, five moth traps were run overnight near Lochaline - all near to wych elms, the foodplant of Blomer's Rivulet. Continuous woodland runs along both western and eastern shores of Loch Aline so three traps were set on the western side and two traps on the eastern side. The Blomer’s Rivulet seen last year was at the southern tip of the western side woodland. 

 

The following morning, a small group of Highland branch members went through the traps. An actinic set close to where Blomer’s was seen last year mysteriously had no moths in it at all. However, an MV trap 800m further along the western shore woodland held 20 Blomer’s and an MV trap a further 900m along (i.e. 1.7km from the site of last year’s site) held 10 Blomer’s.

 

The two traps on the eastern side of the loch held no Blomer’s, which was surprising. One MV trap on the east side was just 500m from the site of last year’s record, albeit on the opposite side of the loch. 

 

Further trapping will be required to understand the full extent of Blomer’s in the Lochaline area. However, this year’s trip has confirmed the presence of Blomer’s in this area and learned that there is a healthy but probably quite restricted population of Blomer’s Rivulet at Lochaline. The numbers of wych elm within the woodland seem to dwindle as one moves northwards along the shore, which may account for the lower numbers seen in the more northerly MV trap. But with 20 and 10 individuals within the two traps respectively, it was one of the most numerous species of moth in the traps.

 

Amazingly, around the time of this visit to Lochaline, Julie Stoneman and Doug Gilbert discovered Blomer’s Rivulet whilst moth-trapping at Invermoriston – 65 miles away from Lochaline!! This surprise discovery of a second site brings into focus the question of how long Blomer’s Rivulet has been in Scotland – has it simply been overlooked and now discovered by chance or is it spreading and increasing in numbers?

 

Further targeted trapping of areas of wych elm, especially in the west of Scotland, should add more pieces to the Blomer’s Rivulet puzzle!

 

Naturally, lots of other moth species were found in the field trip traps along with Blomer’s Rivulet – 78 species in all – 64 macro-moths and 14 micro-moths. A good night’s trapping!!

 

Full moth list below:

 

Macros
Barred Red	Beautiful Brocade	Beautiful Golden Y
Blomer's Rivulet	Bright-line Brown-eye	Brimstone Moth
Broom Moth	Brown Rustic	Brussels Lace
Buff Ermine	Buff-tip	Campion
Clouded Border	Clouded Brindle	Common Carpet
Common Lutestring	Common Rustic agg.	Common Wave
Common White Wave	Coronet	Coxcomb Prominent
Double Square-spot	Drinker	Dusky Brocade
Elephant Hawk-moth	Flame Shoulder	Foxglove Pug
Gold Swift	Green Arches	Green Carpet
Grey Arches	Grey Pug	Heart and Dart
Iron Prominent	Large Yellow Underwing	Light Emerald
Lychnis	Map-winged Swift	Middle-barred Minor
Mottled Beauty	Oblique Carpet	Pale Prominent
Pale-shouldered Brocade	Peach Blossom	Peacock Moth
Pebble Prominent	Peppered Moth	Poplar Hawk-moth
Purple Clay	Riband Wave	Sandy Carpet
Satin Beauty	Scalloped Hazel	Silver-ground Carpet
Small Angle-shades	Small Dotted Buff	Small Fan-foot
Small Phoenix	Small Square-spot	Smoky Wainscot
Spectacle	Tawny-barred Angle	True Lover's Knot
White Ermine
Micros
Agriphila selasella	Agriphila straminella	Anania fuscalis
Argyresthia conjugella	Celypha lacunana	Chrysoteuchia culmella
Epiblema uddmanniana	Eucosma cana	Beautiful China-mark
Barred Fruit-tree Tortrix	Platyptilia gonodactyla	Scoparia ancipitella
Udea olivalis