New data on quarantine pests and pests of the EPPO Alert List
By searching through the literature, the EPPO Secretariat has extracted the following new data concerning quarantine pests and pests included (or formerly included) on the EPPO Alert List, and indicated in bold the situation of the pest concerned using the terms of ISPM no. 8.
- New records
In Pakistan, potato (Solanum tuberosum) plants showing blackleg symptoms were observed in January 2017 in the Okara district (Punjab). Laboratory studies confirmed the presence of Dickeya dianthicola (EPPO A2 List) in the collected stem samples (Sarfraz et al., 2018). Present, no details.
In Ethiopia, Glycaspis brimblecombei (Hemiptera: Aphalaridae – formerly EPPO Alert List) was found for the first time in October 2018 in Ginchi and Ambo towns on Eucalyptus camaldulensis. Subsequently, another infestation was observed in Gedo on E. camaldulensis. During these studies, heavy infestations were observed along roadside plantations of E. camaldulensis (Yirgu and Anjulo, 2019).
In Slovenia, bleeding cankers were noticed in December 2016 on horse chestnut trees (Aesculus hippocastanum) planted along two streets in Ljubljana. Laboratory studies confirmed the presence of Pseudomonas syringae pv. aesculi (formerly EPPO Alert List) in diseased trees. The origin of this outbreak is unknown, but it is suspected that the bacterium was introduced with imported planting material. It is added that symptoms of the disease were first observed in 2014 on young trees in Ljubljana. Some trees later died and were cut down. In 2017, bleeding cankers were observed on old trees located in the vicinity of these young trees. To avoid any further spread of the disease, disinfection of tools and destruction of infected plant material were recommended (Pirc et al., 2018).
In Greece, Tomato leaf curl New Delhi virus (ToLCNDV, EPPO Alert List) was found in one location in a cucurbit crop in October 2018 in the region of Elias. Official surveys are being carried out to determine the extent of the infestation (Rodiotakis and Pappi, 2018).
In Iran, Tomato leaf curl New Delhi virus (ToLCNDV, EPPO Alert List) was found during surveys performed in 2012-2014 in field-grown vegetables. ToLCNDV was found in a melon crop in Khuzestan province (South-West Iran). The authors report previous findings in solanaceous crops in South-East Iran (Yazdani-Khameneh et al., 2016).
- Detailed records
In Karnataka (India), Leucinodes orbonalis (EPPO A1 List) has recently become a destructive pest of potato (Solanum tuberosum), causing heavy losses. Up to now it was mainly recorded as a pest of eggplant (Solanum melongena) (Natikar and Balikai, 2018).
In the USA, Meloidogyne enterolobii (EPPO A2 List) was first reported in Florida and more recently in North Carolina infecting root-knot nematode resistant varieties of cotton (Gossypium spp.) and soybean (Glycine max). During a survey for root-knot nematodes conducted in South Carolina, M. enterolobii was detected in a soil sample which had been collected in February 2018 from a field in Darlington county. This field had been grown with soybean and sweet potato (in rotation) for several years. Further studies also detected M. enterolobii in symptomatic roots of a sweet potato cultivar resistant to root-knot nematodes (Ipomoea batatas cv. Covington). Greenhouse tests confirmed that M. enterolobii was highly virulent on this sweet potato cultivar (Rutter et al., 2019).
In the USA, symptoms of a phytoplasma disease were observed during autumn 2017 on ornamental palm trees (3 Phoenix sylvestris and 3 Trachycarpus fortunei) planted in a residential landscape in Baton Rouge, Louisiana. Laboratory analysis of trunk shavings collected from diseased palm trees revealed the presence of lethal yellowing-associated phytoplasma (subgroup 16SrIV-A) related strains. Affected P. sylvestris showed necrosis of fronds in the lower one-third of the canopy and T. fortunei had dead spear leaves with lower fronds drooping which went either chlorotic or necrotic. In the USA, this is the first time that palm lethal yellowing phytoplasma (EPPO A1 List) is reported outside Florida (Ferguson and Singh, 2018).
In Tunisia, Tomato leaf curl New Delhi virus (ToLCNDV, EPPO Alert List) was found in tomato crops in heated plastic tunnels in the South of Tunisia. It had been found in cucurbits in 2015 (Zammouri et al., 2017).
- Host plants
In Ecuador, Clavibacter michiganensis subsp. michiganensis (EPPO A2 List) is causing bacterial canker of naranjilla or lulo (common names for both Solanum quitoense and Solanum pectinatum). The disease was first identified in 2008 and can destroy naranjilla plants (Bolanos-Carriel et al., 2018).
In Mexico, rust symptoms were observed on Crataegus gracilior (tejocote) orchards in the state of Puebla. Laboratory studies confirmed the presence of Gymnosporangium globosum (EPPO A1 List) in diseased samples. It is noted that G. globosum had previously been reported on Crataegus mexicana (also called tejocote) in Mexico (Alvarado-Rosales et al., 2018).
In USA, Melampsora medusae (EPPO A2 List) was detected for the first time on cultivated Populus mexicana subsp. dimorpha trees in Gainesville, Florida. It is noted that disease symptoms began in late summer and progressed from chlorotic leaf spots to necrotic leaf spots; rust pustules then formed and were followed by early defoliation. It is noted that M. medusae had been reported previously on P. mexicana in Mexico (Loyd and Smith, 2018).
In Lithuania, during a survey conducted in 2017 in the district of Kaunas, phytoplasma-like symptoms were observed in a private garden on Forsythia suspensa (leaf reddening), Spiraea vanhouttei (decline) and Viburnum lantana (witches’ broom). Laboratory studies confirmed the presence of ‘Candidatus Phytoplasma mali’ (EPPO A2 List) in these symptomatic plants. Further studies are needed to determine the possible role of these ornamental species in the epidemiology of apple proliferation disease (Abraitienë et al., 2018).
In tomato production, bumblebees Bombus terrestris (Hymenoptera: Apidae) are used extensively for pollination purposes. A study conducted in Israel showed that Tomato brown rugose fruit virus (Tobamovirus, ToBRFV - EPPO Alert List) can be carried by bumblebees and transmitted to healthy plants during pollination (mechanically). Placing a bumblebee hive collected from a ToBRFV contaminated greenhouse, in a glass- or net-house containing only uninfected healthy tomato plants, spreads ToBRFV disease. This should be considered when taking measures to prevent spread or to eradicate this virus (Levitzky et al., 2019).
- New pests and taxonomy
Taxonomic studies have shown that Botryosphaeria berengeriana f. sp. piricola (EU Annexes) should be considered as a separate and distinct species called Botryosphaeria kuwatsukai sp. nov. During these studies, it was also stressed that the main causal agents for apple ring rot in China and Japan are Botryosphaeria dothidea and B. kuwatsukai. As B. kuwatsukai has been confused with B. dothidea over the years, this introduces uncertainty about the geographical distributions and host ranges of both species (Xu et al., 2015).
Abraitienë A, Bevilacqua A, Scarafoni A, Quaglino F (2018) First report of Forsythia suspensa, Spiraea vanhouttei and Viburnum lantana as new natural plant hosts of ‘Candidatus Phytoplasma mali’ the causal agent of apple proliferation disease in Lithuania. Plant Disease 102(10), p 2026.
Alvarado-Rosales D, Ayala-Escobar V, Téliz-Ortiz D, Nieto-López EH, Nieto-Angel R, Tovar-Pedraza JM (2018) First report of Gymnosporangium globosum on Crataegus gracilior in Mexico. Plant Disease 102(10), p 2034.
Bolanos-Carriel C, Gallegos P, Ochoa JB, Insuasti M, Bonilla V & Evans MH, Alvarez J, Ramirez D, Leon-Reyes A (2019). Bacterial canker caused by Clavibacter michiganensis subsp. michiganensis in naranjilla. Biotecnología Vegetal 17(4), 221–227.
Ferguson MH, Singh R (2018) First report of lethal yellowing associated with phytoplasma subgroup 16SrIV-A on silver date palm and Chinese windmill palm in Louisiana. Plant Disease 102(10), p 2028.
Rodiotakis E, Pappi P (2018) Tomato leaf curl New Delhi virus, ToLCNDV https://geotee.gr/lnkFiles/20181120133356_4.pdf (in Greek).
Levitzky N, Smith E, Lachman O, Luria N, Mizrahi Y, Bakelman H, Sela N, Laskar O, Milrot E, Dombravsky A (2019) The bumblebee Bombus terrestris carries a primary inoculum of Tomato brown rugose fruit virus contributing to disease spread in tomatoes. PLoS ONE 14(1): e0210871. https://doi.org/10.1371/journal.pone.0210871.
Lloyd AL, Smith JA (2018) First report of poplar leaf rust caused by Melampsora medusae on Populus mexicana in the United States. Plant Disease 102(10), 2031-2033.
Natikar PK & Balikai RA (2018) Status of insect pests of potato and their natural enemies 21(2), 1163–1172.
Pirc M, Dreo T, Jurc D (2018) First report of Pseudomonas syringae pv. aesculi as the causal agent of bleeding canker of horse chestnut in Slovenia. Plant Disease 102(10), p 2025.
Rutter WB, Skantar AM, Handoo ZA, Mueller JD, Aultman SP, Agudelo P (2019) Meloidogyne enterolobii found infecting root-knot nematode resistant sweetpotato in South Carolina, United States. Plant Disease (early view). https://doi.org/10.1094/PDIS-08-18-1388-PDN
Sarfraz S, Riaz K, Oulghazi S, Cigna J, Alam MW, Dessaux Y, Faure D (2018) First report of Dickeya dianthicola causing blackleg disease on potato plant in Pakistan. Plant Disease 102(10), 2027-2028.
Xu C, Wang CS, Ju LL, Zhang R, Biggs AR, Tanaka E, Li BZ, Sun GY (2015) Multiple locus genealogies and phenotypic characters reappraise the causal agent of apple ring rot in China. Fungal Diversity 71, 215-231.
Yazdani-Khameneh S, Aboutorabi S, Shoori M, Aghazadeh A, Jahanshahi P, Golnaraghi A, Maleki M (2016) Natural Occurrence of Tomato leaf curl New Delhi virus in Iranian Cucurbit Crops. The Plant Pathology Journal 32(3), 201-208 http://dx.doi.org/10.5423/PPJ.OA.10.2015.0210
Yirgu A, Anjulo A (2019) First record of Glycaspis brimblecombei Moore (Hem.: Psyllidae) on Eucalyptus camaldulensis in Ethiopia. Phytoparasitica 47(1), 67-70.
Zammouri S, Zaagueri T, Eddouzi J, Belkhadhi MS, Hajlaoui MR and Mnari-Hattab M (2017) First report of Tomato leaf curl New Delhi virus on tomato crop in Tunisia. Journal of Plant Pathology 99(3), 799-818. http://dx.doi.org/10.4454/jpp.v99i3.3975