First moth species on Alpenrose discovered

Discovery of the first moth species to mine the leaves of the highly poisonous Alpine rose

 Rust-red alpine rose, one of the most popular alpine plants. Photo by Ingrid Huemer

An Austrian-Swiss research team was able to find a previously unknown glacial relic in the Alps, the Alpine rose leaf-miner moth. It is the first known species to have its caterpillars specializing on the rust-red alpine rose, a very poisonous, widely distributed plant that most animals, including moths and butterflies, strictly avoid. The extraordinary record was just published in the peer-reviewed scientific journal Alpine Entomology.

Poisonous host plant

The rust-red alpine rose (Rhododendron ferrugineum) is among the best-known and most attractive plants due to its flowering splendor – at least for humans. It is, in fact, a highly poisonous plant, strictly avoided by grazing animals. For insects, the alpine rose is attractive at most as a nectar plant; insect larvae, on the other hand, develop on it only in exceptional cases. This also applies to Alpine butterflies and moths, which leave Alpine roses largely untouched despite their wide distribution. Therefore, the discovery of a highly specialized species in the Alps came as a complete surprise.

Chance find

Since alpine roses are unattractive to caterpillars and no insect the entire Alpine region was previously known to specialize on them, butterfly and moth experts had considered them rather uninteresting and ignored them in their research. The discovery of the alpine rose leaf-miner wasn’t the result of a targeted search: it was a pure stroke of luck.

During a cloudy spell in July this year, researchers surveying the butterflies in Ardez in the Engadine valley, Switzerland, happened to take a break exactly at an infested alpine rose bush. 

“The accidental sighting of the first caterpillar in an alpine rose leaf was an absolute adrenaline rush, it was immediately clear that this must be an extraordinary species,”

Peter Huemer, researcher and head of the natural sciences department of the Tyrolean State Museums

Peter Huemer, researcher and head of the natural sciences department of the Tyrolean State Museums, and Swiss butterfly and moth expert Jürg Schmid came back in late July and early August to look for caterpillars and pupae and find out more about this curious insect. The extended search yielded evidence of a stable population of a species that was initially a complete enigma. 

Life in the leaf

The alpine rose leaf-miner moth drills through the upper leaf skin and into the leaf interior immediately after the caterpillar hatches. The caterpillar then spends its entire life until pupation between the intact leaf skins, eating the leaf from the inside. Thanks to this behavior, the caterpillar is just as well protected from bad weather as from many predators such as birds, spiders, or some carnivore insects. The feeding trail, called a leaf mine, begins with a long corridor and ends in a large square-like mine section. The feces are deposited inside this mine. When the time comes for pupation, the caterpillar leaves the infested leaf and makes a typical web on the underside or a nearby leaf. With the help of several fine silk threads, it produces an elaborate “hammock”, in which the pupation finally takes place. In the laboratory, after about 10 days, the successful breeding to a moth succeeded, with a striking result.

Enigmatic glacial relic

Final instar larva of the alpine rose leaf-miner moth on Rhododendron ferrugineum in Ardez, Graubünden, Switzerland. Photo by Jürg Schmid

Huemer and Schmid were surprised to find out that the moths belonged to a species that was widespread in northern Europe, northern Asia and North America – the swamp porst leaf-miner butterfly Lyonetia ledi. By looking at its morphological features, such as wing color and pattern, and comparing its DNA barcodes to those of northern European specimens, they were able to confirm its identity.

Habitat of the alpine rose leaf-miner moth in Engadine/Switzerland with Rhododendron ferrugineum. Photo by Jürg Schmid

The Engadine population, however, is located more than 400 km away from the nearest other known populations, which are on the border of Austria and the Czech Republic. Furthermore, the species lives in northern Europe exclusively on swamp porst and Gagel bush – two shrubs that are typical for raised bogs and absent from the Alps. However, the researchers suggest that in earlier cold phases – some 22,000 years ago – the swamp porst and the alpine rose did share a habitat in perialpine lowland habitats north of the Alps. It is very likely that after the last cold period and the melting of the glaciers, some populations of the species shifted their host preference from the swamp porst to the alpine rose. The separation of the distribution areas of the two plants caused by subsequent warm phases inevitably led to the separation of the moth populations. 

Extinction risk

The Alpine Rose Leaf-miner Moth is so far only known from the Lower Engadine. It lives in a steep, north-exposed, spruce-larch-pine forest at about 1,800 m above sea level. The high snow coverage in winter and the largely shady conditions in summer mean that alpine roses don’t get to bloom there. The scientists suspect that the moth species can still be discovered in places with similar conditions in the northern Alps, such as in neighboring Tyrol and Vorarlberg. Since the moth is likely nocturnal and flies late in the year, probably hibernating in the adult stage, the search for the caterpillars and pupae is more promising. However, the special microclimate of the Swiss location does not suggest that this species, which has so far been overlooked despite 250 years of research, is widespread. On the contrary, there are legitimate concerns that it could be one of the first victims of climate change.

Research article:

Huemer P, Schmid J (2021) Relict populations of Lyonetia ledi Wocke, 1859 (Lepidoptera, Lyonetiidae) from the Alps indicate postglacial host-plant shift to the famous Alpenrose (Rhododendron ferrugineum L.). Alpine Entomology 5: 101-106. https://doi.org/10.3897/alpento.5.76930

New to science New Zealand moths link mythological deities to James Cameron’s films

In an unexpected discovery from New Zealand, two species of narrowly distributed moths were described as new species. Interestingly, both Arctesthes titanica and Arctesthes avatar were named after mythological deities and top-grossing blockbusters by famous filmmaker James Cameron: Titanic and Avatar, respectively.


The newly described moth species Arctesthes avatar in its natural habitat (South Island, New Zealand). Photo by Brian Patrick.

In an unexpected discovery from the South Island (New Zealand), two species of narrowly distributed macro-moths were described as new species. Interestingly, both Arctesthes titanica and Arctesthes avatar were named after mythological deities and top-grossing blockbusters by famous filmmaker James Cameron: Titanic and Avatar, respectively.

Each of the newly described species are believed to be restricted to only a couple of subalpine/alpine localities. Therefore, they are particularly vulnerable to extinction and need to be “considered of very high priority for conservation”, point out New Zealand scientists Brian Patrick (Wildland Consultants Ltd), Hamish Patrick (Lincoln University) and Dr Robert Hoare (Manaaki Whenua-Landcare Researchin their paper in the open-access journal Alpine Entomology.


Male (left) and female (right) specimens of the newly described moth species Arctesthes titanica. Photo by Birgit Rhode.

Because of its relatively large size, one of the new discoveries: A. titanica, was named in reference to the Titans: the elderly gods in Greek mythology and the legendary, if ill-fated, record-breaking passenger ship ‘Titanic’, which became the subject of the famous 1997 American epic romance and disaster film of the same name. Unfortunately, the moth’s small wetland habitat is located in an area that is currently facing a range of damaging farming practices, such as over-sowing, grazing, stock trampling and vehicle damage.

On the other hand, A. avatar received its name after Forest & Bird, the New Zealand conservation organisation that was behind the 2012 BioBlitz at which the new species was collected, ran a public competition where “the avatar moth” turned up as the winning entry. The reference is to the indigenous people and fauna in Avatar. Just like them, the newly described moth is especially vulnerable to habitat change and destruction. In addition, the study’s authors note that the original avatars came from Hindu mythology, where they are the incarnations of deities, including Vishnu, for example, who would transform into Varaha the boar.

In conclusion, the scientists point out that future studies to monitor and further understand the fauna of New Zealand are of crucial importance for its preservation:

“Quantitative studies as well as work on life histories and ecology are particularly needed. Already one formerly common endemic geometrid species, Xanthorhoe bulbulata, has declined drastically and is feared possibly extinct: its life history and host-plant have never been discovered. Without further intensive study of the fauna of modified and threatened New Zealand environments, we will be unable to prevent other species slipping away.”

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Original source:

Patrick BH, Patrick HJH, Hoare RJB (2019) Review of the endemic New Zealand genus Arctesthes Meyrick (Lepidoptera, Geometridae, Larentiinae), with descriptions of two new range-restricted species. Alpine Entomology 3: 121-136. https://doi.org/10.3897/alpento.3.33944