Wednesday, 1 November 2023

Talking molluscs

Heading into autumn, moth-trapping along with general garden listing has started to slow down. As such I have started to turn my attention towards a TAXA group which I have previously only made the slightest of forays into exploring. Molluscs seem the obvious choice as conditions get wetter and cooler, and searching for them on damp nights when the moth trap is not running, maintains my curiosity, and scratches the "listing itch" at the same time.

Noting an interesting looking green and yellow slug on the wall, one night, towards the end of September, I thought it was potentially different to the Green Cellar Slug (Limacus maculatus) that I have recorded before. A long pale stripe running along the keel and tail, was not a feature that from memory I had noted on the few Green Cellar Slugs, I had already identified in the garden.

Having consulted the AIDGAP guide to the “Slugs of Britain and Ireland” (2014) I thought it might be a reasonable candidate for Yellow Cellar Slug (Limacus flavus); with a heavy dose of scepticism given that guide advises that dissection is often required to distinguish it from L. maculatus.
Limacus flavus

Posting the record on iRecord, I was surprised by the almost immediate verification of the species as L. flavus by Chris du Feu who also commented: “Thanks for the record. There is a long enough yellow streak from tail most of the way along the centre of the back to the mantle. It is likely to be a cross between L. maculatus and L. flavus. With L. maculatus being the dominant species at present, it is likely that these crosses become more and more like L. maculatus with each passing generation. Good to see a record which we can call L. flavus. They are becoming something of a rarity now.”

This prompt and considered response from Chris gave me no end of encouragement to pursue the trail (pun intended) of further garden molluscs. Over the next couple of weeks armed with the AIDGAP guides for both slugs and land snails, I stalked the garden looking for likely suspects.

Girdled Snail
(Hygromia (Hygromia) cinctella)


Kentish Snail (Monacha (Monacha) cantiana)

White-lipped Snail (Cepaea (Cepaea) hortensis)

Common Garden Snail (Cornu aspersum)



Large Red Slug (Arion (Arion) rufus)

Large Red Slug in cop.


Draparnaud's Glass Snail (Oxychilus (Oxychilus) draparnaudi)


Netted Field Slug (Deroceras (Deroceras) reticulatum)

Ambigolimax agg.

At work a colleague and I were felling small trees on the heathland. I became very excited to note several Tree Slug (Lehmannia marginata) along the length of a downed Birch (Betula sp.), and we carefully avoided killing them as the cord wood was cut and stacked.
Tree Slug


References

Cameron, R. (2008) 2nd Edition Land Snails in the British Isles AIDGAP Field Studies Council
Rowson, B., Turner, J., Anderson, R., Symondson, B., (2014) Slugs of Britain and Ireland AIDGAP Field Studies Council

Friday, 22 September 2023

Mothing and moth trap intruders .. Isle of Man pt. 2

We leave tomorrow, and it is too early a start on the day - to want to trap again overnight tonight. Over this past week, the traps have yielded less species than I would have hoped for given the location.

The cottage has large gardens, laid out both formally with lawns and hedges, but also has a variety of native trees and shrubs, unkempt wilder areas, and is adjacent to the Killane River which has native wildflower and fern species upon its banks. The surrounding fields are relatively small with good connectivity in the hedgerows.

I used the 25W blacklight or 20W actinic in conjunction with the Skinner Trap, in the back garden. Trapping by porchlight only in the front garden.

Despite the lack of variety, I have still seen some moth species for the first time, adding them to the “life-list” along with a couple of beetles which also came to the light, and of whom I have not seen before either.

The final species tally on the week’s trapping list is as follows:

Moths

Snout (Hypena proboscidalis)
Canary-shouldered Thorn (Ennomos alniaria) Porchlight only
Canary-shouldered Thorn

Common Marbled Carpet (Dysstroma truncata)
Alucita hexadactyla Porchlight only
Brimstone Moth (Opisthograptis luteolata)
Setaceous Hebrew Character (Xestia c-nigrum)
Pink-barred Sallow (Xanthia togata) new for me
Pink-barred Sallow

Angle Shades (Phlogophora meticulosa)
Square-spot Rustic (Xestia xanthographa)
Pearly Underwing (Peridroma saucia)
Beautiful Plume (Amblyptilia acanthadactyla)
Red-green Carpet (Chloroclysta siterata)
Blastobasis lacticolella new for me
Blastobasis lacticolella

Green-brindled Crescent (Allophyes oxyacanthae)
Large Yellow Underwing (Noctua pronuba)
Autumnal Rustic (Eugnorisma glareosa) new for me
Autumnal Rustic

White-shouldered House-moth (Endrosis sarcitrella)
Epiphyas postvittana
Green Carpet (Colostygia pectinataria)
Dark Sword-grass (Agrotis ipsilon)
Lunar Underwing (Anchoscelis lunosa)
Black Rustic (Aporophyla nigra)
Flounced Rustic (Luperina testacea)
Ypsolopha parenthesella new for me
Ypsolopha parenthesella

Beetles

Black Vine Weevil (Otiorhynchus sulcatus)
Chrysolina bankii new for me
Chrysolina bankii

Nabria sp.
Nicrophorus investigator
Acrosus rufipes new for me
Acrosus rufipes

Harvestman

Leiobunum blackwalli new for me
Leiobunum blackwalli

Bugs

Green Shieldbug (Palomena prasina) Porchlight only
Birch Shieldbug (Elasmostethus interstinctus)

Caddisfly

Limnephilus lunatus
Limnephilus auricula
Stenophylax permistus
Halesus radiatus

Cranefly

Tipula paludosa

BWARS

Netelia cristata new for me

Thursday, 21 September 2023

Red-necked Wallaby (Notamacropus rufogriseus L.), Ballaugh Curragh .. Isle of Man pt. 1


Royal Fern (Osmunda regalis) was frequently encountered


the pathways followed the old field boundaries


bog within the wet woodland

Bogbean (Menyanthes trifoliata)

Marsh Cinquefoil (Potentilla Palustris

Red-necked Wallaby scat

Red-necked Wallaby tracks

Red-necked Wallaby

Red-necked Wallabies



Wednesday, 7 June 2023

Spotted in the garden!

Common Spotted Orchid
(Dactylorhiza Fuchsii)

How I managed to miss the Common Spotted Orchid rosette in the back garden for so long beggars me. I have been religiously keeping an eye on the Bee-orchid (Ophrys apifera) rosettes five of which were showing over the late winter, but all of whom failed to throw up a flower spike this year.

However, I did manage to overlook it, that is until the 18th of May, by which time it was quite a substantial plant – growing within a foot of the patio, and only three feet away from the garden bench. We went to the Isle of Man, and when we got back it was coming into flower.

My understanding is that this specie takes three to four years from seed set to a flowering plant, and only if the right mycorrhizal fungi are present in the soil. If this plant sets seed, I will be sprinkling a little of its “fairy dust” around the rest of the back garden, in the hope of developing a new colony. Some seed may also find its way to the front lawn.

Wednesday, 17 May 2023

Cacoxenus indagatar (L.) .. the great escape artist

Bee hotels provide me with endless enchantment – from the first hatchings of the new bees in spring, to the constant hum and movement of the adults as they prepare their nest tubes and lay down the next generation.

I have several types of bee hotel, lying along the length of a low brick wall. Two of the shop bought variety, filled with bamboo cane, which have steadily disintegrated with constant weathering. A solid wood, “bee-hive” with removable shelves, and a set of three short birch logs, whose ends I drilled.

I was unsure how the birch logs would fare, having put them out for the first time this year. They were occupied almost immediately by nest hungry Osmia bicornis.

Part way through May, O. bicornis numbers were building up and all the hotels were being utilised. I also noticed a handful of small flies, on and around the brick wall, sitting on the edges of the bee hotels, and flying in and out of the bamboo tubes.


I posted some images of the fly on the UK Diptera Facebook Group, asking for an identification.

Cacoxenis indagatar

It did not take long before the fly was confirmed as Cacoxenus indagatar. This species is a cleptoparasite of mason bees. It lays its eggs in the nest cells of the host, and when its larvae hatch, they feed on the pollen laid down by the mason bee. As a result, the bee larvae might starve to death – or even get eaten by the fly larvae, should numbers or size of pollen store dictate.

To escape the cell walls of the O. bicornis the adult fly, has a neat trick. It can inflate its head, to force a breach in the wall, a feat it may have to undertake several times to escape along the length of a nest tube. Hence it earns its vernacular as The Houdini Fly!

New Scientist [Online] has a video of the great escape artist in action:


I do not have any literature on UK Diptera so have resorted to online sources only for this post:


New Scientist (ibid)



Addendum

The bamboo hotels have now been repaired with roofing felt to ensure they remain water-tight, and to hold the framework in place.