| Gypsy Moth in Oregon 2008 |
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| 2007 detection and 2008 eradication programs |
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ODA detected twelve gypsy moths in 2007 at five new sites and one old site. All moths were genetically tested by the USDA Otis Pest Survey, Detection and Exclusion Laboratory. Tests showed that all moths were the North American strain. Six gypsy moths were caught in one trap in Shady Cove, an old site. This is the area where two gypsy moths were caught in 2005 and another two caught in 2006. The source of this infestation was a 5th wheel trailer. A resident visited a relative in Pennsylvania while hauling the 5th wheeler during June 2007. A live egg mass and other life stages were collected underneath the 5th wheel trailer. As a result, three aerial treatments of Bacillus thuringiensis var. kurstaki (Btk) were applied by helicopter to 336 acres in Shady Cove to eliminate the gypsy moth infestation in spring 2008.
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| 2008 gypsy moth survey program |
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ODA maintains a high-level detection program for gypsy moth, Lymantria dispar, and its Asian strain (Asian gypsy moth). In 2008, about 17,579 Asian gypsy moth and gypsy moth traps were placed statewide. Most traps are placed in western Oregon where population centers and host plants are located. Other potential introduction sites such as national parks, campgrounds, and RV parks, are also trapped. Detection traps are placed at densities of 2-4 traps per square mile in cities and 1-2 traps per square mile in rural areas.
Delimitation traps are placed at densities of 16-49 traps for five square miles for two years at sites where gypsy moths are detected. Delimitation traps are placed following the initial detection to delimit new infestations the same year if possible. Delimitation traps are also placed to monitor the success of eradication programs. The core of an eradication area may be mass-trapped at densities of up to nine traps/acre. Early detection of infestations has allowed eradication programs to become smaller and less costly, a benefit for everyone.
No moths were found at six sites where single gypsy moths were caught in 2006. These include three separate sites in Portland (Multnomah County), one site in Damascus (Clackamas County), one site in O’Brien (Josephine County), and another in Eugene (Lane County). These sites can now be declared free of gypsy moth.
No moths were found at four sites where single gypsy moths were caught in 2007; in Sunriver (Deschutes County), Wasco (Sherman County), Murphy (Josephine County), and near Clatskanie (Columbia County). Another year of negative delimitation trapping will be required before these sites can be declared free of gypsy moth.
Twelve gypsy moths were caught in 2008 at one old site and four new sites. All moths were submitted to the USDA Otis Pest Survey, Detection and Exclusion Laboratory and were determined by genetic analysis to be the North American strain. Seven gypsy moths were caught in five traps in SE Eugene near the site where two moths were caught in 2007, indicating a breeding population at this site. Single gypsy moths were detected at three new sites: in NE and NW Portland (Multnomah County) and in NW Portland (Washington County). Two gypsy moths were also caught in a trap at a new site about three miles southwest of Eugene (Lane County). Delimitation trapping will be conducted in 2009 around all 2007 and 2008 positive sites.
No moths were found at three previous eradication sites. In 2007, ODA sprayed a 533-acre gypsy moth eradication area in Bend and a 640-acre Asian gypsy moth eradication area in St. Helens. In 2008, ODA sprayed on 336 acres in Shady Cove. The gypsy moth infestation in Bend is now declared eradicated after two years of negative trapping. One more year of negative delimitation trapping for Asian gypsy moth in St. Helens and one more year of negative delimitation trapping for gypsy moth in Shady Cove are required before these infestations can be declared eradicated.
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| Asian gypsy moth detection program |
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Populations of Asian gypsy moth in Asia and the Russian Far East continue to pose a threat. International trade and commerce activities continue to increase the likelihood of new introductions. Asian gypsy moth was found in British Columbia in 1995 and 1996; in Washington in 1996, 1997, and 1999; in Oregon in 1991, 2000, and 2006; in California in 2003, 2005, 2006, and 2007; and in Idaho in 2004. In 2008, more than 20 ships with Asian gypsy moth egg masses were intercepted in the west and south coast states (WA, OR, CA, TX). An Asian gypsy moth trapped in 2004 near a railroad line in Idaho suggests that containers or cargo are a pathway for Asian gypsy moth into the interior of the United States. These pathways and detections highlight the need for continued vigilance to keep Asian gypsy moth from entering and establishing in Oregon and the Pacific Northwest.
In 2008, about 7,246 Asian gypsy moth traps were placed statewide. The Asian gypsy moth delimitation area in St. Helens was trapped according to the established delimitation protocol. Additionally, major ports and waterways at risk from ships carrying Asian gypsy moth egg masses were also trapped. The Columbia River from Astoria to Portland (about 90 miles) and the port of Coos Bay (Coos County) are trapped at high densities. The port and waterway survey consists of nine traps per square mile for three miles, followed by four traps/ mi2 for another two miles. Asian gypsy moth traps were placed around the port of Coos Bay at nine traps/mi2.
This year, the Asian gypsy moth trapping program was expanded to include major cities, highways, and railroads at risk to receive or transport cargos and containers originating from Asia. As a result, significantly more Asian gypsy moth traps were placed; about 7,246 traps in 2008 versus 4,033 traps in 2007.
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| Potential gypsy moth eradication program for 2009 |
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ODA has conducted numerous gypsy moth eradication programs since 1981. These have ranged from large-scale aerial spray programs of 225,000 acres to small ground application of four acres.
Distribution of gypsy moth pest alerts, egg mass searches, and information gathering from residents are continuing at the Eugene site where gypsy moths were caught in 2008 and 2007. Plans are still being developed. Aerial applications of Btk by helicopter may be proposed for about 623 acres in Eugene in the spring of 2009. Analysis of the data from this site is ongoing and consultation with the US Fish and Wildlife Service is anticipated before these proposals are finalized.
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