Status of invasive alien plants included in EPPO Lists in Turkey

Turkey is one of the richest areas in the middle latitudes in terms of plant diversity. It has approximately 12 000 plant species and a great number of new species are being added each year. However, invasive alien species have not yet been fully considered in Turkey and only two plant species are in Turkey's quarantine list (Arceuthobium spp. and Eichhornia crassipes). EPPO is an intergovernmental organization responsible for cooperation in plant protection in the European and Mediterranean region and maintains the A1 and A2 Lists of pests recommended for regulation (A1 species are absent from the EPPO region, A2 species are present but of limited distribution), the List of Invasive Alien Plants, the Observation List of invasive alien plants and the Alert List. Eichhornia crassipes, Heracleum persicum, Heracleum sosnowskyi, Ludwigia peploides, Polygonum perfoliatum and Solanum elaeagnifolium are among the species which were recorded in Turkey and are included in the EPPO A2 List. Species recorded in the EPPO List of invasive alien plants which are present in Turkey are: Acroptilon repens, Ailanthus altissima, Ambrosia artemisiifolia (= A. elatior), Carpobrotus edulis, Cortaderia selloana, Cyperus esculentus, Paspalum distichum (= P. paspalodes), Oxalis pes‐caprae and Sicyos angulatus. Azolla filiculoides and Rhododendron ponticum are listed in the EPPO Observation List of Invasive alien plants and Miscanthus sinensis, listed in the EPPO Alert List, are also recorded in the Turkish flora.     

Review of the current situation for Solanum elaeagnifolium in the Mediterranean Basin

Silverleaf nightshade (Solanum elaeagnifolium, Cav.) is one of the important invasive plant species in Mediterranean Basin countries. Over the last 60 years, this plant has gone from a few accidental introductions to near monospecific populations in many areas of the Mediterranean Basin (in particular Greece and Morocco). Recent findings from Lebanon show that the invasion is ongoing. Solanum elaeagnifolium has a negative impact on crops, causing up to 75% yield loss, as well as an indirect impact by harbouring plant pests and diseases. Solanum elaeagnifolium is toxic to livestock and has a negative affect on the quality of life for humans. Losses of potential resource or revenue caused by its invasion include: decreased forage quality on grazing lands; decreased cropping land and amenity values of public space; increased water loss; increased water conveyancing costs; and increased forest restoration costs. Available control techniques need to be strengthened to reduce the impact of S. elaeagnifolium and prevent its spread. More attention needs to be devoted to biological control, which could provide regional management of this invasive alien plant. Sustainable management of S. elaeagnifolium will require coordination, education and support across the affected countries. Governments must have the means to detect, manage and control S. elaeagnifolium.     

Genetic variation and structure of Solanum elaeagnifolium in Australia analysed by amplified fragment length polymorphism markers

Solanum elaeagnifolium is a weed of national significance in Australia. However, the genetic diversity of S. elaeagnifolium is poorly understood. Four amplified fragment length polymorphism primer combinations were utilised to investigate the genetic variation and structure of 187 S. elaeagnifolium individuals collected from 94 locations in Australia. High genetic diversity was found, with an average Jaccard's genetic similarity at 0.26. Individuals were assigned to two genetic clusters or considered as admixed according to their membership coefficient value (q) calculated by Bayesian model‐based genetic structure analysis. This suggested that Australian S. elaeagnifolium may have originated from two distinct gene pools. These results were further supported by principal co‐ordinates analysis. Large spatial groups of individuals assigning to these two gene pools were found in western Victoria and south‐western New South Wales (NSW) and northern NSW, which correlated well with the early records of S. elaeagnifolium in both regions. The high genetic diversity found here could add difficulties to effective control of S. elaeagnifolium across regions.     

First report of Thrips setosus in Belgium

The Japanese flower thrips, Thrips setosus, is a polyphagous insect which in Europe has mainly been observed on hydrangeas (Hydrangea spp.). The first report of T. setosus in the EPPO region was in the Netherlands (2014). Since then it has been observed in four other countries inside the EPPO region: Germany (2015), the United Kingdom (2016), France (2016) and Croatia (2016). Its dispersal is most likely to be related to trade. Because of its polyphagous nature, there is a risk of spread to other economically important crops. Therefore, T. setosus was included in the national survey project ‘STATREGO’, during which the status of several invasive plant pests and diseases in Belgium was determined.     

Preventing a new invasive alien plant from entering and spreading in the Euro‐Mediterranean region: the case study of Parthenium hysterophorus

Parthenium or famine weed (Parthenium hysterophorus L.) is an annual plant originating from the Americas, which is a major invasive alien plant in almost all continents. While the deleterious impacts of the species on agriculture, human and animal health have been well documented, information on the pathways of entry of the species is only occasionally mentioned in the literature. As this invasive alien plant is only recorded as established in Israel and Egypt within the Euro‐Mediterranean region, the European and Mediterranean Plant Protection Organization identified P. hysterophorus as an emerging threat. EPPO therefore performed a Pest Risk Analysis on this species to assess the risk it represents and to consider appropriate management options. The EPPO Pest Risk Analysis main outputs are summarized in this article, indicating the probability of entry of the species via the different pathways within the EPPO region, its probabilities of establishment and spread, and the magnitude of its potential agricultural, environmental and social impacts.     

Eradication and control of invasive alien plants in the Mediterranean Basin: towards better coordination to enhance existing initiatives

The European and Mediterranean Plant Protection Organization (EPPO), in the framework of its activities in the Mediterranean Basin, launched a questionnaire to gather information on eradication actions and control actions for invasive alien plants. Thirty‐four (34) eradication actions were reported, 16 occurring in Spain, 7 in Italy, 7 in France, 1 in Portugal, 1 in Malta, and 2 on the southern rim of the Mediterranean, with 1 in Israel and 1 in Tunisia. Twenty‐two (22) species were targeted, and the habitats where such actions were undertaken most frequently were coastal dunes, sandy shores and aquatic ecosystems. Most of the species that have been the object of an eradication action were known invasive species recorded in the EPPO lists, such as Ailanthus altissima, Buddleia davidii, Carpobrotus spp., Eichhornia crassipes, Ludwigia peploides, Pennisetum setaceum, Pistia stratiotes, Solanum elaeagnifolium and Sicyos angulatus. Other eradicated species have a limited distribution in the EPPO region and may represent emerging invasive plants, such as Ambrosia confertifolia, Cylindropuntia rosea, Leersia oryzoides, Leptochloa fusca subsp. uninervia and Marsilea drummondii. Control actions concerning 90 species were also reported. A large number of eradication actions, as well as management actions, are therefore happening in Mediterranean countries. At present countries appear to operate with complete autonomy, without consulting neighbouring countries or other stakeholders within the country. There is therefore a need for coordination of new eradication actions.     

Solanum elaeagnifolium,a potential source of Potato virus Y (PVY) propagation*

In the context of an epidemiological study on Potato virus Y (PVY) in potato crops, Solanum elaeagnifolium Cav. was included in the weeds prospected. Surveys were carried out in four seed potato areas: Cap Bon, Manouba, Jendouba and Kairouan. S. elaeagnifolium was found in all areas, except Cap Bon. Virus‐like symptoms were observed on some S. elaeagnifolium plants in the field, i.e. leaf mottling and curling. Aphids were collected on these plants and were identified as Myzus persicae and Aphis fabae, both known to colonize potatoes and to transmit the standard PVY^N isolate with transmission efficiencies of 95% and 43%, respectively. Forty‐seven plant samples were tested with ELISA for the presence of PVY. Positive reactions were obtained from 2/6, 5/18, 8/23 samples collected in Manouba, Jendouba and Kairouan, respectively. Virus transmission was carried out using M. persicae as vector from two samples of each region onto plantlets of Nicotiana tabacum cv Xanthi. All inoculated plantlets displayed typical symptoms of the PVY^N strain group, confirmed by serological testing using specific antibodies. This is the first report of a PVY natural infection on S. elaeagnifolium in Tunisia. The abundance of this weed, its over‐wintering status and the high rate of PVY‐infected plants (31.9%) allow us to deduce that S. elaeagnifolium must be considered a reservoir species of PVY under natural conditions in Tunisia and probably in other Mediterranean countries. The presence of efficient aphid vectors of PVY on this weed in crops is additional evidence that S. elaeagnifolium may become a problem by acting as a source plant for PVY spread in potato crops.     

Epitrix similaris and Epitrix cucumeris in Portugal: damage patterns in potato and suitability of potential host plants for reproduction

The potato flea beetle species Epitrix similaris and Epitrix cucumeris were identified in mainland Portugal in 2009. This was the first finding of the species E. similaris in the EPPO region, and the first report of the species E. cucumeris, established in the Atlantic Islands of Azores (Portugal) for three decades, in the mainland EPPO zone. Preliminary information on the damage patterns caused by E. similaris and E. cucumeris on potato and their host plant preferences is provided. Leaf feeding by the adults causes the characteristic shot‐hole pattern common to flea beetles. The larvae of both species develop on the root system and cause damage to the tubers. In field experiments, tuber damage by E. similaris presented three patterns: superficial tracks (serpentines), black splinters, and shallow holes. In the laboratory E. cucumeris was observed to be able to feed on very small immature tubers, causing serpentines and holes as well. However, in some cases it developed exclusively on roots. The adults of both Epitrix species hardly fed and reproduced on sweet pepper plants but fed and reproduced on the remaining five solanaceous plants tested (aubergine, Datura stramonium, tomato, potato and Solanum nigrum). E. similaris produced a much higher number of progeny on potato and on S. nigrum than on the other host plants. E. cucumeris produced more offspring on S. nigrum than on the other host‐plants.     

Genetic diversity of Solanum elaeagnifolium,an invasive problematic weed in Jordan

Solanum elaeagnifolium (silverleaf nightshade) is a problematic weed that is common in Jordan and difficult to control. The weed exhibits distinct morphological variations in growth habit, leaf shape, leaf margins, flower colour and presence or absence of spines between individuals among and within populations suggesting genetic differences. Genetic variations among 61 samples of S. elaeagnifolium collected from heavily infested sites in the central Jordan Valley were investigated using six simple sequence repeat (SSR) markers and eight amplified fragment length polymorphism (AFLP) primer combinations. Results showed that 111 out of 675 AFLP bands were polymorphic generating polymorphism information content (PIC) of 38.0%, while 23 SSR polymorphic alleles were detected generating a PIC of 30.8%. Phylogenetic analysis using RaxML software identified four major clades with a clear clustering of the samples with their collection sites. Genetic analysis using both techniques revealed high level of genetic diversity among S. elaeagnifolium samples collected from a small geographical area indicating that a range of genetic diversity may be detected in weed populations across the country that may complicate its management.     

PM 7/39 (2) Aphelenchoides besseyi

Specific scope

This Standard describes a diagnostic protocol for Aphelenchoides besseyi. This Standard should be used in conjunction with PM 7/76 Use of EPPO diagnostic protocols. Terms used are those in the EPPO Pictorial Glossary of Morphological Terms in Nematology a .

Specific approval and amendment

Approved in 2003‐09. Revised in 2017‐04. This revision was prepared on the basis of the IPPC Diagnostic Protocol adopted in 2016 on Aphelenchoides besseyi, Aphelenchoides fragariae and Aphelenchoides ritzemabosi (Annex 17 to ISPM 27; IPPC, 2016 ). The EPPO Diagnostic Protocol only covers A. besseyi. It differs in terms of format but it is consistent with the content of the IPPC Standard for morphological identification for this species. With regard to molecular methods, one real‐time PCR test available in the region is included as well as DNA barcoding.     

Invasive weed facilitates incidence of Colorado potato beetle on potato crop

We examined whether the invasive silverleaf nightshade, Solanum elaeagnifolium (Cavanilles) can facilitate the infestation of potato (Solanum tuberosum (L.)) by the Colorado Potato Beetle, CPB, Leptinotarsa decemlineata (Say) in Greece, which would have important financial and pest management implications for the growing of potato crops. In laboratory tests, CPB from Lesvos could utilise S. elaeagnifolium if supplied with whole plants. In the field, however, CPB was only found on S. elaeagnifolium after the start of the spring potato harvest and the resulting loss of potato foliage, and no eggs were laid. This suggests that S. elaeagnifolium provides only a temporary food resource for adult beetles. One of 10 surveyed summer potato fields near the study population of S. elaeagnifolium was infested with CPB. It is likely that the presence of S. elaeagnifolium in the vicinity of spring and summer potato fields can help maintain CPB population viability in the immediate post harvest period of the spring potato crop, which may in turn facilitate the infestation of summer potato fields with CPB.     

PM 7/87 (2) Ditylenchus destructor and Ditylenchus dipsaci

Specific scope

This Standard describes a diagnostic protocol for Ditylenchus destructor and Ditylenchus dipsaci. 1 This Standard should be used in conjunction with PM 7/76 Use of EPPO diagnostic protocols. Terms used are those in the EPPO Pictorial Glossary of Morphological Terms in Nematology. 2

Specific approval and amendment

Approved in 2008‐09. This revision was prepared on the basis of the IPPC Diagnostic Protocol adopted in 2015 on D. dipsaci and D. destructor (Annex 8 to ISPM 27 Diagnostic protocols for regulated pests). The EPPO Diagnostic Protocol is consistent with the text of the IPPC Standard for morphological identification for this species. For comparison with other species the IPPC table includes Ditylenchus africanus whereas the EPPO table includes Ditylenchus convallariae due to the different distribution of the species. The molecular tests for which there is experience in the EPPO region are described in full in the appendices (some of these are additional tests to those in the IPPC protocol). Reference is given to the IPPC protocol for tests for which there is little experience in the EPPO region. DNA barcoding is also included. Revision approved in 2017‐04.     

Morphological variation of Solanum elaeagnifolium in south‐eastern Australia

Solanum elaeagnifolium (silverleaf nightshade) is an invasive perennial weed in Australia, with aerial growth commencing in spring from either the perennial root system or the soil seedbank, with senescence occurring in autumn. A total of 642 S. elaeagnifolium individuals were collected at flowering from 92 locations in south‐eastern Australia to study morphological variation and its implications for management. Large morphological variation was found between individuals from different locations. Leaf length, width and area ranged from 1.44 to 10.6 cm, 0.39 to 4.09 cm and 0.41 to 25.8 cm² respectively. Plants from higher rainfall regions were significantly taller and had larger leaves, suggesting a possible correlation between rainfall and morphology. Scanning electron microscopy comparison of leaf surfaces showed lower trichome and stomatal densities on the adaxial surface (67.0 ± 3.3 trichomes mm^?2 and 603.4 ± 29.2 stomata mm^?2 respectively) than on the abaxial surface (131.9 ± 7.2 trichomes mm^?2 and 813.7 ± 30.5 stomata mm^?2 respectively). The morphological plasticity of S. elaeagnifolium highlighted in this study could probably contribute to its adaptability and partly explain its establishment and continuing expansion in Australia.     

Genetic variation and structure in native and invasive Solidago canadensis populations

Solidago canadensis is native to North America, but has become a noxious invasive plant in China. We know only a little about its invasion history and the effects of introductions on its genetic composition. Here, we investigated genetic variation and structure between 15 North American and 13 Chinese populations of S. canadensis using AFLP makers. Four AFLP loci suggested relatively high genetic diversity of this weed and similar genetic variation between the invasive range and the native range. Most genetic variation was within populations across two ranges, but the Chinese range had a higher degree of among‐population variation than the North American range. Multiple tests, including Bayesian assignment, UPGMA analysis, PCoA and analysis of ‘isolation by distance’, showed that the Chinese populations originated from at least two distinct native sources and that secondary introduction or dispersal should be common in China. Also, North American populations were possibly a single genetic group. Overall, S. canadensis in China was probably founded from multiple introductions and then spread through long‐distance dispersal associated with human activities. Genetic variability in the species in the invaded range appears to have favoured establishment and spread and may well provide a challenge to successful control.     

Meloidogyne luci,a new root‐knot nematode parasitizing potato in Portugal

In 2013, during a field survey conducted in Portugal on potato, Solanum tuberosum, an unusual esterase (EST) phenotype was detected in a root‐knot nematode (RKN) from potato roots collected in Coimbra. This Portuguese isolate was purified and maintained on tomato, S. lycopersicum, and morphological, biochemical and molecular characteristics were studied. Perineal pattern morphology was highly variable, similar to Meloidogyne ethiopica and not useful for identification. The EST phenotype, from young egg‐laying females, displayed three bands similar to the Brazilian M. luci (L3) and distinct from M. ethiopica (E3). Phylogenetic analyses of mitochondrial cytochrome oxidase subunit I and the mitochondrial DNA region between COII and 16S rRNA genes revealed that the Portuguese isolate grouped with M. luci isolates close to M. ethiopica isolates. However, considering the ITS1‐5.8S‐ITS2 region, the Portuguese isolate grouped with isolates of M. luci, M. ethiopica and M. hispanica, which limits the confidence of this region for M. luci diagnosis, and its differentiation from other species with morphological similarities. The M. luci pathogenicity to potato was also assessed in 16 commercial cultivars and compared with M. chitwoodi, considered to be a quarantine RKN species by EPPO. All potato cultivars were susceptible to both Meloidogyne species with gall indices of 5 and higher reproduction factor values ranging from 12.5 to 122.3, which suggests that M. luci may constitute a potential threat to potato production. In the present study, M. luci is reported for the first time attacking potato in Portugal.     

First record of fall armyworm (Spodoptera frugiperda) in Syria

The fall armyworm Spodoptera frugiperda is a lepidopteran pest that can damage and destroy a wide variety of crops. It is widely present in the Americans and has been invasive in Africa since 2016. Larvae of S. frugiperda were found for the first time in four rural farms on maize plants (Zea mays) located in Tafas town (Dara’a Governorate, in the south‐west of Syria) in November 2020. Infested maize showed the typical damage symptoms caused by S. frugiperda. Furthermore, morphological identification of larvae based on standard parameters of larvae confirmed the identity of the pest as fall armyworm. Considering the recent introduction of the pest into the EPPO region, it could be concluded that the pest probably entered Syria through natural spread (active flight and via wind currents) from Jordan, which borders Syria in the southern part and where the pest was found very recently.     

The psyllid Macrohomotoma gladiata Kuwayama, 1908 (Hemiptera: Psylloidea: Homotomidae): a Ficus pest recently introduced in the EPPO region

The psyllid Macrohomotoma gladiata, is a new insect pest of Ficus originating from Asia which has recently been found in Spain (Alicante) on urban Ficus microcarpa trees. This species may be of phytosanitary concern because of its leaf wrapping habits, wax secretion and honeydew excretion that may lead to direct and secondary twig damage. Although more studies are needed on the biology of M. gladiata, it is suspected that it might behave in the Euro‐Mediterranean as an invasive alien species. The predation by Anthocoris sp. (nemoralis?) needs to be investigated in order to assess its effectiveness as a natural biological control agent. This is the first report of M. gladiata from the EPPO region.     

Pest risk analysis and invasive alien plants: progress through PRATIQUE*

The EPPO Decision‐support scheme (DSS) for Pest Risk Analysis (PRA) was fundamentally revised by the PRATIQUE EU project. Based on the examples of Polygonum perfoliatum (mile‐a‐minute‐weed) and Eichhornia crassipes (water hyacinth), its applicability for invasive alien plants was tested. By means of a comparison of the risk analysis procedures with EPPO schemes before and after the project, pest group specific enhancements are outlined. For the two plants tested here, documented invasion history as well as biotic and abiotic requirements show that they can establish and spread in Europe and cause damage. PRATIQUE revisions to the EPPO DSS increased transparency, user friendliness and consistency for PRAs on invasive alien plants. This was accomplished through more comprehensive rating guidance, and aspects such as allowing individual risk elements to be documented and summarized to give a conclusive end result.     

The invasive Impatiens glandulifera Royle (Himalayan balsam) in the Republic of Macedonia: first record and forecast

A population of Impatiens glandulifera Royle, an invasive plant species native to the Western Himalayas, was recorded in 2013 near the village Gorno Sedlarce in the north‐western mountainous region of the Republic of Macedonia. I. glandulifera is a new alien species to the Macedonian flora. The surveys revealed an intensive growth and a low to medium density population of I. glandulifera. The population's density was not quantified, but several stands of different sizes were found. A rapid ecological risk assessment, mainly based on knowledge about invasion histories in North–Western and Central European countries, showed that this species, which is on the EPPO List of Invasive Alien Plants, is a serious threat to Macedonian biodiversity. Biological invasions of I. glandulifera affect biodiversity worldwide, and, consequently, the invaded ecosystems may experience significant losses in economic and cultural values. There is a clear need to develop a strategy for control of I. glandulifera to protect biodiversity, as a whole.     

Effect of ensiling and in sacco digestion on the viability of seeds of selected weed species

The germinability and viability of mature seeds of five grass (Hordeum spp., Bromus diandrus, Vulpia spp., Avena fatua and Lolium rigidum) and seven broad‐leaved weed species (Echium spp., Physalis hederifolia, Solanum elaeagnifolium, Raphanus raphanistrum, Marrubium vulgare and Malva parviflora) that were either untreated, ensiled for a minimum of three months, underwent 48 h in sacco digestion in steers or ensiled prior to digestion were tested for germinability and viability. Ensiling and digestion both reduced seed viability, although the extent varied with species. The effect of ensiling was generally greater compared with digestion and differed between years for some species. Ensiling or ensiling plus digestion rendered all seeds of Hordeum spp., B. diandrus, Vulpia spp., A. fatua, Echium spp., P. hederifolia (in one year only), S. elaeagnifolium, R. raphanistrum and M. vulgare non‐viable; ensiling and ensiling plus digestion reduced viability of L. rigidum by 74.4% and 92.7% respectively. Viability of M. parviflora displayed the greatest tolerance to damage, with seed viability reduced on average by 31.4%, 27.6% and 27.4% for ensiling, digestion and ensiling plus digestion treatments respectively. These results indicate that ensiling can provide an effective non‐chemical weed management option, as a component of an integrated weed management package, for certain weed species responsible for significant crop and pasture production losses in Australian and world temperate and Mediterranean agricultural systems.