Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide


Meloidogyne fallax
(false Columbia root-knot nematode)



Meloidogyne fallax (false Columbia root-knot nematode)


  • Last modified
  • 14 July 2018
  • Datasheet Type(s)
  • Invasive Species
  • Pest
  • Preferred Scientific Name
  • Meloidogyne fallax
  • Preferred Common Name
  • false Columbia root-knot nematode
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Metazoa
  •     Phylum: Nematoda
  •       Family: Meloidogynidae
  •         Genus: Meloidogyne
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Preferred Scientific Name

  • Meloidogyne fallax Karssen, 1996

Preferred Common Name

  • false Columbia root-knot nematode

Other Scientific Names

  • Meloidogyne chitwoodi (Baexem) B-type van Meggelen et al., 1994

Local Common Names

  • Netherlands: bedrieglijk maiswortelknobbel nematode

EPPO code

  • MELGFA (Meloidogyne fallax)

Taxonomic Tree

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  • Domain: Eukaryota
  •     Kingdom: Metazoa
  •         Phylum: Nematoda
  •             Family: Meloidogynidae
  •                 Genus: Meloidogyne
  •                     Species: Meloidogyne fallax

Notes on Taxonomy and Nomenclature

Top of page This species was previously referred to as Meloidogyne chitwoodi (Baexem) B-type, described by van Meggelen et al. (1994), and was descibed as a separate species by Karssen (1996). It was first isolated in a field plot experiment conducted near Baexem, in the Netherlands. The host crop in this case, Zea mays, a good host for M. chitwoodi, was in fact recorded as a non- to poor host. A critical re-examination of second-stage juveniles, compared with M. chitwoodi paratypes, indicated differences in body, tail and hyaline tail terminus length. In the autumn of the same year, the Baexem population was studied biochemically, and a unique malate dehydrogenase (MDH) pattern was detected.


Top of page Adult males and the second-stage juveniles are vermiform, motile and similar in appearance to free-living soil nematodes. Females are characteristically pear-shaped, pearly-white and sedentary. The male is 736-1520 µm in length and 27-44 µm in width with a slight taper at each end. The tail measures 7.6-12.1 µm long and is twisted. Cuticular annules are distinct. The female is 404-720.3 µm long and 256-464 µm wide. Second-stage juveniles are 381-435.2 µm long and 13-16.4 µm wide; tail length is 46-55.6 µm with a broadley rounded tail terminus and smooth hyaline tail terminus. Eggs are 89-103.6 µm in length and 34-44.2 µm wide.


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In Europe, the known distribution of M. fallax is restricted to the south-eastern part of the Netherlands, western France and Belgium (first reported in 1997; EPPO, 2003). It has been reported from potato in Australia (Nobbs et al., 2001), potato in New Zealand (Marshall et al., 2001) and South Africa (Fourie et al., 2001), although the latter record, which was based on SCAR-PCR, may be unreliable.

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes


South AfricaAbsent, unreliable recordFourie et al., 2001; CABI/EPPO, 2003; EPPO, 2014

North America

USAAbsent, confirmed by surveyUSDA-APHIS, 2014, personal communication; EPPO, 2014
-CaliforniaAbsent, confirmed by surveyUSDA-APHIS, 2014, personal communication; EPPO, 2014


BelgiumPresentWayenberge and Moens, 2001; CABI/EPPO, 2003; EPPO, 2014
BulgariaAbsent, confirmed by surveyEPPO, 2014
FranceRestricted distributionCABI/EPPO, 2003; EPPO, 2011; EPPO, 2014
GermanyTransient: actionable, under eradicationCABI/EPPO, 2003; EPPO, 2014
NetherlandsRestricted distributionNPPO of the Netherlands, 2013; Karssen, 1996; CABI/EPPO, 2003; EPPO, 2014
SwitzerlandPresent, few occurrencesEPPO, 2011; EPPO, 2014EPPO Reporting Service No. 2011/151. Detected in a small number of production sites (glasshouses and heated plastic tunnels) near Saillon (Valais), under eradication.
UKRestricted distributionEPPO, 2014
-England and WalesRestricted distributionEPPO, 2014
-Northern IrelandRestricted distributionEPPO, 2014


AustraliaRestricted distributionNobbs et al., 2001; CABI/EPPO, 2003; EPPO, 2014
-South AustraliaPresentNobbs et al., 2001; CABI/EPPO, 2003; EPPO, 2014
-TasmaniaPresentHay and Pethybridge, 2005
-VictoriaPresentNambiar et al., 2008; EPPO, 2014
New ZealandPresentNobbs et al., 2001; CABI/EPPO, 2003; EPPO, 2014; Rohan et al., 2016

Risk of Introduction

Top of page M. fallax has been recommended for addition to the EC Plant Health Directive 77/93/EEC.

Hosts/Species Affected

Top of page Meloidogyne fallax has been mainly recorded on potato, oyster plant (Scorzonera hispanica) and carrot. The only published work on its host range appears to be that by Brinkman et al. (1996). Good hosts for this species include Oenothera erythrosepala, Phacelia tanacetifolia, Dicentra spectabilis and Hemerocallis cv. Rajah; M. chitwoodi reproduces poorly or not at all on these. Conversely, Phaseolus vulgaris cvs. Iprin, Strike and Groffy, Zea mays, Potentilla fructicosa and Erica cinerea seem to be poor hosts for M. fallax but good hosts for M. chitwoodi. Sommen et al. (2005) recorded four strawberry cultivars as a host, although typical root-knot symptoms were not always present.

Growth Stages

Top of page Pre-emergence, Seedling stage, Vegetative growing stage


Top of page Symptoms are very similar to those caused by M. chitwoodi; above ground symptoms are often hard to differentiate and infested roots often do not show the galling which is typical of other Meloidogyne species. Infested potato tubers may have small raised swellings on their surface above the developing nematodes. Adult females are visible just below the surface; when alive they appear as glistening, white, pear-shaped bodies surrounded by a brownish layer of host tissue. As the female matures and dies, the egg-filled sac becomes dark-brown with age.

In general, it appears that M. fallax can cause more severe symptoms than M. chitwoodi, but there is little published information to date.

List of Symptoms/Signs

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SignLife StagesType
Leaves / wilting
Leaves / yellowed or dead
Vegetative organs / surface lesions or discoloration
Whole plant / dwarfing

Biology and Ecology

Top of page Little has been published on the biology and ecology of this pest, apart from its host range. At present, control measures are based on the biology of M. chitwoodi.

Natural enemies

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Natural enemyTypeLife stagesSpecificityReferencesBiological control inBiological control on
Myrothecium verrucaria Pathogen
Pasteuria nishizawae Pathogen
Pasteuria penetrans Pathogen

Pathway Vectors

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VectorNotesLong DistanceLocalReferences
Clothing, footwear and possessionsEggs and juveniles in soil. Yes
Containers and packaging - woodEggs and juveniles in soil. Yes
Land vehiclesEggs and juveniles in soil. Yes
Soil, sand and gravelEggs and juveniles in soil. Yes

Plant Trade

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Plant parts liable to carry the pest in trade/transportPest stagesBorne internallyBorne externallyVisibility of pest or symptoms
Growing medium accompanying plants adults; eggs; juveniles Yes Pest or symptoms not visible to the naked eye but usually visible under light microscope
Roots adults; eggs; juveniles Yes Yes Pest or symptoms not visible to the naked eye but usually visible under light microscope
Seedlings/Micropropagated plants adults; eggs; juveniles Yes Yes Pest or symptoms not visible to the naked eye but usually visible under light microscope
Plant parts not known to carry the pest in trade/transport
Fruits (inc. pods)
Stems (above ground)/Shoots/Trunks/Branches
True seeds (inc. grain)


Top of page In the Netherlands, M. fallax is a pest of economic importance on potatoes, oyster plant (black salsify; Scorzonera hispancia) and carrots. On a single site in France it was found causing damage to tomatoes, and tests indicated that it has a greater effect on yields of lettuce and artichoke than M. chitwoodi. Korthals et al. (2000) discussed its impact on potato production.


Top of page Morphological methods have been used in conjunction with esterase and malate dehydrogenase patterns (Karssen, 1994; van Meggelen et al., 1994) and DNA methods (Petersen and Vrain, 1996; Zijlsta et al., 1996; Castagnone-Sereneo et al., 1998, 1999; Castagnone-Sereno, 2000; Ziljstra, 2000; Fourie et al., 2001; Wishart et al., 2002; Fargette et al., 2005) to confirm diagnosis. Diagnostic protocols were published by Anon. (1999, 2004).

Detection and Inspection

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Detection and inspection methods are similar to those for M. chitwoodi. The presence of M. fallax in infested soil can be determined by sampling and extraction of the second-stage juveniles, using a standard nematode extraction procedure for free-living nematodes of this size. External symptoms on tubers are obvious in the case of heavy infestations but, where nematode numbers are low or in the early stages of infection, such symptoms are not obvious. Clearing and staining of the tissues can show the presence of nematodes (Hooper, 1986) but this can be a laborious procedure. Storage of lightly infested tubers may lead to the development of obvious external symptoms.  Detection based on host plant symptoms and identification by morphological and molecular methods are detailed in OEPP/EPPO (2009).

Similarities to Other Species/Conditions

Top of page M. fallax closely resembles M. chitwoodi; it can be distinguished by greater female and male stylet length, absence of small, irregular outlined male and female stylet knobs (Eisenback and Hirschmann, 1991), male labial disc elevated, longer juvenile body-, tail-, and hyaline tail length, different hyaline tail shape, and hemizonoid position. It differs from M. hapla by the absence of fine, smooth striae, rounded and flattened dorsal arch and tail area punctations in the female perineal pattern, broader J2 tail and tail terminus with distinct hyaline part, shorter female and male stylet length, and the absence of small rounded stylet knobs.

Prevention and Control

Top of page Research is being undertaken to develop varieties of potato resistant to M. fallax (Janssen et al., 1996a,b; 1997). Studies have also been undertaken to identify possible rotation alternatives and to reduce nematode populations (Brinkman et al., 1996). For instance, it appears that Phaseolus vulgaris (except cv. Masai) is not a good host for M. fallax. Wishart et al. (2004) reported the attachment of spores of Pasteuria penetrans and P. nishizawae, potential biological control agents, to juveniles of M. fallax. Zoon et al. (2002) investigated durable resistance against M. fallax whilst Kouassi et al. (2004) studied the resistance mechanism to M. fallax in Solanum sparsipilum.


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Anon, 1999. Meloidogyne fallax. Bulletin OEPPO, 29(4): 493-496.

Anon, 2005. Meloidogyne chitwoodi and Meloidogyne fallax. Bulletin OEPP, 34(2): 315-320.

Brinkman H; Goossens JJM; Riel HRvan, 1996. Comparative host suitability of selected crop plants to Meloidogyne chitwoodi Golden et al. 1980 and M. fallax Karssen 1996. Anzeiger fu^umlaut~r Scha^umlaut~dlingskunde, Pflanzenschutz, Umweltschutz, 69(6):127-129; 13 ref.

CABI/EPPO, 2003. Meloidogyne fallax. Distribution Maps of Plant Diseases, No. 901. Wallingford, UK: CAB International.

Castagnone-Sereno P, 2000. Use of satellite DNA for specific diagnosis of the quarantine root-knot nematodes Meloidogyne chitwoodi and M. fallax. Bulletin OEPP, 30(3/4):581-584; 11 ref.

Castagnone-Sereno P; Leroy F; Bongiovanni M; Zijlstra C; Abad P, 1999. Specific diagnosis of two root-knot nematodes, Meloidogyne chitwoodi and M. fallax, with satellite DNA probes. Phytopathology, 89(5):380-384; 21 ref.

Castagnone-Sereno P; Semblat JP; Leroy F; Abad P, 1998. A new AluI satellite DNA in the root-knot nematode Meloidogyne fallax: relationships with satellites from the sympatric species M. hapla and M. chitwoodi. Molecular Biology and Evolution, 15(9):1115-1122; 37 ref.

Eisenback JD; Hirschmann H, 1991. Root-knot nematodes: Meloidogyne species and races. In: Nickle WR, ed. Manual of Agricultural Nematology. New York, USA: Marcel Dekker, 191-274.

EPPO, 1997. Selected items from the EPPO Reporting Service of January 1997. EPPO Reporting Service, 97/001-97/003.

EPPO, 2009. Meloidogyne chitwoodi and Meloidogyne fallax. Bulletin OEPP/EPPO Bulletin, 39(1):5-17.

EPPO, 2011. EPPO Reporting Service. EPPO Reporting Service. Paris, France: EPPO.

EPPO, 2014. EPPO Reporting Service, No. 2014/008. Paris, France: European and Mediterranean Plant Protection Organization.

EPPO, 2014. PQR database. Paris, France: European and Mediterranean Plant Protection Organization.

Fargette M; Lollier V; Phillips M; Blok V; Frutos R, 2005. AFLP analysis of the genetic diversity of Meloidogyne chitwoodi and M. fallax, major agricultural pests. Comptes Rendus Biologies, 328(5):455-462.

Fourie H; Zijlstra C; McDonald AH, 2001. Identification of root-knot nematode species occurring in South Africa using the SCAR-PCR technique. Nematology, 3(7):675-680; 11 ref.

Hay FS; Pethybridge SJ, 2005. Nematodes associated with carrot production in Tasmania, Australia, and the effect of Pratylenchus crenatus on yield and quality of Kuroda-type carrot. Plant Disease, 89(11):1175-1180. HTTP://

Hooper DJ, 1986. Preserving and staining nematodes in plant tissues. In: Southey JF, ed. Laboratory methods for work with plant and soil nematodes. London, UK: HMSO.

Janssen GJW; Janssen R; Norel Avan; Verkerk-Bakker B; Hoogendoorn J, 1996. Expression of resistance to the root-knot nematodes, Meloidogyne hapla and M. fallax, in wild Solanum spp. under field conditions. European Journal of Plant Pathology, 102(9):859-865; 21 ref.

Janssen GJW; Norel Avan; Janssen R; Hoogendoorn J, 1997. Dominant and additive resistance to the root-knot nematodes Meloidogyne chitwoodi and M. fallax in Central American Solanum species. Theoretical and Applied Genetics, 94(5):692-700; 31 ref.

Janssen GJW; Norel Avan; Verkerk-Bakker B; Janssen R, 1996. Resistance to Meloidogyne chitwoodi, M. fallax and M. hapla in wild tuber-bearing Solanum spp. Euphytica, 92(3):287-294; 22 ref.

Karssen G, 1994. The use of isozyme phenotypes for the identification of root-knot nematodes (Meloidogyne species). Versl. Meded. plziektenk. Dienst Wageningen (Ann. Rep. Diagnostic Center), 170:85-88.

Karssen G, 1996. Description of Meloidogyne fallax n. sp. (Nematoda : Heteroderidae), a root-knot nematode from The Netherlands. Fundamental and Applied Nematology, 19(6):593-599; 14 ref.

Korthals GW; Brommer E; Molendijk LPG, 2000. Meloidogyne chitwoodi and Meloidogyne fallax a threat to potato production?. World potato congress: Proceedings of the Fourth World Potato Congress, Amsterdam, The Netherlands, 4-6 September, 2000, 207-208.

Kouassi AB; Kerlan MC; Sobczak M; Dantec JP; Rouaux C; Ellisseche D; Mugniery D, 2004. Resistance to the root-knot nematode Meloidogyne fallax in Solanum sparsipilum: analysis of the mechanisms. Nematology, 6(3): 389-400.

Marshall JW; Zijlstra C; Knight KWL, 2001. First record of Meloidogyne fallax n New Zealand. Australian Plant Pathology, 30(3): 283-284.

Meggelen JCvan; Karssen G; Janssen GJW; Verkerk-Bakker B; Janssen R, 1994. A new race of Meloidogyne chitwoodi Golden, O'Bannon, Santo & Finley, 1980?. Fundamental and Applied Nematology, 17(1):93; 5 ref.

Nambiar L; Quader M; Nobbs JM; Cobon JA; Campbell PR; Gulino LM, 2008. First record of Meloidogyne fallax in Victoria, Australia. Australasian Plant Disease Notes, 3(1):141-142.

Nobbs JM; Liu Q; Hartley D; Handoo Z; Williamson VM; Taylor S; Walker G; Curran J, 2001. First record of Meloidogyne fallax in Australia. Australaian Plant Pathology, 30(4): 373.

Petersen DJ; Vrain TC, 1996. Rapid identification of Meloidogyne chitwoodi, M. hapla, and M. fallax using PCR primers to amplify their ribosomal intergenic spacer. Fundamental and Applied Nematology, 19(6):601-605; 23 ref.

Rohan TC; Aalders LT; Bell NL; Shah FA, 2016. First report of Melodogyne fallax hosted by Trifolium repens (white clover): implications for pasture and crop rotations in New Zealand. Australasian Plant Disease Notes, 11(1):14.

Sommen AT van der; Nijs LJMF den; Karssen G, 2005. The root-knot nematode Meloidogyne fallax on strawberry in the Netherlands. Plant Disease, 89(5): 526.

Wayenberge L; Moens M, 2001. Meloidogyne chitwoodi and M. fallax in Belgium. Nematologia Mediterranea, 29(1): 91-97.

Wishart J; Blok VC; Phillips MS; Davies KG, 2004. Pasteuria penetrans and P. nishizawae attachment to Meloidogyne chitwoodi, M. fallax and M. hapla. Nematology, 6(4): 507-510.

Wishart J; Phillipa MS; Blok VC, 2002. Ribosomal intergenic spacer: a polymerase chain reaction diagnostic for Meloidogyne chitwoodi, M. fallax and M. hapla. Phytopathology, 92(8): 884-892.

Zijlstra C, 2000. Reliable identification of the quarantine root-knot nematodes Meloidogyne chitwoodi and M. fallax by PCR-based techniques. Bulletin OEPP, 30 (3/4): 575-579.

Zijlstra C; Uenk BJ; Silfhout CHvan, 1997. A reliable, precise method to differentiate species of root-knot nematodes in mixtures on the basis of ITS-RFLPs. Fundamental and Applied Nematology, 20(1):59-63; 17 ref.

Zoon FC; Golinowski W; Janssen R; Mugniery D; Phillips MS; Schlathoelter M; Smant G; Kruijssen lL van; Beek JG van der, 2002. Durable resistance against Meloidogyne chitwoodi and M. fallaz. Plant Protection Science, 38: 711-713.

Distribution Maps

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