Friday, 12 July 2019

Alpine Longhorn Beetle - a dream comes true

Some animals are so charismatic, yet so elusive or rare, that the wish to see them escalates on every failed encounter. Sometimes they haunt you for years and you never seem to be lucky, no matter how much you try. For us this was the case with the beautiful Alpine Longhorn Beetle or Rosalia Longicorn Rosalia alpina, which until a few days ago, proved to be a mythical beast. This impressive longhorn beetle of the Cerambycidae family is rare on a European level and listed as vulnerable (VU) by the IUCN. Needles to say it is also a Natura 2000 species for which some special protection sites have been designated in Slovenia. Its life cycle is linked to the beech Fagus sylvatica and thus it is mainly found in mountain beech forests, especially those in warmer, sunnier areas of the Alps, but also other mountain and hilly areas of central and southern Europe. In Slovenia it is found in different regions, but nowhere in large densities. It is somewhat commoner in the Julian Alps, some parts of the Dinaric mountains and in some wooded hills of the Štajerska region. The essential element in its habitat is dead beech wood. Males and females are especially attracted to freshly wounded trees, but also cut timber and log piles. Apparently the smell of wounded beech wood proves irresistible to them. The easiest way to look for an Alpine Longhorn Beetle (but also other species of Cerambycidae, like the Beech Longhorn Beetle Morimus funereus for example) is to carefully check beech log piles in deciduous forests in July and August. 
A few days ago we visited the Trenta valley at the heart of the Triglav National Park in the Julian Alps, with the intention to look for this rare longicorn. This time we were finally successfull as we found a nice log pile at the side of a road, where up to 5 stunning Alpine Longhorn Beetles were sunbathing!
Alpine Longhorn Beetle Rosalia alpina

The adult Alpine Longhorn Beetles emerge in summer and can be seen basking in the sun, mating or depositing the eggs on the logs. Sadly these log piles act as traps as they are taken away from the forest, with whole broods of longhorn beetles, which are subsequently destroyed during the industrial processing of the timber. A simple measure to avoid this would be to quickly remove the logged trees from the forest, before the beetles could lay their eggs in them. Another measure to help longhorn beetles is to leave some log piles in the forest without removing them. This is exactly what the Triglav National Park has done recently by placing a permanent log pile and an info board about the Rosalia Longicorn along a tourist trail in the Trenta valley. Now in the summer months visitors can read about this rare beetle and with a bit of luck, spot one basking on the logs. After finding our own longicorns at another site, we also payed a visit to this demonstration log pile called Rosalium, where amazingly 3 more Alpine Longhorn Beetles were there for all the visitors to enjoy. Very didactic!
The "Rosalium"
A tame Alpine Longhorn Beetle Rosalia alpina decided to land on my hand. Yes, the can fly!


The longhorn beetles could have been enough to make our day, but the Trenta valley provided some other interesting wildlife. Among birds we saw several Crag Martins Ptyonoprogne rupestris and heard a Western Bonelli's Warbler Phylloscopus bonelli, while butterflies of note included Styrian Ringlet Erebia stirius, Mountain Green-veined White Pieris bryoniae, Chalkhill Blue Lysandra coridon and Arran Brown Erebia ligea.
We were also very glad that Mitja Denac gave us a tip on where to see Creeping Lady's-tresses Goodyera repens - a tiny orchid sprouting in summer under conifer trees. It was a lifer for us! Finally we also enjoyed in seeing good numbers of the rare Tufted Horned Rampion or Devil's Claws Physoplexis comosa, although they weren't in full bloom anymore.
Chalkhill Blue Lysandra coridon
Styrian Ringlet Erebia stirius
Creeping Lady's-tresses Goodyera repens (thanks to Mitja Denac!)
Tufted Horned Rampion Physoplexis comosa
Yellow Bird's-nest Monotropa hypopitys
Dark-red Helleborine Epipactis atrorubens
Hairy Alpenrose Rhododendron hirsutum
Mountain views from the Trenta valley.

Sunday, 7 July 2019

Rare butterflies in Trnovski gozd

Some days ago we visited one of Slovenia's butterfly hotspots, the southern edge of Trnovski gozd (the Trnovo forest). This is an area of dry mountain meadows at an altitude between 1000-1200 meters above the sea, bordered by the mixed Dinaric forests of the Trnovo plateau. The area is so rich with butterflies (but also floristically diverse) because it lays right along the Dinaric ridge, which represents a meeting point of different biogeographical regions. Here plants and animals typical of the Mediterranean mix with those from the continent, the Alps and the Balkans.
During our visit we observed 35 species of butterflies, many of which were interesting, scarce or locally rare species. We were mostly excited by the find of several Apollos Parnassius apollo, one of Slovenia's rarest and most endangered butterflies (see last year's post), but also other local specialities like Styrian Ringlet Erebia stirius, Great Sooty Satyr Satyrus ferula and Clouded Apollo Parnassius mnemosyne. This time we were so excited that we even wrote a complete butterfly check-list of the trip - you can find it at the end of the post.
Apart from butterflies we enjoyed in the carpets of flowering mountain plants, including many rare ones like White Sainfoin Onobrychis alba, Grass-leaved Scabious Scabiosa graminifiolia, the endemic Hladnikia Hladnikia pastinacifolia (only found in Trnovski gozd and nowhere else), Carniolan Lily Lilium carniolicum, Spiked Bellflower Campanula spicata, Carniolan Vetch Astragalus carniolicus and many many others. Among birds the most interesting sights were all from the road: 3 Short-toed Eagles Circaetus gallicus (2 near Sežana and 1 near Vipava) and a fly-by Hoopoe Upupa epops in the Vipava valley. In the dry mountain meadows Rock Buntings Emberiza cia were most prominent.

Mountain meadows above the Vipava valley.
Apollo Parnassius apollo. We observed at least 4 different.
Some say the "eye" markings on the Apollo's wings were the main inspiration for the colour signs that are used in Slovenia for marking mountain paths.
Great Sooty Satyr Satyrus ferula.   
A localised species of dry rocky places along karstic ridges in western Slovenia.
Styrian Ringlet Erebia stirius.  
 An alpine species with isolated populations in the Dinaric mountains 
(Trnovski gozd, Nanos and Kočevsko).
Arran Brown Erebia ligea
Queen of Spain Fritillary Issoria lathonia
Great Banded Grayling Brintesia circe
Lesser Spotted Fritillary Melitaea trivia
Assman's/Nickerl's Fritillary Melitaea britomartis/aurelia
Marbled White Melanargia galathea
High Brown Fritillary Argynnis adippe
Pearly Heath Coenonympha arcania
Black-veined White Aporia crataegi
Grayling Hipparchia semele
Silver-washed Fritillary Argynnis paphia (dark form valesina)
Brimstone Gonepteryx rhamni
Spiked Bellflower Campanula spicata
Rock Bunting Emberiza cia


Complete butterfly check-list of the day (not in systematic order) - tot. 35 species:

Blue-spot Hairstreak Satyrium spini
Marbled White Melanargia galathea
Pearly Heath Coenonympha arcania
Small White Pieris rapae
Silver-washed Fritillary Argynnis paphia
Styrian Ringlet Erebia stirius
Heath Fritillary Melitaea athalia
Chestnut Heath Coenonympha glycerion
Scarce Swallowtail Iphiclides podalirius
Common Swallowtail Papilio machaon
Queen of Spain Fritillary Issoria lathonia
Brimstone Gonepteryx rhamni
Lesser Spotted Fritillary Melitaea trivia
High Brown Fritillary Argynnis adippe
Large Wall Brown Lasiommata maera
Painted Lady Vanessa cardui
Spotted Fritillary Melitaea didyma
Large Skipper Ochlodes sylvanus (venatus)
Peacock Aglais io
Great Banded Grayling Brintesia circe
Clouded Apollo Parnassius mnemosyne
Grayling Hipparchia semele
Mazarine Blue Cyaniris semiargus
Common Blue Polyommatus icarus
Arran Brown Erebia ligea
Meadow Brown Maniola jurtina
Assman’s/Nickerl’s Fritillary Melitaea britomartis/aurelia
Black-veined White Aporia crataegi
Small Blue Cupido minimus
Large White Pieris brassicae
Apollo Parnassius apollo
Large Chequered Skipper Heteropterus morpheus
Duke of Burgundy Hamearis lucina
Great Sooty Satyr Satyrus ferula
Scotch Argus Erebia aethiops

Read more about Slovenian butterflies and their diversity on our website: Butterflies of Slovenia.

Tuesday, 2 July 2019

Early summer butterflies

During these warm summer weeks, butterflies have become our main focus. Despite the fact we were quite busy with other work recently, we still managed to visit a few nearby places and see several interesting species. The best find of all was a Poplar Admiral Limenitis populi we had the chance to admire up close in the forests of the Snežnik plateau. This is a rare species in Slovenia, living in mountain forests where aspen Populus tremula, its larval foodplant, is present.
Our garden in the Karst is also hosting a good number of butterflies as they come to feed on our lavenders on a daily basis. We've also began to see the first Stag Beetles Lucanus cervus flying around the garden at dusk. Last week we also enjoyed the company of some Swiss friends to whom we showed a fabolous pair of Ural Owls Strix uralensis as well as several other birds around lake Cerknica.
Poplar Admiral Limenitis populi, Snežnik plateau.
Aspen Populus tremula, Snežnik plateau. The Admiral's larval foodplant.
Hunting butterflies, Snežnik plateau.
Chestnut Heath Coenonympha glycerion, Snežnik plateau.
Woodland Brown Lopinga achine, Snežnik plateau. 
A very common species in the Dinaric forests.
Heath Fritillary Melitaea athalia, Snežnik plateau.
Justin's Bellflower Campanula justiniana, Planina. 
An endemic species of the Dinaric mountains, from central Slovenia to NW Croatia.
Orange Lily Lilium bulbiferum, Snežnik plateau.
Ural Owl Strix uralensis, Snežnik plateau (phone-scoped).
Silver-washed Fritillary Argynnis paphia, Karst. 
Very common butterfly at the moment.
Large Chequered Skipper Heteropterus morpheus, Karst.
Large Skipper Ochlodes venatus (sylvanus), Karst.
Scarce Swallowtail Iphiclides podalirius, Karst.
Meadow Brown Maniola jurtina, Karst.
Great Banded Grayling Brintesia circe, Karst. 
One of the commonest butterflies in the Karst at the moment.