XVII Annual Meeting of NAPPO
Reports from Canada, Mexico and USA at the XVII Annual Meeting of NAPPO at Villahermosa (MX) in 1993-10-18/22, highlighted several phytosanitary points from North America.
1. Lymantria dispar (Gypsy moth)
The Asian form of L. dispar (of which the females fly more freely than in the European form) was introduced into western area of North America by trans-Pacific trade in grain and timber. In British Columbia (CA), it was eradicated in 1992.
Since interception of gypsy moth egg masses associated with military equipment being repatriated from Europe to North America, the question has arisen whether this may concern the Asian form, possibly now present in Europe. This question must actively be investigated.
2. Tomicus piniperda, the pine shoot beetle now occurs in 6 of the Great Lakes State of USA, causing serious losses. Federal and State regulations have been imposed, controlling the movement of Christmas trees, logs, chips, etc. A limited infestation appeared in Canada, leading to new restrictions on material from USA. Eradication is considered impossible, but spread can be slowed.
3. The A2 mating type of Phytophthora infestans has spread from Mexico to several US States and one area in British Columbia (CA). Potato growers fear the possible effects of greater genetic recombination in the late blight fungus.
EPPO note: In the EPPO region, this mating type was briefly considered as a quarantine pest in the mid-1980s. This was abandoned when it was later found to be widespread. No particular consequences of its introduction have been proved, despite equivalent fears.
4. Eradication of Puccinia horiana is expected in California (US) in early 1994. Detection surveys carried out in other US states have given negative results. Attempts are also being made to eradicate the fungus in Mexico. P. horiana is an EPPO A2 quarantine pest.
5. A single incidence of Ips typographus (EC Annex IIB pest) was found in Pennsylvania (US). Traps were placed to check there were no further consequence of this regulatory incident.
6. The B biotype of Bemisia tabaci continues to cause serious losses in California (US) and also in Mexico. IPM programmes are being initiated, and parasites sought worldwide.
Sources
EPPO Secretariat, 1994-06.