120°W
50°N
100°W
80°W
60°W
European Gypsy Moth Lymantria dispar dispar
Establishment Suitability for 2014
50°N
30°N
30°N
Establishment Suitability
Unsuitable Climate
Urban Deciduous Tree Canopy
No Preferred Host
0 50 100
Preferred Host Presence
200
300
400
500
Miles
Albers Equal Area Conic Projection
100°W
Map produced by FHTET, IL
Fort Collins, CO on 5-13-2014
Gypsy_Moth_Establishment_mask.mxd
80°W
European Gypsy Moth Establishment Suitability Summary for 2014
Lymantria dispar dispar
The European Gypsy Moth Establishment Suitability surface for 2014 was produced for the Contiguous 48 U.S. (CONUS) at a 240 meter
resolution by the U.S. Forest Service (FS), Forest Health Protection, Forest Health Technology Enterprise Team (FHTET) in collaboration with the
Animal and Plant Health Service, Plant Protection and Quarantine (APHIS PPQ) staff, U.S. Geological Survey (USGS), and the European Gypsy
Moth Advisory Group. The intended use is to identify areas suitable for European gypsy moth establishment based on preferred host availability, urban
deciduous tree canopy, and climate suitability (Table 1). Areas were masked out from the Detection Likelihood analysis where: 1) climate extremes are
not suitable for gypsy moth survival, and 2) where no preferred host occurs (Liebhold et al. 1995, Table 2).
Table 1: Description of host and climate layers used to create the Gypsy Moth Establishment surface.
Gypsy Moth Preferred
Host Mask
Urban Deciduous Tree
Canopy
BioSim Gypsy Moth
Climate Suitability
Mask
The gypsy moth host preference mask was created by adding basal area estimates (Ellenwood 2013) for all host genera with the highest suitability
ranking of 1 (Liebhold et. al. 1995, Table 2). *Note basal area estimates for Madrone were not available. Madrone presence was estimated by
intersecting the Madrone distribution range (Little 1971) with NLCD deciduous and mixed forest land cover.
NLCD deciduous tree canopy intersected with urban areas used to represent the potential distribution of planted host trees within urban areas
(Withrow 2010).
The climate mask was created by: 1) taking the maximum suitability value between the 30-year norm surface and the most recent 2-year surface; 2)
intersecting the 2012 gypsy moth detection data with the max probability surface and finding the 95% quantile probability; 3) reclass the max
probability surface with the 95% threshold value (0.075); 4) using the county boundaries to create an additional county mask value of 1 for Cook
County, MN where significant detections occurred despite threshold cutoff, perhaps due to lake effects or other climate interpolation limitations; 5)
adding the threshold suitability map with the county mask, and finally; 6) reclass again to a 0, 1 final mask.
Table 2: Preferred gypsy moth hosts
used in the host suitability mask.
Common Name
Genus
Larch
Larix
Birch
Betula
Hawthorn
Crataegus
Sweetgum
Liquidambar
Apple
Malus
Hophornbeam
Ostrya
Cottonwood
Populus
Oak
Quercus
Willow
Salix
Basswood
Tilia
Tan Oak
Lithocarpus
Madrone*
Arbutus
menziesii
Working Group
Downing, Marla C. – USFS FHTET
Leinwand, Ian I. F. – FHTET contractor
Withrow, John R. – FHTET contractor
Cook, Gericke L. – APHIS PPQ
Kenneway, Lisa F. – APHIS PPQ
Jarnovich, Catherine – USGS
Sapio, Frank J. – USFS FTHET
Advisory Group
Chaloux, Paul – APHIS
Lance, David R – APHIS
Liebhold, Andrew – USFS NRS
Man-Son-Hing, Anthony – APHIS
Mastro, Victor C – APHIS
McPherren, Patrick W – APHIS
Spaulding, Julie S – APHIS
Krist, Jr., F.J., Ellenwood, J.R., Woods, M., McMahan, A., Cowardin, J., Ryerson, D., Sapio, F., Zweifler, M., Romero,
S.A. 2014. 2013 – 2027 National Insect and Disease Forest Risk Assessment. Fort Collins, Colorado: USDA Forest Service, Forest
Health Technology Enterprise Team, FHTET-14-01.
Liebhold, Andrew M. et al. 1995. Suitability of North American tree species to gypsy moth: a summary of field and laboratory tests.
Gen. Tech. Rep. NE-211. Radnor, PA: USDA, Forest Service, Northeastern Forest Experiment Station. 34 p.
Little, E.L., Jr., 1971, Atlas of United States trees, volume 1, conifers and important hardwoods: U.S. Department of Agriculture
Miscellaneous Publication 1146, 9 p., 200 maps.
Withrow, J. 2010. Production of Urban Host Layers. Deliverable document prepared for USDA Forest Service, Forest Health
Technology Enterprise Team (FHTET), Task Order No: AG-7604-D-09-0542. WAO No: FHTET-10-Pest-Host.
Point of Contact: Marla C. Downing, USDA Forest Service, Forest Health Protection, Forest Health Technology Enterprise Team
(FHTET), 2150 Centre’ Ave., Bldg A, Suite 331 Fort Collins, CO 80526-8121. Phone: 970-295-5843, Email: mdowning@fs.fed.us