European and Mediterranean Plant Protection Organization Organisation Européenne et Méditerranéenne pour la Protection des Plantes 11-16828 PEST RISK ANALYSIS FOR : Ludwigia peploides A Draft PRA had been prepared by Mr Guillaume Fried, and the Expert Working Group was attended by the following experts: Mr Mustafa Selçuk Basaran, Plant Protection Central Research Institute, Turkey Mr Alain Dutartre, CEMAGREF, France Mr Guillaume Fried, LNPV Station de Montpellier, France Mr Jonathan Newman, Waterland Management Ltd, United Kingdom Mr Uwe Starfinger, Julius Kühn Institute, Germany Mr Johan van Valkenburg, Plant Protection Service, The Netherlands. EPPO Secretariat: Ms Sarah Brunel Peer review has been undertaken by Ms Schrader, Julius Kühn Institute, Germany. Flower of Ludwigia peploides, by Franck Billeton Stage 1: Initiation 1 - Give the reason for performing the PRA Identification of a single pest L. peploides is widespread and invasive in the South-East and West of France and its distribution is still very limited in Belgium, Corsica, Greece, Italy, the Netherlands, Spain, Turkey, and the UK where invasions are at an early stage. The species could spread to further EPPO countries and have negative impacts on agriculture and the environment. 1b - If other reason, specify 2a - Enter the name of the pest Pest name (what you enter here will appear as a heading) Ludwigia peploides (Kunth) P.H. Raven The identification of Ludwigia species of the section Oligospermum s.l. has always been very difficult and resulted in unending taxonomic changes and inextricable synonymy (Dandelot et al., 2005a). The L. uruguayensis complex comprises a decaploid entity (2n = 80) and a hexaploid one (2n = 48), differing by quantitative, intergrading morphological features, known to produce hybrids of intermediary morphology in regions of sympatry (Nesom & Kartesz, 2000). Ludwigia peploides is ressembling and often confused with L. grandiflora, which often occur together in countries. Publications therefore often mention “Ludwigia spp.”. 2b - Indicate the type of the pest Non parasitic plant Perennial aquatic freshwater plant (amphibious hydrophyte, macrophyte). 2c - if other, specify 2d - Indicate the taxonomic position Kingdom: Plantae Class: Magnoliopsida (Dicotyledons) Subclass: Rosidae Order: Myrtales Family: Onagraceae 3 - Clearly define the PRA area The EPPO region. 4 - Does a relevant earlier PRA exist? Yes An EPPO Pest Risk Analysis has been performed for Ludwigia grandiflora. Reference will often be made to the PRA for L. grandiflora in the current PRA. Plant assessment forms have been produced in California for Ludwigia peploides subsp. montevidensis (Trumbo & DiTomaso, 2004) using the Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands (Warner et al., 2003). A risk assessment has also been carried out for Great Britain for L. grandiflora, L. hexapetala and L. peploides (DEFRA, 2008). 5 - Is the earlier PRA still entirely valid, or only partly valid (out of date, applied in different circumstances, for a similar but distinct pest, for another area with similar conditions)? Not entirely valid 5b - Explain The EPPO PRA for Ludwigia grandiflora has broad similarities to this PRA, and where necessary is referred to. 6 - Specify all host plant species (for pests directly affecting plants) or suitable habitats (for non parasitic plants). Indicate the ones which are present in the PRA area. In its native range, L. peploides is reported in wetlands (Rolon et al., 2008), in the transition zone-between aquatic and terrestrial environments (Hernandez & Rangel, 2009). Establishment of L. peploides often occurs on mud in open areas of wetlands subject to fluctuating water levels (natural or managed); in disturbed marginal habitats subject to grazing, i.e. meadows (cattle, wild geese) or management. The latter can include sites where restoration for conservation or reinstatement of aquatic habitats occurs, especially where the margins have a gradual slope. Suitable habitats include wet margins of ponds and lakes, static or slow-flowing waters, rivers, shallow ponds and lakes, canals, oxbow lakes, wetlands, ditch networks. It is also found on sediment bars on river borders and in wet meadows (Laugareil, 2002 ; Zotos et al., 2006), and can also colonize brackish waters (Mesleard & Perennou, 1996). 7 - Specify the pest distribution Native range : - Central America: Cuba, Costa Rica, Dominican Republic, El Salvador, Guatemala, Haiti; Honduras, Jamaica, Nicaragua; Panama, Puerto Rico . - South America: Argentina, Bolivia, Brazil, Colombia, Ecuador, Paraguay, Peru, Uruguay, Venezuela, Note: L. peploides in Argentina is known to occur in Buenos Aires, Corrientes, Entre Rios, Formosa, Mendoza, Salta, Santa Fe, Tucuman. - North America : United States (Alabama, Arkansas, California, Florida, Georgia, Indiana, Illinois, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Nebraska, North Carolina, Oklahoma, , South Carolina, Tennessee, Texas), Mexico. Note: The EWG considered the proliferation of subspecies and varietal names in North America associated with supposed native status to be unhelpful. However, it is clear that L. peploides is probably native to most States where it is found in North-America. Introduced Range : EPPO Region: Belgium (Branquart et al., 2010), France (Dutartre et al., 2007) including Corsica (Jeanmonod & Schlüssel, 2007), Greece (Zotos et al., 2006), Italy (Celesti-Grapow et al., 2009), the Netherlands (Holverda et al. 2009), Spain (Verloove & Sánchez Gullón, 2008), Turkey (near Antalya) (Güner et al., 2000), the UK (BSBI, 2011). Australasia: Australia (New South Wales, Northern Territory, Queensland, South Australia, Victoria) (Richardson et al., 2007; Australia’s Virtual Herbarium, 2011), New Zealand (north island) (Webb et al., 1988; Roy et al., 2004). Africa: Madagascar (GBIF Portal, 2011) Asia: Thailand, Taiwan (GBIF Portal, 2011). In Belgium L. peploides was first observed in Belgium in 1995 (Branquart et al., 2010), and has established isolated populations in Flanders. In France L. peploides and L. grandiflora are very widespread in hundreds of sites in Southern and Western France and more recently recorded spreading in some sites in North and East of France (Dutartre, 2004a, see map in Appendix 1). In Corsica, L. peploides has been found in another site, near the golf course of Lezza where it is cultivated for ornamental purposes. The species grows in the river, and has not outcompeted the existing vegetation, probably because the water course is only temporary, not allowing the species to exhibit invasive behavior (Jeanmonod & Schlüssel, 2007). In Greece L. peploides was recorded in 2001 in western Greece in 3 localities of the lake Lysimachia, covering a very small area (0.7 ha), representing a population of 10 000 individuals. In Italy The species occurs in Lombardia and is even considered as invasive in the provinces of Cremona and Lodi (Banfi & Galasso, 2010). The species is also reported in Emilia-Romagna, and was first recorded in Italy in 2004 by Petraglia and Antoniotti (Galasso & Bonali, 2007) In the Netherlands In the Netherlands, L. peploides was found in 4 sites, the first offical records are dated 2007 (but further analyses highlighted that plants identified as L. grandiflora were indeed L. peploides, J van Valkenburg, pers. comm., 2011). It disappeared from one site without any action. It was successfully removed from another site by the water board. A third infestation covering several hundred square meters was removed in 2007, and regrowth has not been observed since (June 2010). One other site is under management (Proosdij & van Valkenburg, in prep.). In Spain According to Verloove & Gullon (2008), Ludwigia peploides has been recorded to be well naturalized at various localities along river El Llobregat in the province of Barcelona, and it also recorded in La Selva del mar in the Province of Gerona. In the UK In the UK, the species was reported to be present in 3 locations in Southern Great Britain in 2006 (DEFRA, 2006). Stage 2: Pest Risk Assessment - Section A : Pest categorization init - - Go to main Pest Risk Assessment L. peploides has been considered as having high impact on agriculture and the environment by the EPPO prioritization process (Description of the EPPO priotization process Brunel et al., 2010). Stage 2: Pest Risk Assessment - Section B : Probability of entry of a pest 1.1 - Consider all relevant pathways and list them (one by line) Relevant pathways are those with which the pest has a possibility of being associated (in a suitable life stage), on which it has the possibility of survival, and from which it has the possibility of transfer to a suitable host. Make a note of any obvious pathways that are impossible and record the reasons. There are broad similarities in answers to this question in the PRA for L. grandiflora, but see the additional comments below: Intentional import as an ornamental aquatic plant for use outdoors: As for L. grandiflora, the plant is considered to be introduced as an ornamental aquatic plant. There is no data available on numbers of the species imported, but the species is still sold in EPPO countries, in most cases under misapplied names such as Jussiaea or Ludwigia grandiflora (Dandelot, 2004). The species is already present in Belgium, France, Greece, Italy, Spain, Turkey, the Netherlands, and theUK . Although regulated in some countries, the probability of entry of intentional import as an ornamental aquatic plant for use outdoors