New data on quarantine pests and pests of the EPPO Alert List
By browsing through the literature, the EPPO Secretariat has extracted the following new data concerning quarantine pests and pests included on the EPPO Alert List. The situation of the pest concerned is indicated in bold, using the terms of ISPM no. 8.
New geographical records
Citrus huanglongbing or citrus greening caused by Liberibacter asiaticus (EPPO A1 quarantine pest) is reported in Papua New Guinea. It has been detected in one location (Sandaun Province, formerly West Sepik) near the border with Indonesia (Promed, 2003). The Australian Quarantine Inspection Service (AQIS) has confirmed the presence of the pathogen in Papua New Guinea. AQIS had also detected L. asiaticus in the Indonesian part of the island (Irian Jaya) in 1999 and in East Timor in 2000 which is also a new record for the EPPO Secretariat (AQIS web site). Situation of L. asiaticus in Papua New Guinea: Present, found in Sandaun Province. Situation of L. asiaticus in East Timor: Present, no details.
Studies on the presence of Phytophthora species were done in southern Sweden on 32 oak stands (27 with predominantly declining trees, 5 with predominantly healthy trees). Phytophthora quercina (EPPO Alert List) was found in 10 of the 27 declining stands. P. cactorum and P. cambivora were recovered from one stand each. No Phytophthora species were found in healthy oak stands. It is felt that P. quercina is widespread in southern Sweden and that it could be one of the factors involved in oak decline. This is the first report of P. quercina in Sweden. This paper from Jönsson et al. (2003) also mentions the presence of P. quercina in Belgium, Serbia, and United Kingdom which are new records according to the EPPO Secretariat. Situation of P. quercina in Sweden: Present, widespread in the south.
Situation of P. quercina in Belgium, Serbia and Montenegro, and United Kingdom: Present, no details.
Incursions of Anastrepha ludens (EPPO A1 quarantine pest) are reported in USA: California (Valley Center) and Texas; eradication programmes are being applied (APHIS, 2003). In Florida, larvae were found in Pinellas county in May 2003 on Capsicum pubescens (University of Florida Pest Alert, 2003).
A few adults of Anastrepha serpentina were trapped in January 2003 in grapefruit orchards and various citrus trees in private gardens, in the Lower Rio Grande Valley of Texas, US. Eradication measures are being applied (NAPPO - Official Pest Notifications, 2003).
Globodera rostochiensis (EPPO A2 quarantine pest) has been found in one potato field in Steuben County, New York, US. This is the first time since 1986 that the nematode has been found outside the quarantine area. So far, G. rostochiensis remains confined to portions of 9 counties within the State of New York (NAPPO pest Alert, 2003)
A US isolate of Pepino mosaic potexvirus (EPPO Alert List) has been characterized and its genome sequenced. So far, the virus has been detected in tomato samples from Arizona, California, Colorado, Florida, Oklahoma and Texas (see also EPPO RS 2001/158). This confirms the presence of Pepino mosaic potexvirus in USA (Maroon-Lango et al., 2003).
More than 100 suspect cultures of Ralstonia solanacearum (EPPO A2 quarantine pest) were isolated from diseased potato plants from different regions of Russia in 2001-2002, and studied to identify the races and biovars present. As a result, 37 strains were considered as R. solanacearum race 1 and 59 strains as race 3 (of which 51 were determined as race 3 biovar 2). This confirms the presence of R. solanacearum race 3 biovar 2 in Russia. It is noted that brown rot can cause severe losses in potato and tomato in some regions of Russia, but no details are given on its distribution within the country (Matveeva et al, 2003).
New host plants
Pantoea stewartii (EPPO A2 quarantine pest) was detected in the weed Setaria lutescens, which could act as an alternative host of the bacterium (Esker et al., 2003).
In the Lower Rio Grande Valley of Texas (US), 4 periods of cold from 1951 to 1989 drastically reduced the area of commercial citrus, as well as the number of trees affected by citrus psorosis (EU Annexes). In addition, the use of a new psorosis-free cultivar of grapefruit (cv. Rio Red) contributed to the reduction of disease incidence. However, during the past 6 years, more symptoms of psorosis were observed in the field and pattern of infection seemed to follow flood-irrigated rows, both observations suggesting a natural spread of psorosis. Examination of sections of roots and of soil collected from affected trees, revealed the presence of an Olpidium-like fungus with resting spores. Further studies will be done on the possible role of this type of fungus in the natural transmission of citrus psorosis (Miao et al., 2003).
Since 1980, massive mortality of oak trees (more than 200,000 per year) has been observed in western coastal areas of Honshu, Japan. This disorder was formerly included as ‘fungal oak disease’ on the EPPO Alert List. Many ambrosia beetles (Platypus quercivorus) were found on stems of dead trees, but infested trees were not always killed. A new fungal species called Raffaelea quercivora sp. nov. (an anamorphic Ascomycete) was isolated from discoloured sapwood, necrotic inner bark, beetle body surfaces and galleries. Inoculation tests confirmed its pathogenicity to Quercus serrata and Q. crispula. It is suggested that the extensive mortality of oaks observed in Japan is caused by R. quercivora and its vector P. quercivorus (Ito et al., 2003). Considering the high mortality on oaks observed in Japan, the EPPO Secretariat decided to add again this disease to the EPPO Alert List.
Esker, P.D.; Aalsburg, J.; Nutter Jr, F.W. (2003) Survey of alternative hosts for Pantoea stewartii, causal organism of Stewart’s disease in Iowa. Abstract of a paper presented at the APS Annual Meeting (Charlotte, US, 2003-08-09/13). Phytopathology 93(6), supplement, S24.
Ito, S.; Murata, M.; Yamada, T. (2003) Massive mortality of Fagaceous trees in Japan. Abstract of a paper presented at the APS Annual Meeting (Charlotte, US, 2003-08-09/13). Phytopathology 93(6), supplement, S102.
Jönsson, U.; Lundberg, L.; Sonesson, K.; Jung, T. (2003) First records of soilborne Phytophthora species in Swedish oak forests. Forest Pathology, 33(3), 175-179.
Maroo-Lango, Guaragna, M.A.; Jordan, R.L.; Bandla, M.; Marquardt, S. (2003) Detection and characterization of a US isolate of Pepino mosaic potexvirus. Abstract of a paper presented at the APS Annual Meeting (Charlotte, US, 2003-08-09/13). Phytopathology 93(6), supplement, S57.
Matveeva, E.V.; Pekhtereva, E.Sh.; Nikolaeva, E.V.; Schaad, N.W. (2003) Pathogenicity, virulence, and phenotypic diversity of Ralstonia solanacearum strains in potato in Russian Federation. Abstract of a paper presented at the APS Annual Meeting (Charlotte, US, 2003-08-09/13). Phytopathology 93(6), supplement, S58.
Miao, H.; Seyran, M.; deGraca, J.V.; Skaria, M. (2003) Circumstantial evidence of natural spread of Citrus psorosis virus in Texas. Abstract of a paper presented at the APS Annual Meeting (Charlotte, US, 2003-08-09/13). Phytopathology 93(6), supplement, S61-62.
APHIS - Pest Detection and Management Programs. Weekly Notice, April 28, 2003. http://www.aphis.usda.gov/ppq/ep/reports/weekly/weekly4_28_03.pdf
Australian Quarantine and Inspection Service Web site. AQIS keeps weather eye on citrus industry’s Yellow Dragon’ in PNG. http://www.affa.gov.au/ministers/truss/releases/02/02326wt.html
NAPPO Pest Alert – Official notifications - USA. Golden nematode Globodera rostochiensis, detection in Fremont, New York – 2003-06-12. http://www.pestalert.org
NAPPO Pest Alert - Official Pest Notifications – USA. Sapote fruit fly, Anastrepha serpentina (Wiedemann), quarantine in Texas – 2003-02-07. http://www.pestalert.org
ProMED posting of 2003-05-27. Citrus Huanglongbin – Papua New Guinea (Sandaun). http://www.promedmail.org
University of Florida Pest Alert. Mexican fruit fly larvae and adult, 2003-06-19. http://extlab7.entnem.ufl.edu/PestAlert/