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
Tomato chlorosis virus (Crinivirus, ToCV – EPPO A2 List) occurs in South Africa. In Mpumalanga province, ToCV has been detected in field and protected tomato (Solanum lycopersicum) crops and weeds (Datura stramonium) growing nearby (Moodley et al., 2016). Present, no details.
- Detailed records
Symptoms of chestnut blight were first observed in November 2011 on Castanea sativa on the island of Corfu (GR). Laboratory analysis confirmed the occurrence of Cryphonectria parasitica (EPPO A2 List). According to the authors, this is the first report of C. parasitica on the island of Corfu, one of the few areas in the country thought to be free of the disease (Tziros and Diamandis, 2016).
In the Republic of Korea, Erwinia amylovora (EPPO A2 List) was reported for the first time in pear (Pyrus sp.) orchards in May 2015 in the cities of Anseong and Cheonan (EPPO RS 2015/089). In June and July 2015, typical symptoms of fireblight were also observed on shoots and leaves of apple (Malus domestica) in 2 commercial orchards located in the cities of Anseong and Jecheon. Eradication is continuing (Myung et al., 2016).
From 2009 to 2012, surveys on Diplodia pinea, Fusarium circinatum (EPPO A2 List) and Mycosphaerella spp. have been conducted in Pinus radiata plantations in Pais Vasco (ES). Results showed that D. pinea caused shoot blight in 24% of sampled plantations. Fusarium circinatum and Mycosphaerella spp. were detected in 15 and 71% of surveyed plantations, respectively (Iturritxa et al., 2015).
Grapevine Pinot gris virus (Trichovirus, GPGV) occurs in British Columbia, Canada (Poojari et al., 2016).
Until recently, ‘Candidatus Phytoplasma solani’ (EPPO A2 List) had only been detected in Montenegro in association with bois noir disease of grapevine. However, during a study conducted in July and August 2015, the pathogen was detected in symptomatic potato (Solanum tuberosum) plants at 2 locations in Central Montenegro (Nikšić and Danilovgrad). In both locations, approximately 10 to 15% of the plants showed symptoms of potato stolbur (i.e. leaf redness and yellowing, swollen stems, and aerial tuber formation). Laboratory analysis (PCR, RFLP, sequencing) confirmed the presence of ‘Ca. P. solani’ (Radonjić et al., 2016).
Laurel wilt, caused by Raffaelea lauricola (EPPO Alert List), a fungal symbiont of the redbay ambrosia beetle (Xyleborus glabratus) occurs in Texas (US). In March 2015, dead and dying redbay trees (Persea borbonia) were observed near Lumberton, in Hardin county. The identity of the fungus was confirmed by laboratory studies (morphology, sequencing, pathogenicity tests). A survey for symptomatic trees was conducted in areas around Lumberton in May 2015, and the pathogen was isolated from wilted redbay trees at 3 additional locations in Hardin and Jasper counties, ranging from 3 to 23 km west and northwest of the original location. The vector, X. glabratus, was trapped at several sites around Lumberton (Menard et al., 2016).
- Diagnostics
A multiplex real-time PCR has been developed for the simultaneous detection and differentiation of the four bacteria that are associated with bacterial spot of tomato (EPPO A2 List): Xanthomonas euvesicatoria, X. vesicatoria, X. perforans and X. gardneri (Strayer et al., 2016).
- Host plants
In Sicilia (IT), Rhynchophorus ferrugineus (Coleoptera Curculionidae - EPPO A2 List) has been found mainly on Phoenix canariensis, as well as on several other Arecaceae in urban environments (Phoenix dactylifera, Washingtonia spp., Chamaerops humilis, Syagrus romanzoffiana, Jubaea chilensis, Howea forsteriana, Livistona chinensis), and on Chamaerops humilis in natural conditions. In September 2015, the pest was found in wither and dying plants of Strelitzia nicolai (Strelitziaceae) growing in the ‘Bioparco di Sicilia’ (Carini, Palermo province). Several larvae and cocoons were collected at their bases and an exit hole was observed on a stem. This is the first time that a Strelitzia species is reported to host R. ferrugineus (Fiorello et al., 2015).
- Epidemiology
Studies on the long-term survival of Acidovorax citrulli (EPPO A1 List) in seeds of Citrullus lanatus var. citroides (citron melon) have indicated that the bacterium may survive in these seeds for at least 7 years (Dutta et al., 2014).
Studies have been carried out to determine the length of time Potato spindle tuber viroid (Pospiviroid, PSTVd – EPPO A2 List) remains infective in extracted tomato leaf sap on common surfaces. When sap from PSTVd-infected tomato leaves was applied to 8 common surfaces (cotton, wood, rubber tire, leather, metal, plastic, human skin, and string) and left for various periods of time (5 min to 24 h) before rehydrating the surface and rubbing onto healthy tomato plants, PSTVd remained infective for 24 h on all surfaces except human skin. It survived best on leather, plastic, and string. It survived less well after 6 h on wood, cotton, and rubber and after 60 min on metal. On human skin, PSTVd remained infective for only 30 min. These results highlight the importance of good hygiene practices to ensure effective management of PSTVd (Mackie et al., 2015).
- New pests
Tomato necrotic streak virus (Ilarvirus, TomNSV) is newly described virus which has been observed on tomato (Solanum lycopersicum) crops in Florida (US) at a relatively low incidence since 2013. Affected tomato plants show necrotic streaks along the leaflet veins and necrotic rings or spots on fruits (Badillo-Varguas et al., 2016).
Outbreaks of a rust disease have been observed in eucalyptus forestry plantations and nurseries in Kenya, Mozambique and South Africa since 2009. Studies have shown that these outbreaks were associated with a new fungus species Phakopsora myrtacearum sp. nov. This new rust species has been found on at least 3 Eucalyptus species, E. cloeziana, E. grandis, and E. nitens. It is considered that P. myrtacearum might be a threat to eucalyptus trees grown for forestry purposes. However, its host range and potential economic impacts remain to be further studied (Maier et al., 2016).
Sources
Badillo-Vargas IE, Baker CA, Turechek WW, Frantz G, Mellinger HC, Funderburk JE, Adkins S (2016) Genomic and biological characterization of Tomato necrotic streak virus, a novel subgroup 2 Ilarvirus infecting tomato in Florida. Plant Disease 100(6), 1046-1053.
Dutta B, Sanders H, Langston DB, Booth C, Smith S, Gitaitis RD (2014) Long-term survival of Acidovorax citrulli in citron melon (Citrullus lanatus var. citroides) seeds. Plant Pathology 63, 1130–1137.
Fiorello A, Speciale M, Lo Verde G, Massa B (2015) Strelitzia nicolai (Strelitziaceae), new host plant for Rhynchophorus ferrugineus (Coleoptera Curculionidae) in Sicily. Naturalista siciliano 39(2), 435-438.
Iturritxa E, Mesanza N, Brenning A (2015), Spatial analysis of the risk of major forest diseases in Monterey pine plantations. Plant Pathology 64, 880–889.
Mackie EA, Coutts BA, Barbetti MJ, Rodoni BC, McKirdy SJ, Jones RAC (2015) Potato spindle tuber viroid: stability on common surfaces and inactivation with disinfectants. Plant Disease 99(6), 770-775.
Maier W, McTaggart AR, Roux J, Wingfield MJ (2016) Phakopsora myrtacearum sp. nov., a newly described rust (Pucciniales) on eucalypts in eastern and southern Africa. Plant Pathology 65(2), 189–195.
Menard RD, Clarke SR, Fraedrich SW, Harrington TC (2016) First report of laurel wilt, caused by Raffaelea lauricola, on redbay (Persea borbonia) in Texas. Plant Disease 100(7), p 1502.
Moodley V, Gubba A, Mafongoya PL (2016) Occurrence of Tomato chlorosis virus (ToCV) on Datura stramonium near tomato crops (Solanum lycopersicum) in South Africa. Plant Disease 100(7), p 1512.
Myung IS, Lee JY, Yun MJ, Lee YH, Lee YK, Park DH, Oh CS (2016) Fire blight of apple, caused by Erwinia amylovora, a new disease in Korea. Plant Disease 100(8), 1774-1774.
Poojari S, Lowery T, Rott M, Schmidt AM, Úrbez-Torres JR (2016) First report of Grapevine Pinot gris virus in British Columbia, Canada. Plant Disease 100(7), p 1513.
Radonjić S, Hrnčić S, Kosovac A, Krstić O, Mitrović M, Jović J, Toševski I (2016) First report of ‘Candidatus Phytoplasma solani’ associated with potato stolbur disease in Montenegro. Plant Disease 100(8), p 1775.
Strayer AL, Jeyaprakash A, Minsavage GV, Timilsina S, Vallad GE, Jones JB, Paret ML (2016) A multiplex real-time PCR assay differentiates four Xanthomonas species associated with bacterial spot of tomato. Plant Disease 100(8), 1660-1668.
Tziros GT, Diamandis S (2016) First report of chestnut blight caused by Cryphonectria parasitica on European chestnut (Castanea sativa) on Corfu Island, Greece. Plant Disease 100(7), p 1502.