EPPO Global Database

EPPO Reporting Service no. 04 - 2000 Num. article: 2000/061

Additions to the EPPO Alert List

At the last EPPO Panel meeting on Phytosanitary Measures in 2000-01, several proposals for addition to the EPPO Alert List were suggested by United Kingdom and documented. As a result, the following 6 insect species and fungi have been added to the list.

Aleurodicus dispersus (Homoptera: Aleyrodidae) - Spiralling whitefly
Why        The NPPO of UK suggested that Aleurodicus dispersus could be added to the EPPO Alert List.
Where        A. dispersus originates from the tropical Americas. It occurs in many countries in Central and South America and in the Caribbean. It has also occurred in the Canary Islands since 1963. More recently, it has been reported from Asia and Africa.
       EPPO region: Spain (Canary Islands: Tenerife, Gran Canaria, Lanzarote) ; Asia: Bangladesh, Brunei Darussalam, India (Karnataka, Kerala, Tamil Nadu), Indonesia (Java, Sumatra), Laos, Malaysia (peninsular, Sabah, Sarawak), Maldives, Myanmar, Philippines, Singapore, Sri Lanka, Taiwan, Thailand, Vietnam ; Africa: Benin, Congo, Nigeria, Togo ; North America: USA (Florida, Hawaii) ; South America: Brazil (Bahia), Peru ; Caribbean and Central America: Bahamas, Barbados, Costa Rica, Cuba, Dominica, Dominican Republic, Ecuador, Haiti, Martinique, Panama, Puerto Rico ; Oceania: American Samoa, Australia (few cases found in Queensland, under quarantine), Cook Islands, Fiji, Kiribati, Guam, Micronesia, Nauru, Northern Mariana Islands, Papua New Guinea
On which plants        A. dispersus is a highly polyphagous species. Its wide host range includes many vegetable, ornamental and fruit crops, as well as numerous trees and shrubs. Among its host plants, the following crops can be mentioned: Capsicum, Citrus, Cocos nucifera (coconut), Euphorbia pulcherrima (poinsettia), Glycine max (soybean), Hibiscus, Lycopersicon esculentum (tomato), Mangifera indica (mango), Musa (banana), Persea americana (avocado), Prunus spp., Solanum melongena (aubergine), etc.
Damage        Immature and adult stages of A. dispersus cause direct feeding damage by sucking plant sap, which can cause premature leaf fall. Indirect damage is due to the heavy production of honeydew and white, waxy material produced by the insect. Sooty mould develops on honeydew and decreases phytosynthesis activity. Plants are also disfigured and may be unmarketable. In places where is occurs, A. dispersus is generally considered as a serious pest, causing crop losses. Virus transmission is apparently not known.
Dissemination        Natural dispersion can be ensured by flying adults. Over long distances, the pest has already showed its potential for spreading, being introduced into many different parts of the world. Movements of infested plants or fruits can ensure long distance dissemination.
Pathway        Plants for planting, vegetables and fruits, cut flowers? from countries where A. dispersus occurs.
Possible risks        A. dispersus is a pest of tropical and sub-tropical crops, and it appears unlikely that it could establish outdoors in most parts of the EPPO region. However, it may present a risk for the warmest parts of southern Europe, where many of its host plants are grown (citrus, avocado, palms, tomato, aubergine etc.). It may also present a risk for ornamentals or vegetable crops grown under glasshouse conditions. Chemical and biological control (release of parasitoids) methods are available, but the pest is apparently difficult to control.
Source(s)        NPPO of UK, 2000-01, Summary PRA by Dr A. MacLeod.
       Anonymous (2000) Management of spiralling whiteflies. SPC Agricultural News, 8(2), p 12.
       CABI (1993) Distribution maps of pests, Aleurodicus dispersus, Map no; 476, CABI, Wallingford, UK.
       CABI Crop Protection Compendium, Global Module, 1999 edition. CABI, Wallingford, UK.
       D'Almeida, Y.A.; Lys, J.A.; Neuenschwander, P.; Ajuonu, O. (1998) Impact of two accidentally introduced Encarsia species (Hymenoptera: Aphelinidae) and other biotic and abiotic factors on the spiralling whitefly Aleurodicus dispersus (Russell) (Homoptera: Aleyrodidae), in Benin, West Africa. Biocontrol Science and Technology, 8(1), 163-173. (abst.)
       Kiyindou, A.; Adoumbaye, I.P.; Mizere, D.; Moussa, J.B. (1999) Influence de la plante hôte sur le developpement et la reproduction de l'aleurode Aleurodicus dispersus Russell (Hom.: Aleyrodidae) en République du Congo. Fruits, 54(2), 115-122. (abst.)
       Mani, M.; Krishnamoorthy, A. (1996) Spiralling whitefly and its natural enemies on guava in Karnataka. Insect Environment, 2(1), 12-13. (abst.)
       Mani, M.; Krishnamoorthy, A. (1997) Discovery of Australian ladybird beetle (Cryptolaemus montrouzieri) on spiralling whitefly (Aleurodicus dispersus) in India. Insect Environment, 3(1), 5-6. (abst.)
       Shah-Alam; Islam, M.N.; Alam, M.Z.; Islam, M.S. (1997) Identification of the whitefly in guava, its spatial distribution and host susceptibility. Bangladesh Journal of Entomology, 7(1-2), 67-73. (abst.)
       DPI Note (Department of Primary Industries Queensland) - Spiralling whitefly: threat to Australia by Trevor Lambkin
EPPO RS 2000/061
Panel review date        -        Entry date 2000-04

Chrysodeixis eriosoma (Lepidoptera: Noctuidae) - Green semi-looper
Why        The NPPO of UK suggested that Chrysodeixis eriosoma (synonyms: Plusia eriosoma, Phytometra eriosoma) could be added to the EPPO Alert List. This pest has been intercepted by UK on Tibouchina cuttings imported from Australia.
Where        The species occurs throughout the tropical and subtropical regions of eastern Asia and the Pacific islands as well as in Australia and New Zealand.
       Asia: Brunei Darussalam, Cambodia, China (Fujian, Guangdong), India (Assam, Delhi, Maharashtra, Tamil Nadu, Uttar Pradesh), Indonesia, Japan, Korea, Malaysia, Myanmar, Philippines, Sri Lanka, Thailand, Vietnam. Bin-Chen Zhang mentions its presence in Russia and Turkmenistan ; North America: USA (Hawaii) ; Oceania: Australia (New South Wales, Northern Territory, Queensland, Tasmania), Fiji, New Zealand, Papua New Guinea, Tonga.
On which plants        Larvae are highly polyphagous and feed on foliage and fruit of many field and vegetable crops, ornamentals and weeds. Its wide host range includes: chick peas (Cicer arietinum), lucerne (Medicago sativa), maize (Zea mays), potato (Solanum tuberosum), sunflower (Helianthus annuus), soybean (Glycine max), tobacco (Nicotiana tabacum) - beans (Phaseolus vulgaris,) cabbages (Brassica oleracea), cucurbits (Curcurbita pepo, Cucumis sativus), peas (Pisum sativum), tomato (Lycopersicon esculentum) - many ornamentals, e.g Coleus, chrysanthemums, dahlia, freesia, pelargonium, Tibouchina.
Damage        Eggs are laid on the underside of leaves. Damage is done by the larvae. They feed on the underside of the leaf, making windows between the veins (young larvae leave the upper leaf cuticule and later instars make ragged holes). On tomato, larvae can chew into green fruits and can excavate legume pods. Adults feed on flower nectar. In heavy infestations, plants can be completely defoliated. Caterpillars spin a silken cocoon attached to the underside of a leaf, and the brown pupa forms within this structure. In Australia, C. eriosoma is considered as a sporadic pest of horticultural crops. In New Zealand, its occurrence is sporadic south of Christchurch, but is common from Blenheim (latitude 42°S) northwards in all horticultural areas. Data is lacking on actual crop losses, as it seems that defoliation does not always induce yield losses (although situation may be different when fruits or ornamentals are attacked).
Dissemination        Adults are good flyers. Eggs, larvae and pupae of C. eriosoma can all be carried on leaves of host plants.
Note        C. eriosoma is closely related to the Palaearctic species C. chalcites which occurs in several European countries. The relationships and status of these two species still need to be clarified. C. chalcites is a pest of moderate importance in Europe.
Pathway        Plants for planting, fruits and vegetables, cut flowers and branches of host plants from countries where C. eriosoma occurs.
Possible risks        Many C. eriosoma host plants are widely grown in the EPPO region and are major crops. Climate matching studies done in UK showed that it could probably establish outdoors in many parts of the EPPO region. C. eriosoma could also be a threat to glasshouse crops (e.g. cucumbers, tomatoes and many ornamentals). Control methods (chemical and biological) are available.
Source(s)        NPPO of UK, 2000-01, Summary PRA by Dr A. MacLeod
       CABI Crop Protection Compendium, Global Module, 1999 edition. CABI, Wallingford, UK.
       Hely, P.C.; Pasfield, G.; Gellatley, J.G. (eds) (1982) Insect pests of fruit and vegetables in NSW, Department of Agriculture New South Wales, Inkata Press, Melbourne, Sidney and London, 312 pp.
       Bin-Cheng Zhang (1994) Index of economically important Lepidoptera. CABI, Wallingford, UK, 599 pp.
       HortFACT, Silver Y moth life cycle: http:/:www.hortnet.co.nz/publications/hortfacts/hf401020.htm
       Crop knowledge Master. Chrysodeixis eriosoma: http://www.extento.hawaii.edu/Kbase/crop/Type/chrysode.htm
       Chrysodeixis eriosoma: http://www-staff.mcs.uts.edu.au/~don/larvae/noct/eriosom.html
EPPO RS 2000/061
Panel review date        -        Entry date 2000-04

Neotoxoptera formosana (Homoptera: Aphididae) -  Onion aphid
Why        The NPPO of UK suggested that Neotoxoptera formosana could be added to the EPPO Alert List. This pest has been found in September 1999, on a stock of Welsh onions (A. fistulosum) growing in a plastic tub in the Model Vegetable Garden at RHS Wisley, Surrey, UK. A nearby tub of garlic (A. sativum) and Chinese chives (A. tuberosum) were also lightly infested. Both tubs were destroyed. Other potential hosts in the vegetable garden were inspected: A. fistulosum cv. Saville and A. porrum were found infested.
Where        Asia: China, Japan, Korea, Taiwan ; North America: USA (Hawaii); South America: Brazil, Chile (these are apparently rather recent findings made in the 1990s) ; Oceania: Australia (reported as now widespread, including Tasmania, but was not recorded there before 1974), New Zealand. It was also reported that N. formosana was found in Finland in 1994 on onions imported from the Netherlands.
On which plants        Allium species (A. bakeri, A. ascalonicum, A. cepa, A. cernuum, A. chinense, A. fistulosum, A. neopolitanum, A. porrum, A. sativum, A. schoenoprasum). Reported as a pest of beans (without further details) in Hawaii.
Damage        Feeding damage on leaves. In Japan, it was shown that N. formosana can transmit garlic latent carlavirus. In Australia, serious outbreaks have been reported on onions in storage, particularly on those just beginning to sprout. More data is needed on the biology and damage caused by this pest.
Pathway        Plants for planting, bulbs, vegetables from countries where N. formosana occurs.
Possible risks        Allium crops are widely grown in the EPPO region. The isolated findings in Europe, and its presence in Tasmania, may suggests that N. formosana could survive in the European and Mediterranean region, but biological and ecological data is lacking. It appears also that this pest has a potential for spread over long distances (e.g. relatively recent records in South America and in Europe). Data is lacking on its economic importance to Allium crops, and the possibilities for control.
Source(s)        NPPO of UK, 2000-01, draft data sheet by R. Cannon & R. Hammon.
       Sako, I.; Taniguchi, T.; Osaki, T.; Inouye, T. (1990) Transmission and translocation of garlic latent virus in rakkyo (Allium chinense G. Don). Proceedings of the Kansai Plant Protection Society. No. 32, 21-27 (abst.).
       Stary, P.; Rodriguez, F.; Remaudiere, G. (1994) [Plant-aphid-parasitoid association (Hom., Aphidoidea; Hym., Aphidiidae) in central area of Chile.] Agricultura Tecnica Santiago, 54(1), 46-53. (abst.)
       Bibliographic references. Afideos do Brasil e suas plantas hospedeiras (lista preliminar). Carlos R. Souza-Silva & Albano Ilharco. EDUFSCar, 85 pp. 1995. (abstract of contents) http://www.ciagri.usp.br/~seb/info3.htm
EPPO RS 2000/061
Panel review date        -        Entry date 2000-04

Trialeurodes ricini (Homoptera: Aleyrodidae) - Castor whitefly
Why        The NPPO of UK suggested that Trialeurodes ricini (synonym T. rara) could be added to the EPPO Alert List. This pest was recently introduced into Egypt. It was found there for the first time in September 1997 on Ricinus communis in Qalyubiya Governorate, and rapidly became widespread. It has been intercepted twice by UK on unspecified leaves from Cameroon and Nigeria (possibly Amaranthus leaves).
Where        EPPO region: Egypt, Israel ; Asia: Brunei Darussalam, India (Gujarat, Tamil Nadu, Uttar Pradesh), Iran, Iraq, Malaysia (peninsular), Saudi Arabia, Thailand ; Africa: Cameroon (unconfirmed), Chad, Egypt, Nigeria, Sudan
On which plants        T. ricini is a polyphagous species. Its preferred host are: Ricinus communis (castor bean), Dolichos lablab, Gossypium hirsutum (cotton). But it can also feed on Cucurbita maxima (pumkin), Ipomoea batatas (sweet potato), Solanum melongena (aubergine), Phaseolus vulgaris (bean), Lycopersicon esculentum (tomato), Solanum tuberosum (potato), Cucurbita pepo (melon), Cumumis sativa (cucumber), etc.
Damage        Adults and immature stages of T. ricini suck sap from the lower surfaces of the leaves which then wither and turn brown. Secretion of honeydew results in growth of sooty moulds. In Egypt, T. ricini has been reported as a vector of tomato yellow leaf curl begomovirus.
Dissemination        Natural dispersion can be ensured by flying adults. Movements of infested plants or fruits can ensure long distance dissemination.
Pathway        Infected plants for planting, vegetables and fruits from countries where T. ricini occurs.
Possible risks        T. ricini is a tropical and sub-tropical pest (most favourable temperatures appears to be 25 to 30 °C), and it appears unlikely that it could establish outdoors in most parts of the EPPO region. However, it may present a risk for southern Europe, where many of its host plants are grown (cotton, cucurbits, tomato, aubergine, etc.). It may also present a risk for vegetable crops grown under glasshouse conditions. An additional concern is the transmission of tomato yellow leaf curl begomovirus. Chemical and biological control (release of parasitoids, e.g. Encarsia formosa) methods are available, but the pest is difficult to control.
Source(s)        NPPO of UK, 2000-01, Summary PRA by Dr A. MacLeod
       Abd-Rabou, S. (1999) New records of whiteflies in Egypt. Egyptian Journal of Agricultural Research, 77(3), 1143-1145.
       David, B.V.; Radha, N.V.; Seshu, K.A. (1973) Influence of weather factors on the population of the castor Aleyrodid Trialeurodes rara Singh. Madras Agricultural Journal, 60(7), 496-499. (abst.)
       Idriss, M.; Abdallah, N.; Aref, N.; Haridy, G.; Madkour, M. (1997) Biotypes of the castor bean whitefly Trialeurodes ricini (Misra) (Hom., Aleyrodidae) in Egypt: biochemical characterization and efficiency of geminivirus transmission. Journal of Applied Entomology, 121(9-10), 501-509. (abst.)
       Lourens, J.H.; Brader, L.; Van der Laan, P.A. (1972) Contribution à l'étude d'une 'mosaïque' du cotonnier au Tchad; distribution dans un champ; Aleurodidae communs; essais de transmission de cotonnier à cotonnier par les Aleurodidae. Coton et Fibres Tropicales, 27(2), 225-230.(abst)
       Martin, J.H. (1987) An identification guide to common whitefly pest species of the world (Homoptera: Aleyrodidae). Tropical Pest Management, 33(4), 298-322.
       Shishehbor, P.; Brennan, P.A. (1995) Parasitism of Trialeurodes ricini by Encarsia formosa: level of parasitism, development time and mortality on different host plants. Entomophaga. 1995, 40(3-4), 299-305.
       Srivastava, A.S.; Srivastava, J.L.; Tripathi, R.A. (1972) Incidence of pests on castor. Labdev Journal of Science and Technology, 10(B1), 47-48. (abst.)
       Vora, V.J.; Bharodia, R.K.; Kapadia, M.N. (1984)  Pests of oilseed crops and their control - castor. Pesticides, 18(11), 3-5.
EPPO RS 2000/061
Panel review date        -        Entry date 2000-04

Thrips imaginis (Thysanoptera: Thripidae) - Plague thrips
Why        The NPPO of UK suggested that Thrips imaginis could be added to the EPPO Alert List. It has been intercepted by UK on cut flowers (Grevillea) imported from Australia.
Where        Oceania: Australia (all states), Fiji, New Caledonia, New Zealand, Papua New Guinea and some Pacific islands.
On which plants        Polyphagous pest. Its wide host range includes ornamentals (e.g. Dianthus, Gerbera, Rosa, Tagetes), fruit crops (apple, pear, citrus, peach, plum, strawberry, Rubus, grapevine), field crops (e.g. lucerne, cotton), pastures and grasses.
Damage        T. imaginis feeds mainly on flowers but also on young foliage by rasping the plant tissue and sucking cell contents. Adult females damage the plant tissue when depositing their eggs. When thrips feed on flowers, the anthers, petals and pistil turn brown and shrivel, then fall prematurely. This prevents fruit set in fruit crops or decrease the plant value in floral crops. In Australia, T. imaginis is considered as a pest of apple orchards as it damages apple flowers leading to crop losses. In New Zealand, populations do not reach sufficient numbers to cause economic problems. T. imaginis is not a vector of tomato spotted wilt tospovirus.
Dissemination        Adult thrips can fly over limited distances but are carried by the wind. As T. imaginis overwinters in the soil (pre-pupal and pupal stages), it can be disseminated by infested soil. Movement of infected plants or plant parts can disseminate this pest.
Pathway        Plants for planting, cut flowers, soil from countries where T. imaginis occurs.
Possible risks        In climate-matching studies done in UK, it appears unlikely that T. imaginis could survive outdoors in Northern Europe, but could do so in southern Europe (the example taken was Barcelona, Spain). There are no records of T. imaginis on glasshouse crops, but it might be able to survive under these conditions in the EPPO region. Many of its host plants are widely grown and of economic importance in the EPPO region. Chemical control can be used but thrips are generally not easily eliminated (no data on biological control).
Source(s)        NPPO of UK 2000-01, Summary PRA by Dr A. MacLeod.
       Hely, P.C.; Pasfield, G.; Gellatley, J.G. (eds) (1982) Insect pests of fruit and vegetables in NSW, Department of Agriculture New South Wales, Inkata Press, Melbourne, Sidney and London, 312 pp.
       Palmer, J.M.; Mound, L.A.; du Haume, G.J. (1989) CIE Guide to insects of importance to man. 2. Thysanoptera edited by C.R. Betts. CABI, Wallingford, UK, 73 pp.
       Plague thrips. http://www.space.net.au/~grnlife/gsplaguethrip.htm
EPPO RS 2000/061
Panel review date        -        Entry date 2000-04

Thrips parvispinus (Thysanoptera: Thripidae) - A south-east Asian thrips
Why        The NPPO of UK suggested that Thrips parvispinus could be added to the EPPO Alert List. This Asian species was recently reported as damaging Gardenia plants growing in 2 glasshouses near Volos, in Greece. Intercepted (as T. taiwanus) by the Netherlands in 1996 on a consignment of Gardenia cut flowers from Indonesia.
Where        EPPO region: Greece (isolated findings) ; Asia: Indonesia (Java), Malaysia, Singapore, Taiwan, Thailand ; Oceania: Australia, Solomon Islands.
On which plants        T. parvispinus is considered as a polyphagous species. It is reported as a major pest of Capsicum in Java, and of vegetable crops in Thailand. In Malaysia, it is a pest of papaya.
Damage        Direct feeding damage. In Malaysia, feeding damage on papaya is associated with secondary attacks by the saprophytic fungus Cladosporium oxysporum (causing bunchy and malformed top of papaya). Extensive leaf damage was observed on Gardenia plants in Greece. Recorded as a vector of tobacco streak ilarvirus in transmission studies from infected tomato pollen to seedlings of Chenopodium amaranticolor.
Note        Taxonomy may need further clarification, but it is now considered that T. taiwanus and Isoneurothrips jenseni are synonyms of T. parvispinus, and that T. compressicornis is a distinct species.
Pathway        Plants for planting, cut flowers and branches from countries where T.parvispinus occurs.
Possible risks        T. parvispinus can be spread by movement of infested plants (at least two examples on imported Gardenia plants). Data is lacking on its biology and potential of establishment in the EPPO region. But as a tropical and polyphagous species, it could present a risk to protected ornamental and vegetable crops. Chemical control is possible, but is probably difficult as for many other thrips species.
Source(s)        NPPO of UK, 2000-01.
       Bansiddhi, K.; Poonchaisri, S. (1991) Thrips of vegetables and other commercially important crops in Thailand. AVRDC Publication. No. 91-342 (abst.).
       Klose, M.J.; Sdoodee, R.; Teakle, D.S.; Milne, J.R.; Greber, R.S.; Walter, G.H. (1996) Transmission of three strains of tobacco streak ilarvirus by different thrips species using virus-infected pollen. Journal of Phytopathology, 144(6), 281-284.
       Lim, W.H. (1989) Bunchy and malformed top of papaya cv. Eksotika caused by Thrips parvispinus and Cladosporium oxysporum. MARDI Research Journal, 17(2), 200-207 (abst).
       Vos, J.G.M.; Frinking, H.D. (1998) Pests and diseases of hot pepper (Capsicum spp.) in tropical lowlands of Java, Indonesia. Journal of Plant Protection in the Tropics, 11(1), 53-71.
EPPO RS 2000/061
Panel review date        -        Entry date 2000-04

Stegophora ulmea (Fungi: Ascomycete: Diaporthales) - Elm black spot
Why        The NPPO of UK suggested that Stegophora ulmea could be added to the EPPO Alert List. In 1999, UK has intercepted two consignments of bonsai elms imported from China infected by this fungus.
Where        S. ulmea is considered as native and widespread in North America: Canada (presumably), USA (reported from warm areas such as California, to cooler areas like Wisconsin). An old record in Romania appears in the literature, but the presence of the disease is not confirmed. The two recent interceptions of bonsais plants from China suggest that the fungus is probably present there.
On which plants        Elms (Ulmus spp.): U. alata, U. americana, U. carpinifolia, U. crassifolia, U. glabra, U. hollandica, U. japonica, U. laciniata, U. laevis, U. parvifolia, U. procera, U. pumila, U. serotina, U. thomasii, U. rubra. Zelkova is also mentioned as a host. Most elm species are susceptible to black spot, although there is large variation in disease severity among cultivars of the same species. Many new hybrid cultivars resistant to Dutch elm disease are descended from parents which are particularly susceptible to S. ulmea.
Damage        Black leaf spots which can be surrounded by a white to light yellow halo, lesions may girdle petioles. Black spot is generally considered to be a minor problem on mature elms, but it can cause significant defoliation and twig dieback on susceptible elm cultivars in nurseries. In the field, the disease is rarely fatal and in dry conditions, even severely blighted parts can recover.
Dissemination        S. ulmea overwinters in dead leaves and in dormant buds. In spring, ascospores infect young leaves and stems. Secondary infection is ensured by macroconidia which are released from acervuli and spread by rain splash. Over long distances, the fungus can be spread by infected plants either actively growing or in dormant stage.
Note        Stegophora ulmea is the accepted name of the teleomorph (synonym: Gnomonia ulmea). The anamorphic forms of conidia which develop in acervuli are macroconidia: Gloeosporium ulmicolum and microconidia: Cylindrosporella ulmea (synonyms: Asteroma ulmeum, Gloeosporium ulmeum).
Pathway        Plants for planting of Ulmus and Zelkova (even dormant), bonsais, cut branches from countries where S. ulmea occurs.
Possible risks        S. ulmea could present a risk for nurseries producing elms or Zelkova plants. For amenity or forest elm trees, the risk is more limited as the disease is apparently not very damaging to mature trees.
Source(s)        NPPO of UK 2000-01, Summary PRA and Data Sheet by J. Cooper and C. Sansford.
       Black spot of elm trees. Research and Extension Kansas State University
       Department of Agriculture and Marketing (Nova Scotia, CA) Abstract of trials
EPPO RS 2000/061
Panel review date        -        Entry date 2000-04