Invasive fruit fly may pose threat to forest ecosystems

The decay of fruits attacked by the spotted wing drosophila leads to a loss of resources, which can cause considerable ecological damage.

The invasive spotted wing drosophila (SWD), introduced from South-East Asia, is a well-known fruit crop pest. It lays its eggs by destroying the mechanical protection of the fruit’s skin, providing an entry point for further infestation. Egg deposition and inoculated microbes then accelerate decay, and as a result the fruit rots and becomes inedible. While this small fly is known to cause massive economic damage in agriculture, little is known about its ecological impact on more natural ecosystems such as forests.

The larvae of the invasive spotted wing drosophila develops in fruits of many forest species such as brambles. Its occurrence result in a fast decay of the fruits.

A recent study by Swiss scientists from the Swiss Federal Institute for Forest, Snow and Landscape Research WSL and the Ökobüro Biotopia, published in the scientific journal NeoBiota, concluded that the SWD competes strongly with other fruit-eating species and that its presence could have far-reaching consequences for ecosystems.

The research team assessed the use of potential host plants at 64 sites in forests from mid-June to mid-October 2020 by checking a total of 12,000 fruits for SWD egg deposits. To determine if SWD attacks trigger fruit decay, they also recorded symptoms of fruit decay after egg deposition. In addition, they monitored the fruit fly (drosophilid) fauna in the area, assuming that the SWD would outnumber and possibly outcompete other fruit-eating insects.

The male of the invasive spotted wing drosophila can be easily identified by the dark spots on the wings.

The authors found egg deposits on the fruits of 31 of the 39 fruit-bearing forest plant species they studied, with 18 species showing an attack rate of more than 50%. Furthermore, more than 50% of the affected plant species showed severe symptoms of decay after egg deposition. The egg depositions may alter the attractiveness of fruits, because they change their chemical composition and visual cues, such as colour, shape and reflective patterns, which in turn might lead seed dispersers such as birds to consume less fruits.

Given the large number of infested fruits, significant ecological impacts can be expected. “Rapid decay of fruits attacked by the spotted wing drosophila results in a loss of fruit available for other species competing for this resource, and may disrupt seed-dispersal mutualisms due to reduced consumption of fruit by dispersers such as birds,” says Prof. Martin M. Gossner, entomologist at the WSL. “If the fly reproduces in large numbers, both seed dispersers and plants could suffer.”

The females of the invasive spotted wing drosophila has an enlarged, serrated ovipositor to attack undamaged fruits, which gives it a competitive advantage over native fruit flies.

The authors further found that SWD were strongly represented and dominant in trap catches, and showed that the more abundant SWD were, the less abundant native drosophilids were. This suggests additional negative impacts of the invasive species on native communities.

With ongoing climate change, these potentially severe ecological impacts might be amplified in temperate forests, as higher average and winter temperatures will most likely lead to shorter generation times and lower winter mortality, which will eventually further increase the pressure on forest fruits and the competitiveness of the SWD over native drosophilids, the authors note.

Research article:
Bühlmann I, Gossner MM (2022) Invasive Drosophila suzukii outnumbers native controphics and causes substantial damage to fruits of forest plants. NeoBiota 77: 39-77. https://doi.org/10.3897/neobiota.77.87319

Photos by Prof. Martin M. Gossner.

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Study ranks potentially harmful invasive species in Ghana

Scientists ranked the 110 arthropod and 64 pathogenic species posing the greatest potential threat to the country if established.

A CABI-led study has conducted a comprehensive survey of nearly 200 potentially harmful alien plant species that could have a detrimental impact upon agriculture, forestry and biodiversity in Ghana once they enter the country.

Invasive Alien Species (IAS) continue to shape the global landscape through their effects on biological diversity and agricultural productivity. The effects are particularly pronounced in Sub-Saharan Africa, which has seen the arrival of many IAS in recent years. This has been attributed to porous borders, weak cross border biosecurity, and inadequate capacity to limit or stop invasions.

A farmer shows cassava root affected by cassava brown streak virus alongside a healthy root in a country where the disease is present – one of the 64 pathogens assessed by the scientists. Credit: CABI

The research, the findings of which are published in the journal NeoBiota, ranks 110 arthropod and 64 pathogenic species that pose the greatest threat but are not yet officially present in the country. However, they could arrive as ‘stowaways’ in cargo from other countries around the world, the scientists believe.

Dr Marc Kenis, Head Risk Analysis and Invasion Ecology at CABI, led on the horizon scanning exercise supported by colleagues from a range of institutions including Ghana’s Plant Protection and Regulatory Services Directorate (PPRSD).

Among the top arthropods prioritised by Dr Kenis and his team were the pink hibiscus mealybug (Maconellicoccus hirsutus Green) and melon thrips (Thrips palmi Karny) while the top pathogens highlighted include cassava brown streak virus and Maize lethal necrosis disease.

Cassava in Ghana, for example, is a main staple crop and contributes about 22% and 30% to the Agricultural Gross Domestic Product (AGDP) and daily calories intake respectively. The crop, however, can be at risk from cassava brown streak virus which can reduce yields by up to 70%.

Maize lethal necrosis disease, on the other hand for instance, can be a major disruptor of maize crops in Ghana where maize accounts for more than 50% of the country’s total cereal production. The disease can cause losses of between 50-90% depending on the variety of maize and the growing conditions of the year.

The scientists also found other species recorded in Africa that included 19 arthropod and 46 pathogenic species which were already recorded in the neighbouring countries of Burkina Faso, Côte d’Ivoire, and Togo.

Dr Kenis, who is based at CABI’s centre in Switzerland, said, “The ultimate objective of this research was to enable prioritization of actions including pest risk analysis, prevention, surveillance and contingency plans. Prioritisation was carried out using an adapted version of horizon scanning and consensus methods developed for ranking IAS worldwide.

“We have demonstrated that through horizon scanning, a country can identify potential invasive plant pests, both invertebrates and pathogens, and use the information to determine the risk associated with each.

“This will enable the country to invest the limited resources in priority actions such as preventing arrival and establishment of IAS, Pest Risk Analysis (PRA), surveillance and developing contingency plans.

“This study can serve as a model for future projects on plant pests’ prioritisation in Africa and elsewhere. It would be applicable for assessing the risk of invasive plant pests in any country or region, e.g. trade blocks, with minor modifications of the method, particularly in the mini-PRA protocol used to score species.”

The full lists of arthropod and pathogenic species surveyed can be found within the full paper which can be read online.

Mr Prudence Attipoe, Deputy Director Head Plant Quarantine Division, PPRSD, said, “The horizon scanning exercise for Ghana would give the PPRSD an insight into invasive pests which could possibly enter the Nation. The tool is timely and appropriate for conducting PRA for planning, training and future preparedness. The success of this exercise would pre-empt the introduction of these invasive pests into the country in order to protect Ghana’s agriculture, forestry and also cause staff of PPRSD to be more vigilant at the borders for these pests.”

Research paper:

Kenis M, Agboyi LK, Adu-Acheampong R, Ansong M, Arthur S, Attipoe PT, Baba A-SM, Beseh P, Clottey VA, Combey R, Dzomeku I, Eddy-Doh MA, Fening KO, Frimpong-Anin K, Hevi W, Lekete-Lawson E, Nboyine JA, Ohene-Mensah G, Oppong-Mensah B, Nuamah HSA, van der Puije G, Mulema J (2022) Horizon scanning for prioritising invasive alien species with potential to threaten agriculture and biodiversity in Ghana. NeoBiota 71: 129 148. https://doi.org/10.3897/neobiota.71.72577

Unwelcome guests: International tourism and travel can be a pathway for introducing invasive species

International tourism can facilitate the dispersal of exotic species. A new analysis of data from tourism accommodations and exotic organism detections in New Zealand, published in NeoBiota, shows that levels of detection significantly correlated to international and domestic tourist movement, even with population levels taken into account. There was no detectable difference between the risk from international and domestic tourists, indicating that tourism as an activity correlates with the introduction and spread of exotic species.

Tourists, albeit unwittingly, may help such unwanted organisms spread further and conquer new lands – they can carry them over in their luggage or on their clothes and shoes. In 2011, a study from New Zealand found that, for every gram of soil on the footwear of aircraft passengers arriving from abroad, there were 2.5 plant seeds, 41 roundworms, 0.004 insects and mites, and many microorganisms, such as fungi that could cause plant diseases. Moreover, these organisms were alive, and some of them were known to be biosecurity threats. Importantly, tourism can introduce risk in two directions, namely from the arrival of international travellers and also the return of residents from international travel.

An important question, then, is to what degree they play a role in the spread of exotic organisms. A study, carried out by Dr Andrew Robinson of the Centre of Excellence for Biosecurity Risk Analysis at the University of Melbourne and Mark McNeill of AgResearch New Zealand, looks to answer that question.

To do so, the researchers compared data on the interceptions of exotic organisms in New Zealand against accommodation data for international and domestic tourists, factoring for the country’s population distribution. The study, recently published in the open-access journal NeoBiota, covered the period between 2011 and 2017, and the exotic organisms that were detected included insects, spiders, mites, snails, plants, and roundworms. 

Robinson and McNeill found a significant relationship between levels of incursion detection and tourism accommodation records: the number of nights spent in hotels significantly correlated to the detection of exotic pests for that period. Importantly, the study found no significant difference between the effect of international and domestic tourism, proving that even travel within the country can facilitate the spread of exotic species. A significant positive correlation was also found between the detection of exotic organisms and population numbers across different regions. 

“The core take-home message is that within-country tourism movements are significantly correlated to the detection of exotic pests,” the researchers explained. That is, tourists and returning residents bring bugs in, and both are implicated at spreading them once they are in the country. They suggest that biosecurity authorities should continue allocating resources to the management of invasive species and pests that get carried around by tourists and their activities. 

However, they also point to the biosecurity risk posed by other possible pathways for of exotic organisms, such as sea freight. A comparison between the different ways of introduction and dispersal would provide a better understanding of relative risk, they conclude.

Research article:

Robinson AP, McNeill MR (2022) Biosecurity and post-arrival pathways in New Zealand: relating alien organism detections to tourism indicators. NeoBiota 71: 51-69. https://doi.org/10.3897/neobiota.71.64618

Desert locusts remain a serious threat to Pakistan

The recent Desert Locust upsurge had a major impact on Pakistan’s agriculture, with swarms causing immense damage to all types of crops. A joint French-Pakistani team provides an overview of the dynamics of this upsurge, assesses its impact and control measures, and clarifies the role of different stakeholders in the management of this pest, suggesting various improvements for the future. The study was published in the open access Journal of Orthoptera Research.

In 2019 and 2020, desert locusts once again plagued parts of East Africa and huge areas as far as India and Pakistan through the Arabian Peninsula, in an infestation that was described as the worst in decades. A serious agricultural pest, the desert locust Schistocerca gregaria can feed on most types of crops, including grains, vegetables and fruit, causing significant damage to agricultural production and threatening food security in many countries.

Since the 1960s, a preventive control strategy against this pest has been implemented, based on monitoring of outbreak areas and ecological conditions, followed, if necessary, by early intervention and limited use of pesticides, so that any outbreak can be stopped as soon as possible. With 60 years of hindsight, desert locust invasions are now less frequent, smaller in scale and, if they cannot be stopped early, they are adequately managed.

Desert Locust: mature adult. Photo by A. Monard, CIRAD

However, financial and political uncertainties in many parts of the desert locust’s range continue to sustain the threat, and not all invasions can be stopped early. This was the case in 2018, when such an upsurge was largely aided by rains in the southern Arabian Peninsula. Locusts could not be detected for several months and therefore went unchecked, mainly due to the insecure conditions, especially in Yemen. The swarms then progressively contaminated a large part of East Africa and spread to Iran, Pakistan and India. Pakistan, in particular, subject to periodic swarm invasions in the past, faced a particularly severe situation in 2019-2020, where the swarms could only be contained after several months of intensive control.

Scientists Riffat Sultana, Ahmed Ali Samejo and Samiallah Soomro (University of Sindh, Pakistan), Santosh Kumar (University of Cholistan, Pakistan) and Michel Lecoq (former director of a locust research unit at CIRAD, France) synthesised these two years of upsurge in a new research article published in the open-access Journal of Orthoptera Research. They focused on Pakistan, the damage caused in this country, and the surveillance and control operations undertaken, clarifying, at the same time, at both national and international level, the role of the different actors in the management of this pest, and suggesting some improvements for the future.

Desert Locust: hopper. Photo by A. Foucart, CIRAD

During this upsurge, a great deal of damage was caused to all types of crops. The Government of Pakistan’s preliminary estimate of monetary losses due to desert locusts for the agricultural seasons 2020 and 2021 ranges from $3.4 billion to $10.21 billion. More than 3 million people were facing severe acute food insecurity.

The authors also note that Pakistan needs to continue to be prepared and improve the prevention system already in place. They suggest developing compensatory measures for local populations in the event of an uncontrolled invasion at an early stage, increasing the use of alternatives to chemical pesticides such as mycopesticides, and maintaining funding mechanisms that provide sustainable support even in times of recession. Perhaps the most important challenge is certainly to maintain long-term efforts to build resilience, despite the apparent absence of imminent threats.

Research article:

Sultana R, Kumar S, Samejo AA, Soomro S, Lecoq M (2021) The 2019–2020 upsurge of the desert locust and its impact in Pakistan. Journal of Orthoptera Research 30(2): 145-154. https://doi.org/10.3897/jor.30.65971

New methods needed to boost success of Classical Biological Control to fight insect pests

The success of Classical Biological Control in the Western Paleartic ecozone is rarely dependent on the released biological control agent, but more often on other factors, such as the target pest, its host plant, or the circumstances of the releases

A CABI-led study has revealed that the success of Classical Biological Control (CBC) in Europe, North Africa and the Middle East is only rarely dependent on the released biological control agent, but more often on other factors, such as the target pest, its host plant, or the circumstances of the releases.

The research – published in the journal NeoBiota – suggests that the overall success of biological control introductions of insect predators and parasitoids against herbivorous insects in the Western Paleartic ecozone is comparable to the success of CBC worldwide. However, over 100 years of CBC in this region, has resulted in no overall rise in success in the fight against insect pests – including those of crops such as citrus, olive, potato, mulberry and various other fruits.

An illustration of a case of biological control of the Comstock mealybug Pseudococcus comstocki with the parasitoid wasp Allotropa burrelli. Image by Lukas Seehausen

Lead author Dr Lukas Seehausen, together with colleagues from CABI Switzerland, the University of Lisbon and the University of Bordeaux, argue that a focus on life-history traits of the biological control agent to increase the chances of successful CBC is not fully justified and should be complemented with the consideration of traits regarding the pest and its host plant, as well as other aspects of CBC, such as climate and management – including ways in which CBC agents are released.

For example, if a CBC agent is released repeatedly against the same pest in different years and countries, the chances of successful establishment and control of the target increase. This is an indication for the importance of release strategies for the success of CBC programmes.

Dr Seehausen said, “What makes our study different from others is that we studied factors that may impact the outcome of CBC not independently of each other but using a holistic analysis, which reveals their relative importance within the complexity of CBC programmes.

“The results from this study should be understood as a first step to give the incentive for a holistic, rather than an independent consideration of factors affecting the success of CBC.”

By filtering data from the BIOCAT catalogue, the scientists found that 780 introductions of insects for biological control were undertaken in the Greater Western Palearctic ecozone between 1890 and 2010. This constituted 416 agent-target combinations.

The results showed that eight countries were responsible for more than two thirds (70.5%) of all introductions: Israel (16.3%), Italy (14.0%), Former USSR (10.1%), France (7.3%), Greece (7.1%), Spain (6.0%), Egypt (5.3%), and Cyprus (4.4%). Within these countries, the percentage of complete target control was very variable.

Overall, the study showed that while the success of agent establishment was 32%, the successful impact of single agents on their target was 18% and the success of complete control was 11%.

However, the success rates of agent establishment and target control were higher in CBC projects targeting pests of woody plants than pests of other types of plants.

A reason for this, the scientists say, might be that being perennial, trees provide a more stable and predictable environment when compared to herbaceous plants such as annual plants or crops.

In carrying out the research, Dr Seehausen and the team added 15 new explanatory variables including consideration of the biological control agent feeding strategy, host range and life-stage killed by the biological control agent.

Dr Seehausen explains, “We found that only a few CBC agent-related factors significantly influenced the success of CBC – suggesting that the reoccurring focus on agent-related traits is not justified.

“Our attention should be redirected to include lower trophic levels and other aspects of CBC – such as abiotic factors including climate and management.”

The scientists conclude by stressing that analysis of the entire BIOCAT catalogue, or an updated version including more factors, should lead to further insights and help to develop decision support tools to increase the success of CBC at all levels.

Original source:

Seehausen ML, Afonso C, Jactel H, Kenis M (2021) Classical biological control against insect pests in Europe, North Africa, and the Middle East: What influences its success? NeoBiota 65: 169-191. https://doi.org/10.3897/neobiota.65.66276

New improvements to how impacts of non-native species are assessed recommended

A farmer sets a pheromone trap to fight tomato leaf miner. Photo by CABI.

The Centre for Agriculture and Bioscience International (CABI) has led an international team of non-native species (NNS) specialists who have compiled a list of recommendations to improve the way in which the impact of a range of invasive pests – such as the tomato leaf miner Tuta absoluta – are assessed, potentially helping towards ensuring greater global food security.

Lead authors Dr Pablo González-Moreno and Dr Marc Kenis, Senior Researchers at CABI are two of 89 NNS experts from around the world who have collaborated on the paper, published in NeoBiota, that calls for ‘more robust and user-friendly’ impact assessment protocols to predict the impacts of new or likely invaders as well as to assess the actual impact of established species.

The manuscript is the outcome of an enormous collective effort using 11 different protocols to assess the potential impact of 57 NNS to Europe yielding a total of 2614 separate assessments. This unique dataset has allowed the authors to identify which are the main factors increasing the robustness of protocols and provide recommendations on how the robustness and applicability of protocols could be enhanced for assessing NNS impacts.

As reported in the study, entitled ‘Consistency of impact assessment protocols for Non-Native Species’, Dr González-Moreno and fellow scientists – from 80 institutions including the UK-based Centre for Ecology & Hydrology (CEH), University of Milan, University of Bern and Queens University Belfast – argue that ‘assessment of the realised or potential impacts of NNS is particularly important for the prioritization of management actions.’

Millions of the world’s most vulnerable people face problems with invasive weeds, insects and plant diseases, which are out of control and have a major impact on global prosperity, communities and the environment. Developing countries are disproportionately affected.

The global cost of the world’s 1.2 million invasive species is estimated at $1.4 trillion per year – close to 5 percent of global gross domestic product. In East Africa, five major invasive species alone cause $1 billion in economic losses to smallholder farmers each year.

The scientists believe that, currently, the large variety of metrics adopted to measure the impacts of invasive species undermines direct comparison of impacts across species, groups of taxa, localities or regions. They go on to argue that in general we have ‘little understanding of the patterns in consistency of impact scores across assessors and protocols, and more importantly, which factors contribute to high levels of consistency.’

Dr González-Moreno said,

“There is an increasing demand for robust and user-friendly impact assessment protocols to be used by professionals with different levels of expertise and knowledge.
Robust NNS impact protocols should ideally result in accurate and consistent impact scores for a species even if applied by different assessors, as long as they have the adequate expertise in the assessed species and context.
Several key factors should be taken into account when selecting or designing an NNS risk assessment protocol, such as the aim, the scope, the consistency and the accuracy of the outcomes, and the resources available to perform the assessment – for example time or information available.”

In compiling a list of recommendations for improved NNS impact protocols, Dr González-Moreno and the team of researchers used 11 different protocols to assess the potential impact of 57 species not native to Europe and belonging to a very large array of taxonomic groups (plants, animals, pathogens) from terrestrial to freshwater and marine environments.

They agree that using a ‘5-level scoring, maximum aggregation method and the moderation of expertise requirements’ offers a good compromise to reducing inconsistencies in research findings without losing discriminatory power or usability.

Dr González-Moreno added, “In general, we also advise protocol developers to perform sensibility tests of consistency before final release or adoption. This is crucial as if a protocol yields inconsistent outcomes when used by different assessors, then it is likely that decisions taken based on the results could be variable and disproportionate to the actual impacts.”

Original source:

González-Moreno P, Lazzaro L, Vilà M, Preda C, Adriaens T, Bacher S, Brundu G, Copp GH, Essl F, García-Berthou E, Katsanevakis S, Moen TL, Lucy FE, Nentwig W, Roy HE, Srėbalienė G, Talgø V, Vanderhoeven S, Andjelković A, Arbačiauskas K, Auger-Rozenberg M-A, Bae M-J, Bariche M, Boets P, Boieiro M, Borges PA, Canning-Clode J, Cardigos F, Chartosia N, Cottier-Cook EJ, Crocetta F, D’hondt B, Foggi B, Follak S, Gallardo B, Gammelmo Ø, Giakoumi S, Giuliani C, Guillaume F, Jelaska LS, Jeschke JM, Jover M, Juárez-Escario A, Kalogirou S, Kočić A, Kytinou E, Laverty C, Lozano V, Maceda-Veiga A, Marchante E, Marchante H, Martinou AF, Meyer S, Michin D, Montero-Castaño A, Morais MC, Morales-Rodriguez C, Muhthassim N, Nagy ZA, Ogris N, Onen H, Pergl J, Puntila R, Rabitsch W, Ramburn TT, Rego C, Reichenbach F, Romeralo C, Saul W-C, Schrader G, Sheehan R, Simonović P, Skolka M, Soares AO, Sundheim L, Tarkan AS, Tomov R, Tricarico E, Tsiamis K, Uludağ A, van Valkenburg J, Verreycken H, Vettraino AM, Vilar L, Wiig Ø, Witzell J, Zanetta A, Kenis M (2019) Consistency of impact assessment protocols for non-native species. NeoBiota 44: 1-25. https://doi.org/10.3897/neobiota.44.31650

Additional information:

The paper is based upon work from the COST Action TD1209: ALIEN Challenge. COST (European Cooperation in Science and Technology) is a pan-European intergovernmental framework. The mission of COST is to enable scientific and technological developments leading to new concepts and products and thereby contribute to strengthening Europe’s research and innovation capacities.

Dr Pablo González-Moreno was supported by the CABI Development Fund (with contributions from ACIAR (Australia) and DFID (UK) and by Darwin plus, DPLUS074 ‘Improving biosecurity in the SAUKOTs through Pest Risk Assessments’.

 

Text originally published by CABI.

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

It’s a girl! Tweaking the names of a pest fanworm group

The largest group of fanworm species with rigid chalky (calcareous) tubes belong to the Hydroides genus, and are easily recognised thanks to the shape of their beautifully ornate tube plugs. Hydroides is economically important as its members have the potential to cover immersed marine structures with massive nuisance settlements of chalky biofouling. The best-known example is Hydroides elegans, which settles on boat hulls so readily that colonies of it are perpetually in transit around the world, hitch-hiking to new places.

Latin names of animals mostly do not change over the decades because they are kept stable by a code book of naming rules. However, a mistake has recently been discovered regarding Hydroides. It turns out that it is a feminine genus rather than masculine, thus requiring each of the 107 Hydroides species names, described since 1768, to be re-examined so that the appropriate spelling, determined by the derivation of each name, can be used consistently by all biologists in future.

Scientists Geoffrey Read, National Institute of Water and Atmospheric Research, New Zealand, Harry ten Hove, Naturalis Biodiversity Center, the Netherlands, Yanan Sun and Elena Kupriyanova, Australian Museum, have carefully compiled the data on original Hydroides names, and published a checklist paper in the open access journal ZooKeys.

‘Detective’ work has often been required to get the details, as early biologists have been remarkably vague about the names they created and where their worms had come from. Fortunately, the Biodiversity Heritage Library has digitised many of the legacy taxonomic works required and it was possible to find out some unexpected information such as that species H. floridana actually did not come from Florida, although its name suggests it did.

three_hydroidesminaxSome Hydroides names have a descriptive basis that fits how the worms look, such as H. bulbosa, H. elegantula and H. longispinosa, others are named after people or places, for example, H. dafnii (after its collector, Yaacob Dafni) and H. sanctaecrucis (after Saint Croix Island). Yet, there are others, whose names are of quite tricky origin. It turns out that H. dianthus was actually named after a group of popular garden flowers, and H. euplaeana and H. stoichadon commemorate the long-forgotten names of tiny Mediterranean islands.

A few 19th century Hydroides descriptions are so bad that taxonomists have given up on using the names. However, one of these discarded names was revived last century by American biologists and was then used in often-cited research on sperm biology. Now, we can only guess what the actual species was.

Hydroides itself is a very old name, but it arose in a somewhat accidental and misleading way (in a letter to Linnaeus), because the worms have absolutely no connection to true hydroids, the well-known group of colonial animals related to corals.

The Hydroides species original descriptions are mostly accessible via the checklist because one third of the reports cited in the checklist are linked to the open access Biodiversity Heritage Library, and a large proportion are matched to an online source. While in the past one could only expect to find recorded the geolocations (the latitudes and longitudes) of worms collected during ship voyages, now the original localities of all the Hydroides are finally mapped. Further information on the taxonomy of all Hydroides, including many now regarded as synonyms, is available via links to the World Register of Marine Species Polychaeta web pages.

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Original source:

Read GB, ten Hove HA, Yanan Sun Y, Kupriyanova EK (2017) Hydroides Gunnerus, 1768 (Annelida, Serpulidae) is feminine: a nomenclatural checklist of updated names. ZooKeys 642: 1-52. https://doi.org/10.3897/zookeys.642.10443