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 the Republic of Korea, 25 grapevine samples exhibiting foliar symptoms of mottling, yellowing, reddening, and malformation, and 5 asymptomatic samples were collected in July 2014 in Suwon and Gyeongsan, respectively. Molecular tests confirmed the presence of Grapevine red blotch-associated virus (Geminiviridae, GRBaV - EPPO Alert List) in 2 samples which showed leaf mottling and yellowing. This is the first time that GRBaV is reported from the Republic of Korea. So far, GRBaV had only been reported from Canada and the USA (Lim et al., 2016). Present, only in some areas.
Little cherry virus 1 (Velarivirus, LChV-1 – EU Annexes) is reported for the first time from Spain. LChV-1 was detected in symptomatic samples of sweet cherry (Prunus avium) which had been collected in 2012 in Valle del Jerte (Cáceres province - Extremadura) and Ponferrada (León province - Castilla y León). It is noted that the prevalence of LChV-1 in the cherry-growing areas of Spain remains to be determined (Ruiz-García et al., 2016). Present, only in some areas (Castilla y León, Extremadura).
In the Republic of Korea, Liriomyza huidobrensis (Diptera: Agromyzidae – EPPO A2 List) was found during a survey of potato pests carried out in 2011-2012. Localized outbreaks were observed in in potato fields in Miryang and Goryeong counties. This is the first published record of L. huidobrensis in the Republic of Korea, however some infestations on greenhouse crops had been observed earlier (Maharjan et al., 2014). Present, only in some areas (Miryang and Goryeong counties).
In Kenya, Meloidogyne enterolobii (EPPO A2 List) was first found during surveys conducted from May to June 2015 to determine the incidence of root-knot nematodes on Solanum scabrum. M. enterolobii was found in Yatta (Machakos county) on S. scabrum plants showing leaf yellowing, leaf drop and stunted growth (Chitambo et al., 2016). Present, only in some areas (Machakos county).
In Lebanon, a living specimen of Monochamus sutor sutor (a potential vector of Bursaphelenchus xylophilus) was detected in 2014. The adult female was found in the town of Jdaidet near Beirut. This is the first time that a Monochamus sp. is reported from Lebanon. It is noted that M. sutor sutor might have been introduced with wood packaging or timber import, and that it could represent a threat to pine forests in Lebanon (Moussa et al., 2016). Present, a single live specimen found near Beirut.
Basil downy mildew caused by Peronospora belbahrii is reported for the first time from the Republic of Korea. The disease was first observed in November 2015 on sweet basil (Ocimum basilicum) plants growing in plastic greenhouses in Gwangmyeong (Choi et al., 2016). Present, only in some areas (Gwangmyeong).
- Detailed records
In Arkansas (US), the mortality of approximately 20 sassafras trees (Sassafras albidum) observed near Warren (Bradley county) in December 2015 has been investigated. Results showed that these trees were infected by Raffaelea lauricola (EPPO Alert List). The insect vector, Xyleborus glabratus, was also present (Olatinwo et al., 2016).
In Brazil, bacterial fruit blotch caused by Acidovorax citrulli (EPPO A1 List) was first reported in 1990 in a watermelon (Citrullus lanatus) field in São Paulo state. The disease was then reported in melon (Cucumis melo) and watermelon crops in the states of Bahia, Ceará, Minas Gerais, Pernambuco, Rio Grande do Norte, Rio Grande do Sul, and Roraima. Outbreaks have only occurred sporadically in watermelon fields, but significant yield losses have been common in melon-producing areas during the rainy season, in particular in Rio Grande do Norte and Ceará which account for more than 80% of the Brazilian production of melons (Silva et al., 2017).
In autumn 2015, Thekopsora minima (EPPO Alert List) was detected for the first time in Oregon (US) in samples of Vaccinium corymbosum (cvs. Blue Crop, Jelly Bean, Peach Sorbet) which had been collected from different locations (Wiseman et al., 2016).
- Diagnostics
Nested and real-time PCR tests have been developed in the USA for the detection of Ceratocystis fagacearum (EPPO A1 List) in the sapwood of wilting oak trees (Quercus alba, Q. ellipsoidalis, Q. macrocarpa, Q. rubra), as well as from plant tissues taken the year following branch or whole-tree death (Yang & Juzwik, 2017).
- Host plants
During autumn 2015, grapevine plants (Vitis vinifera) showing leaf yellowing, veinal necrosis, and in some cases fruit shrivelling, were observed in a vineyard located in Piura, Northwestern Peru. As these symptoms resembled those of grapevine yellows, molecular tests for phytoplasma infection were implemented. Results revealed the presence of phytoplasma strains related to ‘Candidatus Phytoplasma brasiliense’. According to the authors, this is the first time that a ‘Ca. P. brasiliense’-related strain is associated with grapevine yellows (Wei et al., 2017).
In Spain, Erwinia amylovora (fireblight – EPPO A2 List) has been detected for the first time on the Iberian wild pear (Pyrus bourgaeana). P. bourgaeana is a deciduous tree growing in Mediterranean forests and evergreen open woodlands. Affected trees showed typical symptoms of fireblight, including blossom necrosis, leaf and shoot blight, fruit mummification and internal necrosis of twigs and branches (Marco-Noales et al., 2017).
- Modelling
The potential world distribution of Drosophila suzukii (Diptera: Drosophilidae – EPPO A2 List) has been studied using a predictive model. Results indicated high environmental suitability mainly in temperate and subtropical areas in Asia, Europe, North and South America, where D. suzukii has already been recorded. However, some areas in Africa and coastal Australia, where the pest is still absent, were also found to be at risk (dos Santos et al., 2017).
Sources
Chitambo O, Haukeland S, Fiaboe KKM, Kariuki GM, Grundler FMW (2016) First report of the root-knot nematode Meloidogyne enterolobii parasitizing African nightshades in Kenya. Plant Disease 100(9), p 1954.
Choi YJ, Choi IY, Lee KJ, Shin HD (2016) First report of downy mildew caused by Peronospora belbahrii on sweet basil (Ocimum basilicum) in Korea. Plant Disease 100(11), p 2335.
dos Santos LA, Mendes MF, Krüger AP, Blauth ML, Gottschalk MS, Garcia FRM (2017) Global potential distribution of Drosophila suzukii (Diptera, Drosophilidae). PLoS ONE 12(3): e0174318. https://doi.org/10.1371/journal.pone.0174318
Lim S, Igori D, Zhao F, Moon JS, Cho IS, Choi GS (2016) First report of Grapevine red blotch-associated virus on grapevine in Korea. Plant Disease 100(9), p 1957.
Maharjan R, Oh HW, Jung C (2014) Morphological and genetic characteristics of Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae) infesting potato crops in Korea. Journal of Asia-Pacific Entomology 17, 281-286.
Marco-Noales E, Peñalver J, Navarro I, Gorris MT, Morente MC, Balguerías C, Ramírez JA, Recio C, Ruiz de la Hermosa T, Sancho R, Aedo C, López MM (2017) Iberian wild pear (Pyrus bourgaeana) is a new host of Erwinia amylovora, the causal agent of fire blight. Plant Disease 101(3), p 502.
Moussa Z, Cocquempot C, Yammouni D (2016) First detection of pine wood nematode vector, Monochamus sutor sutor (Linnaeus, 1758) in Lebanon (Coleoptera, Cerambycidae, Lamiinae). Bulletin de la Société entomologique de France 121(4), 455-460.
Olatinwo R, Barton C, Fraedrich SW, Johnson W, Hwang J (2016) First report of laurel wilt, caused by Raffaelea lauricola, on sassafras (Sassafras albidum) in Arkansas. Plant Disease 100(11), p 2331.
Ruiz-García AB, Martínez C, Santiago R, García MT, de Prado N, Olmos A (2016) First report of Little cherry virus 1 (LChV-1) in sweet cherry in Spain. Plant Disease 100(11), p 2340.
Silva GM, Souza RM Yan L, Rui S Jr, Medeiros FHV, Walcott RR (2016) Strains of the group I lineage of Acidovorax citrulli, the causal agent of bacterial fruit blotch of cucurbitaceous crops, are predominant in Brazil. Phytopathology 106(12), 1486-1494.
Wei W, Pérez-López E, Bermúdez-Díaz L, Davis RE, Granda-Wong C, Zhao Y (2017) First report of a new grapevine yellows disease in Peru and its association with infection by a ‘Candidatus Phytoplasma brasiliense’-related phytoplasma strain. Plant Disease 101(3) p 502.
Wiseman MS, Gordon MI, Putnam ML (2016) First report of leaf rust caused by Thekopsora minima on Northern highbush blueberry in Oregon. Plant Disease 100(9), p 1949.
Yang A, Juzwik J (2017) Use of nested and real-time PCR for the detection of Ceratocystis fagacearum in the sapwood of diseased oak species in Minnesota. Plant Disease 101(3), 480-486