A provisional checklist of European butterfly larval foodplants

For the first time, a list of the currently accepted plant names utilised by 471 European butterfly larvae is presented, with references.

Guest blog post by Harry E. Clarke, Independent Researcher

5th instar Swallowtail larvae feeding on Milk-parsley.

Many books on butterflies publish lists of their larval foodplants. However, many of these lists of larval foodplants have been copied from previous lists, which in turn have been copied from previous lists. Consequently, errors have crept in, and many plant names have long been superseded. This can result in duplicates in the list, with the same plant being given two different names. Most plant lists do not include the authority, which can make it difficult or impossible to identify which plant is being referred to. Some of these plants may not be used by butterflies in Europe, but elsewhere in their range. Or the plants may have been used in breeding experiments, but not used by the butterflies in the wild.

Many of these publications providing the larval foodplants of butterflies only provide the binomial name, without specifying the author. This can create problems in knowing which species of plant is being used, as the same plant name has been used in the past by different authors to describe different species. In some cases, distribution can be used to determine the correct species, but plants can often have similar distributions. For example, in the World Checklist of Vascular Plants, there are 40 entries for the plant with the scientific name Centaurea paniculata, which refer to thirteen different accepted species, depending on authors, subspecies, and variety or form.

Not quite so simple: updating the current lists of larval foodplants

With climate change and habitat loss threatening numerous species, the conservation of butterflies (and other animals) is becoming more important. Whilst many factors determine the distribution of butterflies, such as temperature and rainfall, their survival depends solely on the kinds of plants their larvae eat. Accurate lists of larval foodplants are therefore important to find out where to direct limited conservation resources for the best result.

What started out as a straightforward job of updating the existing lists of larval foodplants with currently accepted names turned out to be a far bigger job. Many of the lists are incomplete, and may vary throughout the range of the butterfly. Here, errors have crept in too. Many references provide incomplete, unverifiable information. Many species of butterfly lay their eggs off-host, rather than on the host plant. For example, the Silver-washed Fritillary (Argynnis paphia)oviposits on tree trunks above where Viola species are growing. Consequently, oviposition records need to be treated with caution, depending on the species.

What do butterfly larvae eat, and why does it matter?

Butterfly larvae can be very fussy about which plants they can use. 20% of European butterfly larvae are monophagous, feeding on just one species of plant. 50% are oligophagous, feeding on a few different closely related plants, whilst 30% are polyphagous feeding on plants in many different families. The Holy Blue (Celastrina argiolus) can utilise plants in an astonishing 19 different families.

The oligophagous butterflies can be divided into two groups:

  • Oligophagous-monophagous (OM) – feeding on one plant species in one region, and another species in another region.
  • Oligophagous-polyphagous (OP) – feeding on several closely related species of plants throughout their range, usually in the same genus, or a closely related genus.
4th instar Small Tortoiseshell feeding on Common Nettle.

Plant preferences are only known for a few species of butterflies. For example, the English race of the Swallowtail (Papilio machaon) feeds on Milk-parsley (Peucedanum palustre), whereas in the rest of Europe it has been recorded on 62 other plants. The main larval foodplant of the Small Tortoiseshell (Aglais urticae) is Common Nettle(Urtica dioica), although it will occasionally use other plants.

The survivability of larvae on different plants is largely unknown, except in a few cases where the butterfly species has been studied in detail. There are plants that larvae may be able to eat, but that would likely not help them survive to pupation.

Two species are known to switch their larval foodplant during their second year of development. The Scarce Fritillary (Euphydryas maturna),for example, switches from Ash (Fraxinus excelsior) to Guelder-rose (Viburnum opulus). The Northern Grizzled Skipper (Pyrgus centaureae) switches from Dwarf birch (Betula nana) to Cloudberry (Rubus chamaemorus).

The most delicious plants

For the first time, a list of the current accepted plant names utilised by 471 European butterfly larvae is presented, with references. Where possible, errors in previous lists have been removed. The list of larval foodplants doubled compared to previous published lists. This has resulted in a list of 1506 different plant species in 72 different families. 86 plant records are only known at the generic level. Larval foodplants of 25 butterfly species are currently unknown, which are mostly the “Browns” (Satyrinae), which probably feed on grasses (Poaceae), or possibly sedges (Cyperaceae).

Whilst most plant families are utilised by less than six butterfly species, a few plant families are particularly favoured, with grasses (Poaceae) and legumes (Fabaceae) being the most popular. Similarly, most plant species are only utilised by a few butterfly species, but the fine grasses Sheep’s Fescue (Festuca ovina) and Red Fescue (Festuca rubra) are favoured by a large number of butterfly species.

Taxonomic splits create problems. Where cryptic species are allopatric, records can be allocated on the basis of their distribution. But where cryptic species are sympatric, this will require a resurvey to determine the larval foodplants. It cannot be assumed that two cryptic butterfly species use the same plants, as something has to become different for them to evolve into separate species.

Looking forward

Future publications should ensure that old and ambiguous plant names are not used. Plant names should be specified with their full scientific name, as specified by the International Code of Nomenclature for algae, fungi, and plants. The World Checklist of Vascular Plants should be checked to ensure the currently accepted plant name is being used.

Fully documented records are needed of what larval foodplants butterfly larvae are utilising in the wild. To get a better understanding of usage, full details need to be recorded, including date, location, altitude, abundance, and larval stage. Abundance will help in the understanding of preferences. To allow records to be properly verified, evidence should be provided on how the larvae and plants were identified. Regional lists are also important – to help direct conservation efforts to the plants being used locally, rather than elsewhere. This list of larval foodplants is provided as a step towards a fully justified database, which will be updated as and when corrections are found. It highlights those 25 butterfly species whose larval foodplants are currently unknown.

4th instar Chequered Skipper (Carterocephalus palaemon) larvae feeding on Purple Moor-grass (Molinia caerulea).

Research article:

Clarke HE (2022) A provisional checklist of European butterfly larval foodplants. Nota Lepidopterologica 45: 139-167. https://doi.org/10.3897/nl.45.72017

The first Red List of Taxonomists in Europe is calling for the support of insect specialists

The Red List of Taxonomists portal, where taxonomy experts in the field of entomology can register to help map and assess expertise across Europe, in order to provide action points necessary to overcome the risks, preserve and support this important scientific community, will remain open until 31st October 2021.

About 1,000 insect taxonomists – both professional and citizen scientists – from across the European region have already signed up on the Red List of Taxonomists, a recently launched European Commission-funded initiative by the Consortium of European Taxonomic Facilities (CETAF), the International Union for Conservation of Nature (IUCN) and the scholarly publisher best-known for its biodiversity-themed journals and high-tech innovations in biodiversity data publishing Pensoft.

Insect taxonomists, both professional and citizen scientists, are welcome to register on the Red List of Taxonomists portal at: red-list-taxonomists.eu and further disseminate the registration portal to fellow taxonomists until 31st October 2021.

Within the one-year project, the partners are to build a database of European taxonomy experts in the field of entomology and analyse the collected data to shed light on the trends in available expertise, including best or least studied insect taxa and geographic distribution of the scientists who are working on those groups. Then, they will present them to policy makers at the European Commission.

By recruiting as many as possible insect taxonomists from across Europe, the Red List of Taxonomists initiative will not only be able to identify taxa and countries, where the “extinction” of insect taxonomists has reached a critical point, but also create a robust knowledge base on taxonomic expertise across the European region to prompt further support and funding for taxonomy in the Old Continent.

On behalf of the project partners, we would like to express our immense gratitude to everyone who has self-declared as an insect taxonomist on the Red List of Taxonomists registration portal. Please feel welcome to share our call for participation with colleagues and social networks to achieve maximum engagement from everyone concerned about the future of taxonomy!

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Read more about the rationale of the Red List of Taxonomists project.

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Follow and join the conversation on Twitter using the #RedListTaxonomists hashtag. 

Development anomalies recorded for the first time in a rare tiger moth

The Menetries’ tiger moth (Arctia menetriesii) is one of the rarest and most poorly studied Palaearctic moth species. Even though its adult individuals are large and brightly coloured, they are difficult to spot, because they aren’t attracted to light, they’re not active at night, and they fly reluctantly. Currently, the species only inhabits two countries – Finland and the Russian Federation, and is included in the Red Lists of both, as Data Deficient in the former and Vulnerable in the latter.

Live male adult of Arctia menetriesii. Photo by Evgeny Koshkin

For 13 years, researcher Evgeny Koshkin of the Institute of Water and Ecology Problems of the Far Eastern branch of the Russian Academy of Sciences kept searching for the elusive Menetries’ tiger moth in its habitat in the Bureinsky Nature Reserve, 400 km north of Khabarovsk, Russia, but he only ever found it in 2018, in what was the first record of this species in 34 years in this region. That’s how rare it is.

Eggs of Arctia Menetrisii. Photo by Evgeny Koshkin

After collecting eggs from a female moth, Koshkin documented the species’ biology under laboratory conditions and described its immature stages in the open-access, peer-reviewed scientific journal Nota Lepidopterologica. For the first time, detailed photographs of all developmental stages of this species have been published. 

In laboratory conditions, the development cycle of the Menetries’ tiger moth from egg laying to an adult individual lasts between 72 and 83 days. Out of the 105 eggs that the female moth laid in captivity, however, only 13 transformed into adults, and out of those, only four were able to spread their wings. In the last larval instar, about 75% of the larvae died immediately before pupation, and a number of metamorphosis anomalies were observed in the ones that survived.

Metamorphosis anomalies in Arctia menetriesii (L-R): lethal larva-pupa intermediate; female emerged from larva-pupa intermediate – head and thorax left covered with the larval cuticle; female emerged from larva-pupa intermediate – larval cuticle removed; pupa with insignificant anomalies; pupa with severe anomalies. Photos by Evgeny Koshkin

This is the first time that such anomalies and morphological defects of pupae are documented in the Menetries’ tiger moth, and it is possible that they occur in a similar way in nature. Some metamorphosis anomalies manifested as larva-pupa intermediates due to disrupted molting, and pupae with severe anomalies produced adults that were unable to inflate their wings.

Seventh instar larva of Arctia Menetresii. Photo by Evgeny Koshkin

It is possible that the diet of the laboratory-reared larvae might have had something to do with the high mortality rate before pupation and the metamorphosis anomalies during it. Some of the larvae were fed on Aconitum leaves and larch needles during certain periods of their lives, and it is possible that toxic compounds found in these plants might have impacted their health and development. More research on larval diet would be needed, however, to confirm or reject this hypothesis.

Original source:

Koshkin ES (2021) Life history of the rare boreal tiger moth Arctia menetriesii (Eversmann, 1846) (Lepidoptera, Erebidae, Arctiinae) in the Russian Far East. Nota Lepidopterologica 44: 141-151. https://doi.org/10.3897/nl.44.62801

Carried with the wind: mass migration of Larch Budmoth to the Russian High Arctic

Live Larch Budmoth walking on tundra, Vize Island, air temperature +3C, 30.07.2020. Photo by Dr Maria Gavrilo

Arctic habitats have fascinated biologists for centuries. Their species-poor insect faunas, however, provide little reward for entomologists – scientists who study insects – to justify spending several weeks or even months in the hostile environments of tundra or polar deserts. As a result, data on insects from the High Arctic islands are often based on occasional collecting and remain scarce.

Vize Island has uniform flatland landscape with lichen-moss vegetation typicalfor High-Arctic islands. Photo by Dr Maria Gavrilo

Vize Island, located in the northern part of the Kara Sea, is one of the least studied islands of the Russian High Arctic in terms of its biota. Scientists Dr Maria V. Gavrilo of the Arctic and Antarctic Research Institute in Russia and Dr Igor I. Chupin of the Institute of Systematics and Ecology of Animals in Russia visited this ice-free lowland island in the summer of 2020. 

“Our expedition studied the ecology of Ivory Gull”, Maria Gavrilo says, “but we also looked for other wildlife.” Because of the lack of data, scientists appreciate any observation on insects they can get from the High Arctic.

On the island, the team found hundreds of small moths. They were identified by Dr Mikhail V. Kozlov of the University of Turku, Finland, as Larch Budmoths – the first and only terrestrial invertebrate to ever be observed and collected on Vize Island. Their observations are published in the open-access, peer-reviewed journal Nota Lepidopterologica.

Live Larch Budmoth walking on tundra, Vize Island, air temperature +3C, 30.07.2020. The scientists believe that this moth arrived on the island two weeks earlier after travelling with the winds some 1200 km across the Arctic ocean. Photo by Dr Maria Gavrilo 

The scientists first observed live and freshly dead moths on the sandy banks of a pond near the meteorological station. Then, they saw hundreds of them at the sandy bottom of a river valley with shallow streams. Moths, single or in groups, were mostly found at the water’s edge, along with some fine floating debris. Despite extremely low daily temperatures (+2-5°C), flying moths were also spotted on several occasions.

On average, four dead moths per 10 square meters were counted along the sandy river bed during a survey on 19.07.2020. Photo by Dr Maria Gavrilo 

The larvae of Larch Budmoth feed on the needles of different coniferous trees. Because Vize Island is located 1000 km north of the tree limit, the scientists can be sure about the migratory origin of the moths observed on Vize Island. They were likely transported there on 12–14 July 2020 by strong winds coming from the continent. The nearest potential source population of Larch Budmoth is located in the northern part of the Krasnoyarsk Region, which means they travelled at least 1200 km.

“The Arctic islands will be colonised by forest insects as soon as changing environmental conditions allow the establishment of local populations.”

Dr Mikhail V. Kozlov, University of Turku

Importantly, some moths remained alive and active for at least 20 days after their arrival, which means that long-distance travel did not critically deplete resources stored in their bodies. The current changes in climate are making it easier for more southerly insects to invade species-poor areas in the High Arctic islands – provided they can reach them and survive there.

“The successful arrival of a large number of live moths from continental Siberian forests to Vize Island has once more demonstrated the absence of insurmountable barriers to initial colonisation of High Arctic islands by forest insects”, concludes Mikhail Kozlov, who has studied Arctic insects for decades. “The Arctic islands will be colonised by forest insects as soon as changing environmental conditions allow the establishment of local populations.”

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Original source:

Gavrilo MV, Chupin II, Kozlov MV (2021) Carried with the wind: mass occurrence of Zeiraphera griseana (Hübner, 1799) (Lepidoptera, Tortricidae) on Vize Island (Russian High Arctic). Nota Lepidopterologica 44: 91–97. https://doi.org/10.3897/nl.44.63662

Double trouble: Invasive insect species overlooked as a result of a shared name

An invasive leaf-mining moth, feeding on cornelian cherry, has been gradually expanding its distributional range from its native Central Europe northwards for a period likely longer than 60 years. During that period, it has remained under the cover of a taxonomic confusion, while going by a name shared with another species that feeds on common dogwood.

To reproduce, this group of leaf-mining moths lay their eggs in specific plants, where the larvae make tunnels or ‘mines’, in the leaves. At the end of these burrows, they bite off an oval section, in which they can later pupate. These cutouts are also termed ‘shields’, prompting the common name of the family, the shield-bearer moths.

During a routine study into the DNA of leaf-mining moths, Erik van Nieukerken, researcher at Naturalis Biodiversity Center, Leiden, the Netherlands, discovered that the DNA barcodes of the species feeding on common dogwood and cornelian cherry were in fact so different that they could only arise from two separate species. As a result, Erik teamed up with several other scientists and amateur entomologists to initiate a more in-depth taxonomic study.

Curiously, it turned out that the two species had been first identified on their own as early as in 1899, before being described in detail by a Polish scientist in the 50s. Ironically, it was another Polish study, published in the 70s, that regarded the evidence listed in that description as insufficient and synonymised the two leaf-miners under a common name (Antispila treitschkiella).

Now, as a result of the recent study undertaken by van Nieukerken and his collaborators, the two moth species – Antispila treitschkiella and Antispila petryi – have their diagnostic features listed in a research article published in the open access journal Nota Lepidopterologica.

“We now establish that the species feeding on common dogwood, A. petryi, does not differ only in its DNA barcode, but also in characters of the larva, genitalia and life history,” explains Erik van Nieukerken. “A. petryi has a single annual generation, with larvae found from August to November, whereas A. treitschkiella, which feeds on cornelian cherry, has two generations, with larvae occurring in June-July and once again between September and November.”

While van Nieukerken and his team were working on the taxonomy of the moths, David C. Lees of the Natural History Museum, London, spotted a female leaf-miner in the Wildlife Garden of the museum. Following consultation with van Nieukerken, it turned out that the specimen in question was the first genuine A. treitschkiella ever to be found in Britain. Subsequently, the research groups decided to join forces, leading to the present discovery.

Despite the lack of data for the British Isles, it is already known that, in continental Europe, the cornelian cherry-feeding species had established in the Netherlands and much of Germany in the 1990s.

0.6 x 1.0

With common dogwood being widely planted, it is now suspected that A. petryi has recently reached Sweden and Estonia, even though there was no previous evidence of the leaf-miner expanding its range.

“This discovery should provoke the attention of gardeners and other members of the public alike to the invasive leafminers attacking some of our much admired trees and shrubs, as we have demonstrated for the cornelian cherry – a species well-known for its showy red berries in the autumn,” says David Lees.

“Especially in Britain, we hope that they check their photos for the conspicuous leaf mines, recognisable by those oval cutouts, to see if they can solve the mystery of when the invasion, which is now prominent on cornels around London, actually started, and how fast it progresses. Citizen scientists can help.”

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Original source:

van Nieukerken EJ, Lees DC, Doorenweerd C, Koster S(JC), Bryner R, Schreurs A, Timmermans MJTN, Sattler K (2018) Two European Cornus L. feeding leafmining moths, Antispila petryi Martini, 1899, sp. rev. and A. treitschkiella (Fischer von Röslerstamm, 1843) (Lepidoptera, Heliozelidae): an unjustified synonymy and overlooked range expansion. Nota Lepidopterologica 41(1): 39-86. https://doi.org/10.3897/nl.41.22264

Portuguese moth’s mystery solved after 22 years

An unknown moth, collected from Portugal 22 years ago, has finally been named and placed in the tree of life thanks to the efforts of an international team of scientists. The moth was unambiguously placed in the family of geometer moths (Geometridae), commonly known as loopers or inchworms due to the characteristic looping gait of their larvae.

The new species description is published in the open access journal Nota Lepidopterologica, along with a taxonomic review of the genus Ekboarmia, thought to comprise four species in the western Mediterranean area.

The first specimen, a male, was found in 1995 in Lagoa de Santo André, south of Lisbon, near the Atlantic coast. Despite its unique appearance, the specialists did not find enough similarities with any other European species, making its classification impossible. When three females were finally found following an intensive search in 2009, the team of scientists hoped they would find enough evidence to solve the mystery.

“The discovered females had different wing patterns compared to the males, suggesting sexual dimorphism, adding another complexity in the identification. This new species could not have been classified on the basis of external characters alone,” explains Dieter Stüning from Zoologisches Forschungsmuseum Alexander Koenig, Bonn, Germany.

In 2015, two specimens, a male and a female, have been DNA barcoded and recently became targets of detailed morphological examinations. DNA data played an essential role in demonstrating that the male and the female belong to the same species, whereas morphological structures finally provided unambiguous evidence to place the mystery moth in the geometrid genus Ekboarmia. The species name miniaria seemed appropriate to denote its small size. The tiny moth is the smallest in its genus whose other species are externally dissimilar.

Peder Skou from Denmark played a central role in the discovery of the species, tirelessly searching for more material to solve the questions. “Discovery of an undescribed and distinct macromoth from Europe is a rare occasion, because the continent’s fauna is probably the most exhaustively studied in the world,” explains Skou.

Pasi Sihvonen from the Finnish Museum of Natural History concludes: “Virtually nothing is known about the species. Altogether, only 11 specimens have been found between 1995 and 2011. Larvae of related species feed on juniper needles, which might also be the foodplant of the new species. We hope that the richly illustrated publication of the new moth will lead to new discoveries of this mysterious species. More data are needed, for instance, its conservation status cannot be evaluated due to insufficient life history and distribution data.”

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Original source:

Skou P, Stüning D, Sihvonen P (2017) Revision of the West-Mediterranean geometrid genus Ekboarmia, with description of a new species from Portugal (Lepidoptera, Geometridae, Ennominae). Nota Lepidopterologica 40(1): 39-63. https://doi.org/10.3897/nl.40.10440

New moth in Europe: A southern hemisphere species now resident in Portugal

As travelling in the 21st century is easier than ever, so is for species to make their way to new areas, sometimes increasing their distributional range, or even establishing whole new habitats. On the other hand, when they leave their natural predators and competitors behind, and find abundance of suitable resources somewhere else, they are running the risk of becoming invasive.

Nevertheless, such is not the case of a small, darkish brown moth from the southern hemisphere that is now resident in central Portugal. There, the species do not exhibit invasive behaviour, and so far has been only observed in very low numbers. The discovery is published in the open access journal Nota Lepidopterologica by an international research team, led by Martin Corley, CIBIO-InBIO, Portugal.

In 2012, Jorge Rosete, one of the co-authors of the study, spotted a female specimen that he could not identify near his house. When Martin took a look at it, he placed it in the concealer moth family (Oecophoridae), but was unable to recognise neither its species, nor its genus. It did not took long before a few more specimens were found, including males.

Initially, Martin thought the moth might originate from Australia, given the abundance of eucalyptus plantations in the area where it was found, and the fact that there are more concealer moth species in Australia than on any other continent. However, despite their efforts and contacts with other researchers, they failed to find an Australian species to match the Portuguese specimens. As a result, the mystery remained for the next four years, until a molecular study into moth DNA pulled the curtains.

A fragment of DNA, also called DNA barcode, matched three other genetically identical unnamed specimens, originally collected from South Africa, in the DNA database BOLD. Further collaboration with Alexander Lvovsky, Russian Academy of Sciences, allowed the assignation of the specimens to a species name: Borkhausenia intumescens, known from South Africa. However, it did not end there. Further research into museum collections showed that in fact this species had been previously described from Argentina as Borkhausenia crimnodes, and therefore should be named as such.

The origin of the Portuguese specimens remain a mystery, but it is evident that the species is now established in central Portugal. The larvae of other species in the same genus feed on decomposed plants, so this is likely the case with the moth species as well. It might be that it has entered the country through Figueira da Foz port along with imported timber from South America intended for the paper industry.

It is not known if this is a South African species that had first been transported to South America, and then – to Portugal, or if it is originally South American. It is also possible that it is not native in neither of these areas, and instead originates from another country, where it has not even been discovered yet. The moth favours warm temperate zones and potentially might appear anywhere in the world with suitable climate.

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Original source:

Corley MFV, Ferreira S, Lvovsky AL, Rosete J (2017) Borkhausenia crimnodes Meyrick, 1912 (Lepidoptera, Oecophoridae), a southern hemisphere species resident in Portugal. Nota Lepidopterologica 40(1): 15-24. https://doi.org/10.3897/nl.40.10938.