Recipient Organization
UNIVERSITY OF WASHINGTON
4333 BROOKLYN AVE NE
SEATTLE,WA 98195
Performing Department
Forest Ecology
Non Technical Summary
The Pacific Northwest (PNW) is a highly populated region and one of the fastest growing areas of the United States. Not surprisingly, the ports of Tacoma, Seattle, and Portland have become major ports-of-entry for foreign trade. The top five trading partners (in terms of value) for the port of Tacoma, for example, are countries in which the Asian gypsy moth (AGM) is native (China/Hong Kong, Japan, South Korea, Taiwan, and Vietnam). Moreover, over the last year, cargo has been re-routed through PNW ports due to congestion at other U.S. West Coast ports following contract negotiations between the Pacific Maritime Association and International Longshore and Warehouse Union. The AGM is not established in North America, and previous detections of AGM in North America have resulted in its successful eradication. However, previous detections of AGM in the PNW have generally been fewer in number (e.g., generally only 1-2 trapped males), limited in spatial scale (e.g., generally only 1-2 trap locations), and have not occurred since 2001 in Oregon and 1999 in Washington State. In 2015 so far, 8 AGM males have been trapped from seven different locations in Washington State (from Kent, WA to Vancouver, WA), and 2 AGM have been detected from the Portland area. These recent detection events greatly underscore the need to investigate potential emerging invasion pathways that could be facilitating the introduction of AGM into the PNW. In this study we will specifically seek to identify potential emerging AGM pathways in the PNW and quantify their contribution to AGM introduction. We will use existing datasets or develop new ones to accomplish our objectives. The immediate deliverable of this work is the development of an improved risk based model that aims to reduce the arrival and establishment of AGM in the PNW. We anticipate that this will greatly optimize detection efforts by the U.S. Customs Border Protection, which will consequently reduce the burden of State and Federal agencies responsible for AGM eradication programs. This is of paramount importance in the PNW due to the challenges associated with the implementation of eradication programs in heavily populated areas.
Animal Health Component
50%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
0%
Goals / Objectives
In this study we will identify potential emerging Asian gypsy moth (AGM) pathways in the Pacific Northwest and quantify their contribution to AGM introduction. The overarching goal is to improve and optimize detection efforts and management decisions.
Project Methods
In this project, we will compile existing datasets and develop new datasets to quantify the importance of existing Asian gypsy moth (AGM) pathways and identify emerging AGM pathways relevant to the Pacific Northwest (PNW) in an effort to optimize detection efforts and management decisions. Some of these datasets are readily available, but do not exist together in a combined geospatial database that is needed to efficiently identify new pathways. These existing and new datasets include:(1) Phenological predictions of gypsy moth seasonality. Phenological maps are available through a number of resources, including the program BioSIM (Régnière and Sharov 1998), which interpolates a selected gypsy moth phenology model, often the Gray egg hatch model (Gray 2009), over a digital elevation model (DEM). Such approaches have been used in the past by the cooperator when addressing gypsy moth invasions pathways (Tobin et al. 2010, Bigsby et al. 2011) and male moth flight behavior (Tobin et al. 2009). This data layer will be critical in identifying, and more importantly ranking, the temporal window of AGM introduction based on the AGM phenological predictions of the source port, the PNW port, and ports frequented by the cargo ship along the way. Such an approach was used very recently by Gray (2015, In Press) to broadly define AGM risks given gypsy moth phenology, shipping routes, and shipping schedules. The generalized framework provided by Gray (2015) will be specifically applied and tailored to PNW ports and PNW climatic conditions that drive AGM seasonality.(2) Climatic thresholds of gypsy moth. Current phenology models have been used in the past to determine climatic suitability of the gypsy moth in North America (Gray 2004); these efforts are based on overwintering survivorship (i.e., excluding areas too cold to allow gypsy moth to survive over the winter) and life stage completion (i.e., excluding areas where an insufficient amount of degree days are present to allow development to the adult stage, or areas where there is an insufficient amount of cooling required to terminate diapause). Only very recently have supraoptimal temperatures - excessively high summer temperatures that negatively impact larval development - been considered (Tobin et al. 2014a). Current efforts by the cooperator are examining the role that supraoptimal temperatures have played in both outbreak dynamics of the European gypsy moth (EGM) in the northeastern U.S., and in EGM eradication efforts in the western U.S. Adding this new upper limit threshold layer, coupled with existing lower temperature threshold layers (Gray 2004), into the model will provide an additional and previously ignored input that could greatly influence the success or failure of an introduced AGM population.(3) AGM outbreak history in its native habitat. Past work by the cooperator has shown a significant temporal lag between EGM outbreaks in the northeastern U.S. and gypsy moth eradication efforts in the western U.S. (Tobin et al. 2012); this analysis revealed that western eradication programs were highest 3-4 years following outbreaks in the east, likely as a result of human movement of life stages during, for example cross-country household moves, given the temporal lag between initial gypsy moth arrival and detection (Liebhold and Tobin 2006). It is not yet known how AGM outbreaks in native environments have influenced detection of AGM in the PNW. We will analyze the temporal correlation between AGM native outbreaks and historical detections of AGM in the U.S., using methods previously used by the cooperator (Tobin et al. 2012), and incorporate this finding into our decision model.(4) AGM host plant abundance. Past work has led to the development of a suitable host plant map for EGM based exclusively on preferred host plant species (Morin et al. 2005). Because AGM has a far greater host range than EGM, we will use existing host plant species records to develop a spatial layer of AGM host suitability, according to methods by Morin et al. (2005). We will also expand on this prior effort by separately considering both primary host species (defined as host species in which all instars can feed without any loss in developmental time and/or adult fitness) and secondary host species (defined as host species on which some instar can feed but often with a reduction in developmental time and/or adult fitness). Having both a primary and secondary host plant layer would facilitate a more precise quantification of the probability of AGM establishment and hence be useful in a final decision model that seeks to quantify the strength of AGM pathways.(5) Cargo ship trajectory. Working with cooperators from the U.S. Customs Border Protection in Seattle, WA and Portland, OR, we will incorporate the complete cargo ship trajectory in our final model, from initial source to final destination in the PNW while including stops at ports along the way. Stops at ports prior to PNW will be assessed relative to gypsy moth phenology and background AGM outbreak intensity to better quantify risk.