Category: Nota Lepidopterologica

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.

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.