Preferred name: Ditylenchus dipsaci
Authority: (Kuehn) Filipjev
Taxonomic position: Animalia: Nematoda: Chromadorea: Rhabditida: Anguinidae
Other scientific names: Anguillulina dipsaci Kuehn, Ditylenchus allii (Beijerinck) Tarjan, Ditylenchus fragariae Kirjanova, Ditylenchus phloxidis Kirjanova, Tylenchus allii Beijerinck, Tylenchus devastator (Kuehn) Oerley, Tylenchus dipsaci (Kuehn) Bastian
Common names in English: bloat disease of onion, brown ring disease of hyacinth, bulb eelworm, ring disease of bulbs, stem and bulb eelworm, stem and bulb nematode, stem nematode
view more common names online...
EPPO Categorization: A2 list
EU Categorization: RNQP (Annex IV)
view more categorizations online...
EPPO Code: DITYDI

Ditylenchus dipsaci is known to infect over 500 different plant species, including many weeds. Up to 30 biological races of D. dipsaci have been identified based on their host preferences, forming a species complex (Sturhan et al., 2008). The race(s) that breed on rye, oats and onions seem to be polyphagous and can also infest several other crops, whereas those breeding on lucerne, Trifolium pratense and strawberries are virtually specific for their named hosts and seem to have relatively few alternative host plants. The tulip race will also infest Narcissus, whereas another race commonly found in Narcissus does not breed on tulip. According to Whitehead et al. (1987), the sugar beet race is polyphagous but cannot multiply on lucerne, whereas the lucerne race can reproduce on sugar beet. It is known that some of the races can interbreed and that their progeny has different host preferences. See also Sturhan (1969), Eriksson (1974). Recently, the giant race of D. dipsaci has been recognized as a distinct species and is now known as Ditylenchus gigas (Vovlas et al., 2011).

The main hosts are faba beans, garlic, Hyacinthus orientalis, leeks, lucerne, maize, Narcissus pseudonarcissus, oats, onions, peas, Phlox drummondii, P. paniculata, potatoes, rye, strawberries, sugar beet, tobacco, Trifolium pratense, T. repens, tulips. D. dipsaci has also been reported on carnations, celery, Hydrangea, lentils, oilseed rape, parsley, sunflower, wheat.

Host list: Acanthophyllum cerastioides, Aetheorhiza bulbosa, Aethusa cynapium, Agave amica, Agrostemma githago, Allium ampeloprasum, Allium ascalonicum, Allium caeruleum, Allium cepa, Allium fistulosum, Allium galanthum, Allium giganteum, Allium oreophilum, Allium porrum, Allium sativum, Allium schoenoprasum, Allium sphaerocephalon, Allium triquetrum, Allium tuberosum, Allium vavilovii, Allium vineale, Alopecurus geniculatus, Amaryllis sp., Amberboa moschata, Ambrosia artemisiifolia, Amsinckia menziesii var. intermedia, Anchusa arvensis, Anemone coronaria, Angelica archangelica, Anthoxanthum odoratum, Anthriscus sylvestris, Anthyllis vulneraria, Apera spica-venti, Apium graveolens, Arabidopsis thaliana, Arabis alpina, Arabis aubrietioides, Arenaria serpyllifolia, Armoracia rusticana, Arnoseris minima, Arrhenatherum elatius, Asparagus setaceus, Asphodeline lutea, Atriplex patula, Atriplex sp., Aubrieta deltoidea, Aucuba japonica, Avena byzantina, Avena fatua, Avena nuda, Avena sativa, Avena sterilis, Avena strigosa, Baccharis glutinosa var. glutinosa, Begonia tuberhybrida hybrids, Bellevalia romana, Bellis perennis, Beta vulgaris, Bouvardia longiflora, Brachypodium pinnatum, Brassica napus subsp. rapifera, Brassica napus, Brassica nigra, Brassica oleracea var. botrytis, Brassica oleracea var. capitata, Brassica oleracea var. gongylodes, Brassica oleracea, Brassica rapa, Bromus catharticus, Bromus inermis, Calceolaria integrifolia, Callistephus chinensis, Camelina sativa, Campanula persicifolia, Cannabis sativa, Capsella bursa-pastoris, Capsicum annuum, Cardamine pratensis, Carduus acanthoides, Carex sp., Carlina vulgaris, Centaurea cyanus, Centaurea jacea, Cerastium arvense, Cerastium holosteoides, Chelone glabra, Chenopodium album, Cicer arietinum, Cichorium intybus, Cirsium arvense, Cirsium oleraceum, Cirsium palustre, Cirsium tuberosum, Cirsium vulgare, Cirsium x tataricum, Colchicum autumnale, Colchicum sp., Colchicum speciosum, Colchicum x agrippinum, Coleus scutellarioides, Coleus sp., Collomia biflora, Collomia grandiflora, Consolida orientalis, Convallaria majalis, Convolvulus arvensis, Crepis biennis, Crepis capillaris, Crepis foetida, Crepis leontodontoides, Crepis vesicaria subsp. taraxacifolia, Crocus sativus, Cucumis sativus, Cyclamen persicum, Cyclamen sp., Cynara cardunculus, Cynosurus cristatus, Dactylis glomerata, Daucus carota, Delphinium trolliifolium, Dianthus barbatus, Dianthus caryophyllus, Dianthus deltoides, Dianthus plumarius, Digitalis ferruginea, Digitalis grandiflora, Digitalis parviflora, Digitalis purpurea, Digitaria sanguinalis, Dipsacus fullonum, Disa uniflora, Echinochloa crus-galli, Elymus repens, Equisetum arvense, Erechtites praealta, Eremurus stenophyllus, Erigeron annuus, Erigeron canadensis, Eriocapitella hupehensis, Erodium cicutarium, Erysimum bicolor, Erysimum x cheiri, Erysimum x marshallii, Fagopyrum esculentum, Fallopia convolvulus, Festuca rubra, Ficaria verna, Ficus elastica, Fragaria chiloensis, Fragaria moschata, Fragaria vesca, Fragaria x ananassa, Freesia refracta, Fumaria officinalis, Galanthus hybrids, Galanthus nivalis, Galeopsis ladanum subsp. angustifolia, Galeopsis ladanum, Galeopsis segetum, Galeopsis speciosa, Galeopsis tetrahit, Galinsoga parviflora, Galium aparine, Galium tricornutum, Geranium dissectum, Geranium molle, Gilia achilleifolia, Gladiolus dalenii, Gladiolus hybrids, Glebionis segetum, Glycine max, Goeppertia lindbergii, Gossypium sp., Gypsophila paniculata, Helenium sp., Helianthus annuus, Helianthus tuberosus, Helichrysum orientale, Helleborus orientalis, Hepatica americana, Hibiscus sp., Hibiscus trionum, Holcus lanatus, Holcus mollis, Hordeum vulgare, Hyacinthoides hispanica, Hyacinthoides non-scripta, Hyacinthus orientalis, Hyacinthus sp., Hydrangea macrophylla, Hyoscyamus niger, Hypochaeris radicata, Ipomoea batatas, Ipomopsis rubra, Iris sp., Isatis tinctoria, Ismene narcissiflora, Juncus bufonius, Kickxia spuria, Knautia arvensis, Kniphofia sp., Koeleria pyramidata, Lactuca canadensis, Lamium album, Lamium amplexicaule, Lamium purpureum, Lathyrus odoratus, Lathyrus sativus, Lavandula angustifolia, Leondoton hispidus subsp. hastilis, Leontodon hispidus, Leontodon incanus, Leontopodium nivale subsp. alpinum, Lepidium coronopus, Lepidium draba, Lepidium sativum, Lepidium virginicum, Leucanthemum vulgare, Liatris spicata, Lilium longiflorum, Lilium regale, Linaria vulgaris, Linum usitatissimum, Lipandra polysperma, Lolium multiflorum, Lolium perenne, Lolium pratense, Lupinus angustifolius, Lupinus luteus, Lycoris radiata, Lysimachia arvensis, Lysimachia sp., Manihot esculenta, Medicago falcata, Medicago lupulina, Medicago minima, Medicago orbicularis, Medicago polymorpha, Medicago sativa subsp. glomerata, Medicago sativa, Melampyrum arvense, Melilotus albus, Mentha arvensis, Mercurialis annua, Mollugo verticillata, Muscari botryoides, Muscari neglectum, Muscari sp., Myosotis arvensis, Myosotis discolor, Myosotis stricta, Myriophyllum verticillatum, Narcissus assoanus, Narcissus bulbocodium, Narcissus cyclamineus, Narcissus poeticus, Narcissus pseudonarcissus, Narcissus romieuxii, Narcissus sp., Narcissus tazetta, Narcissus x incomparabilis, Narcissus x odorus, Navarretia minima, Nerine sp., Nicotiana tabacum, Nuttallanthus canadensis, Odontites vernus, Oenothera fruticosa, Oenothera glazioviana, Oenothera perennis, Oenothera tetragona, Onobrychis viciifolia, Ornithogalum candicans, Ornithogalum sp., Ornithopus sativus, Orobanche crenata, Oxalis sp., Oxalis stricta, Paeonia officinalis, Panicum miliaceum, Papaver rhoeas, Papaver somniferum, Pastinaca sativa, Penstemon barbatus, Penstemon eatonii, Penstemon gentianoides, Penstemon hartwegii, Persicaria lapathifolia, Persicaria maculosa, Persicaria pensylvanica, Petroselinum crispum, Phacelia heterophylla, Phacelia tanacetifolia, Phaseolus coccineus, Phaseolus vulgaris, Phleum pratense, Phlox amoena, Phlox carolina, Phlox divaricata, Phlox douglasii, Phlox drummondii, Phlox paniculata, Phlox subulata, Physalis pubescens, Pilosella officinarum, Pisum sativum, Plantago lanceolata, Plantago major, Plantago maritima, Plantago media, Plantago rugelii, Poa annua, Poa pratensis, Poa trivialis, Polygonum aviculare, Polygonum sp., Potentilla anserina, Potentilla indica, Primula Polyanthus hybrids, Primula anisodora, Primula aurantiaca, Primula bulleyana subsp. beesiana, Primula bulleyana, Primula capitata, Primula chionantha, Primula chungensis, Primula cortusoides, Primula denticulata, Primula farinosa, Primula florindae, Primula frondosa, Primula helodoxa, Primula hirsuta, Primula japonica, Primula juliae, Primula latisecta, Primula luteola, Primula megaseifolia, Primula mollis, Primula nana, Primula obconica, Primula polyneura, Primula pulverulenta, Primula rosea, Primula saxatilis, Primula secundiflora, Primula sikkimensis var. sikkimensis, Primula sikkimensis, Primula sinensis, Primula veris, Primula vulgaris, Primula wilsonii, Prunus sp., Puschkinia scilloides, Ranunculus abortivus, Ranunculus acris, Ranunculus arvensis, Ranunculus asiaticus, Ranunculus auricomus, Ranunculus bulbosus, Ranunculus occidentalis, Ranunculus repens, Ranunculus sp., Raphanus raphanistrum, Raphanus sativus, Rheum rhaponticum, Roemeria argemone, Rosa sp., Rumex acetosa, Rumex acetosella, Rumex conglomeratus, Rumex crispus, Rumex obtusifolius, Saccharum officinarum, Saponaria officinalis, Saxifraga cotyledon, Schizanthus retusus, Schizanthus x wisetonensis, Scilla bifolia, Scilla luciliae, Scilla sardensis, Scilla siberica, Scilla sp., Scleranthus annuus, Scorzoneroides pyrenaica, Secale cereale, Senecio vulgaris, Sherardia arvensis, Silene noctiflora, Silene schafta, Simethis planifolia, Sinapis alba, Sinapis arvensis, Solanum carolinense, Solanum demissum, Solanum lycopersicum, Solanum nigrum, Solanum stoloniferum, Solanum tuberosum, Solanum villosum, Solidago canadensis, Sonchus arvensis, Sonchus asper, Sonchus oleraceus, Sonchus sp., Spergula arvensis, Sprekelia formosissima, Stachys arvensis, Stachys palustris, Stellaria media, Sternbergia lutea, Symphyotrichum squamatum, Tagetes patula, Takhtajaniantha tau-saghyz, Tanacetum cinerariifolium, Taraxacum officinale, Taraxacum sp., Thlaspi arvense, Tigridia pavonia, Tigridia sp., Tragopogon porrifolius, Trifolium arvense, Trifolium fragiferum, Trifolium hybridum, Trifolium incarnatum, Trifolium medium, Trifolium pratense, Trifolium repens, Tripleurospermum maritimum, Triticum aestivum, Tuberaria guttata, Tulipa gesneriana, Urceolina sp., Urtica urens, Valerianella dentata, Valerianella locusta, Veronica agrestis, Veronica arvensis, Veronica hederifolia, Veronica peregrina, Veronica serpyllifolia, Veronica spicata, Vicia cracca, Vicia faba, Vicia lens, Vicia sativa, Vicia villosa, Viola arvensis, Viola tricolor, Vitis vinifera, Yucca flaccida, Zea mays

Ditylenchus dipsaci occurs locally in most temperate areas of the world (Europe and the Mediterranean region, North and South America, Northern and Southern Africa, Asia and Oceania) but it does not seem able to establish in tropical regions except at higher altitudes that have a temperate climate. In most countries regulatory measures (e.g. certification schemes) are applied to minimize further spread of D. dipsaci.

EPPO Region: Albania, Algeria, Armenia, Austria, Azerbaijan, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France (mainland), Georgia, Germany, Greece (mainland), Hungary, Ireland, Israel, Italy (mainland, Sicilia), Jordan, Kazakhstan, Kyrgyzstan, Latvia, Lithuania, Malta, Moldova, Morocco, Netherlands, North Macedonia, Norway, Poland, Portugal (mainland, Azores), Romania, Russia (Central Russia, Far East, Southern Russia, Western Siberia), Serbia, Slovakia, Slovenia, Spain (mainland), Sweden, Switzerland, Tunisia, Türkiye, Ukraine, United Kingdom (England, Scotland), Uzbekistan
Africa: Algeria, Kenya, Morocco, Reunion, South Africa, Tunisia
Asia: Bangladesh, China (Gansu, Hebei, Henan, Shandong, Sichuan, Xinjiang), Indonesia (Java), Iran, Iraq, Israel, Japan (Honshu), Jordan, Kazakhstan, Korea, Republic, Kyrgyzstan, Oman, Pakistan, Syria, Uzbekistan, Yemen
North America: Canada (Alberta, British Columbia, Ontario, Prince Edward Island, Québec, Saskatchewan), Mexico, United States of America (Alabama, Arizona, California, Colorado, Hawaii, Idaho, Michigan, Minnesota, Montana, Nevada, New Hampshire, New Mexico, New York, North Carolina, Ohio, Oregon, South Dakota, Utah, Virginia, Washington, Wyoming)
Central America and Caribbean: Costa Rica, Dominican Republic, Haiti
South America: Argentina, Bolivia, Brazil (Minas Gerais, Paraiba, Parana, Rio Grande do Sul, Santa Catarina, Sao Paulo), Chile, Colombia, Ecuador, Paraguay, Peru, Uruguay, Venezuela
Oceania: Australia (New South Wales, Queensland, South Australia, Tasmania, Victoria, Western Australia), New Zealand

It is assumed that D. dipsaci invades seedlings through the stomata of the hypocotyl and cotyledons, and then migrates to the upper part of the hypocotyl, which later develops into the bulb or crown of the plant. D. dipsaci feeds on the cells of the host plant (Hooper, 1971). Injected enzymes in the host cells dissolve the middle lamellae, causing an imbalance in plant hormones, cell hypertrophy, and the formation of intercellular cavities (Duncan and Moens, 2013).

In onion plants at 15°C, the life cycle takes about 20 days. Females lay 200 to 500 eggs each. The reproductive capacity of D. dipsaci varies significantly based on environmental conditions and host tissue (Barbercheck and Duncan, 2004). Griffith et al. (1997) documented a daily production of 0.8 and 3.1 eggs on white clover (Trifolium repens) at temperatures of 10°C and 20°C respectively. Fourth-stage juveniles (dauer larvae) allow nematodes to survive in the absence of a host plant. They tend to aggregate on, or just below, the surface of heavily infested tissue to form clumps of "eelworm wool" and can survive in dry conditions for several years. They may also be attached to the seeds of host plants. Cool, moist conditions favour the infection of young plant tissue by this nematode.

Symptoms

Infected plants commonly exhibit stunted growth, as well as swelling of the hypocotyl and epicotyl (Caubel et al., 1994). Early infections in plants can lead to a low emergence rate and the death of young seedlings (Storelli et al., 2021). Furthermore, D. dipsaci infection can have long-lasting effects, characterized by tissue rotting at harvest or during storage. The damage usually occurs in patches within the fields.

On Allium species

Penetration of onion leaves by D. dipsaci causes leaf deformation and leaf swellings or blister-like areas on the surface. The leaves grow in a disorderly manner, often hang as if wilted and become chlorotic. Young plants can be killed by high infestations. The inner scales of the bulb are usually more severely attacked than the outer scales. As the season advances the bulbs become soft and when cut open show browning of the scales in concentric circles. Conversely, D. dipsaci on garlic does not induce deformations or swellings, but causes leaf yellowing and death (Netscher & Sikora, 1990).

On lucerne

Infected plants decline in patches in the field and damage is more serious in humid climates. The whole plant becomes desiccated and presents symptoms of stunting and swelling at the base of the stem with conspicuous shortened internodes. High levels of infestation can kill plants.

On sugar beet

Penetration of D. dipsaci on sugar beet seedlings results in the swelling of hypocotyls and the distortion of leaves (Storelli et al., 2021). As the growing season progresses, secondary infection by soil-borne pathogens favored by D. dipsaci infestation contribute to crown decomposition in sugar beets (Storelli et al., 2020).

Morphology

Slender transparent worms; adult about 1.2 mm long; head structure moderately developed, spear about 10-12 µm long with distinct basal knobs; lateral fields with four incisures; tail terminus sharply pointed. Post-vulval sac extending about half-way to the anus. See Hooper (1971).

Detection and inspection methods

D. dipsaci can be isolated from soil or plant tissue using Oostenbrink dishes for 24-48 h (EPPO, 2013). Adult and larval individuals can be determined using an optical microscope on the basis of morphological characteristics. When necessary, molecular identification is used.

More details on the detection and identification of D. dipsaci can be found in the EPPO diagnostic protocol (EPPO, 2017).

In international trade, D. dipsaci is liable to be carried on dry seeds and planting material of host plants. In the field, D. dipsaci migration to the soil surface, where infection occurs, is initiated by rainfall or irrigation (Barbercheck and Duncan, 2004). Regular rainfall in spring or autumn just after sowing favours nematode infection.

Economic impact

D. dipsaci is one of the most devastating plant parasitic nematodes, especially in temperate regions. Without control, it can cause complete failure of host crops (e.g. onions, garlic, sugar beet, legumes, strawberries, ornamental plants, especially flower bulbs).

Control

There is no effective direct management method for controlling of D. dipsaci in the field. Its broad host range and its capacity to survive many years without host plants hinders the success of crop rotation strategies (Jones et al., 2013). Successions of crops with high nematode reproduction potential should be avoided.

Nematode-free (certified) seeds and planting material are essential to prevent crop damage by D. dipsaci. Hot-water treatments with different temperature-time combinations, depending on type and state of seed material, are operational and efficient to control D. dipsaci (Gratwick & Southey, 1972). Abamectin B1 and hydrogen cyanide treatment on garlic bulbs prevent nematode transmission through seed material. The use of tolerant or resistant cultivars can also reduce the damage. Cultivars that are resistant (or partially resistant) to D. dipsaci have been reported in clover, alfalfa, faba bean, potatoes, and oat (Storelli, 2022).

Phytosanitary risk

At present, the distribution of the different races throughout the region is patchy and some countries apply official control measures to limit spread. Other countries regard the pest as being a quality pest which can be effectively controlled by production and use of healthy planting material. Without control, D. dipsaci may cause complete failure of host crops within the EPPO region.

The implementation of certification schemes for the production of host plants of D. dipsaci can ensure the production of planting material free from the pest. Restrictions on the movements of plants for planting and seeds of host plants from countries where this nematode occurs may be recommended.

Barbercheck ME & Duncan LW (2004) Abiotic factors. In Gaugler R, Bilgrami AL (Eds.): Nematode behaviour. Wallingford. CABI Publishing, pp. 309–344.

Caubel G, Chatot F & Mousset-Declas C (1994) Résistance variétale du trèfle violet au nématode des tiges Ditylenchus dipsaci. Fourrages 138, 165–173. https://jeb.biologists.org/content/jexbio/199/5/1085.full.pdf [accessed on 22 June 2023].

Eriksson KB (1974) Intraspecific variation in Ditylenchus dipsaci. I. Compatibility tests with races. Nematologica 20, 147-162.

EPPO (2013) EPPO Standards PM 7/119 (1) Nematode extraction. EPPO Bulletin 43, 471-495. https://doi.org/10.1111/epp.12077

EPPO (2017) EPPO Standards PM 7/87 (2) Ditylenchus destructor and Ditylenchus dipsaci. EPPO Bulletin 47, 401-419. https://doi.org/10.1111/epp.12433

Gratwick M & Southey JF (1972) Hot-water treatment of plant material. Bulletin, Ministry of Agriculture, Fisheries and Food 201, 46 pp.

Griffith GS, Cook R & Mizen KA (1997) Ditylenchus dipsaci infestation of Trifolium repens. II. Dynamics of infestation development. Journal of Nematology 29(3), pp. 356–369.

Hooper DJ (1971) Ditylenchus dipsaci. CIH Descriptions of Plant-parasitic Nematodes Set 1, No. 14.

Hooper DJ & Southey JF (1978) Ditylenchus, Anguina and related genera. In: Plant nematology (Ed. by Southey JF) 1, pp. 78-97. Ministry of Agriculture, Fisheries and Food, London, UK.

Jones JT, Haegeman A, Danchin EG, Gaur HS, Helder J, Jones MG, Kikuchi T, Manzanilla-López R, Palomares-Rius JE, Wesemael WM, Perry RN (2013) Top 10 plant-parasitic nematodes in molecular plant pathology. Molecular Plant Pathology 14(9), 946-61. https://doi.org/10.1111/mpp.12057

Netscher C & Sikora A (1990) Nematode parasites of vegetables. In: Plant parasitic nematodes in subtropical and tropical agriculture (Ed. by Luc M, Sikora RA, Bridge J), pp. 237-283. CABI, Wallingford, UK.

Storelli A (2022) Investigation of resistance against Ditylenchus dipsaci on sugar beet. Ph.D. dissertation. Institut für Zuckerrübenforschung Göttingen 56, 138 pp.

Storelli A, Keiser A, Eder R, Jenni S & Kiewnick S (2020) Evaluation of fluopyram for the control of Ditylenchus dipsaci in sugar beet. Journal of Nematology 52, 1-10. https://doi.org/10.21307/jofnem-2020-071

Storelli A, Keiser A, Kiewnick S, Daub M, Mahlein AK, Beyer W & Schumann M (2021) Development of a new in vivo protocol through soil inoculation to investigate sugar beet resistance towards Ditylenchus dipsaci penetration. Nematology 23(6), 685-694. https://doi.org/10.1163/15685411-bja10069

Sturhan D (1969) [The race problem by Ditylenchus dipsaci]. Mitteilungen der Biologischen Bundesanstalt für Land- und Forstwirtschaft 136, 87-98 (in German).

Sturhan D, Hallmann J & Niere B (2008) A nematological jubilee: 150 years. Ditylenchus dipsaci (Kühn, 1857). Nachrichtenblatt des Deutschen Pflanzenschutzdienstes 60(12), 261–266.

Vovlas N, Troccoli A, Palomares-Rius JE, De Luca F, Liébanas G, Landa BB & Subbotin SA (2011) Ditylenchus gigas n. sp. parasitizing broad bean: a new stem nematode singled out from the Ditylenchus dipsaci species complex using a polyphasic approach with molecular phylogeny. Plant Pathology 60, 762-775.

Whitehead AG, Fraser JE & Nichols AJF (1987) Variation in the development of stem nematodes, Ditylenchus dipsaci, in susceptible and resistant crop plants. Annals of Applied Biology 111(2), pp. 373–383. https://doi.org/10.1111/j.1744-7348.1987.tb01465.x

This datasheet was extensively revised in 2023 by Alan Storelli, Agroscope, Switzerland. His valuable contribution is gratefully acknowledged.

EPPO (2024) Ditylenchus dipsaci. EPPO datasheets on pests recommended for regulation. https://gd.eppo.int (accessed 2024-11-23)

This datasheet was first published in 1992 in 'Quarantine Pests for Europe' and revised in the second edition of the book in 1997, as well as in 2023. It is now maintained in an electronic format in the EPPO Global Database. The sections on 'Identity', ‘Hosts’, and 'Geographical distribution' are automatically updated from the database. For other sections, the date of last revision is indicated on the right.

CABI/EPPO (1992/1997) Quarantine Pests for Europe (1st and 2nd edition). CABI, Wallingford (GB).