Range expansion of Lymantria dispar dispar (L.) (Lepidoptera: Erebidae) along its north-western margin in North America despite low predicted climatic suitability 

Group
University of Minnesota Forest Entomology Lab

Author Contact 
Aukema, Brian H. (bhaukema@umn.edu)

Funding information 
Sponsorship: APHIS Farm Bill A-83114 13255; APHIS Farm Bill 15-8130-0577-CA; USDA Forest Service award 14-JV-11242303-128

License 
CC0 1.0 Universal

Gypsy Moth Treatment Data (TrapData_TRTrm_2015.csv)

Who- Marissa Streifel, Aubree Kees, Brian Aukema, Patrick Tobin

What- This data contains weather data for 17 weather stations across the Arrowhead region of Minnesota. Theissen polygons were constructed around each weather station location. Gypsy moth trap data (catch & number of traps) were aggregated for each thiessen polygon and the corresponding weather data was used for analyses.

When- This data was collected from the NOAA and MesoWest (https://mesowest.utah.edu/) weather databases in the summer of 2013. The analyses were conducted for my Master’s research (2013-2016)

Where- This data represents the Arrowhead region of Minnesota (Cook, Lake, and St. Louis Counties)

Why- This data was used to see if there were any correlations between winter temperature and gypsy moth trap capture for the time period of interest (2004-2014).

Data referenced by- Streifel MA, Tobin PC, Kees AM, Aukema BH. Range expansion of Lymantria dispar dispar (L.) (Lepidoptera: Erebidae) along its north‐western margin in North America despite low predicted climatic suitability. J Biogeogr. 2018;00:1–12.
https://doi.org/10.1111/jbi.13474 

Variables-
• WeatherStation= name of weather station
• Year- year of weather data. Weather data for each year spanned from October of the previous year to April of the current year
• AbsMin- the absolute minimum temperature (Celsius) observed for the study year
• Days.belowNeg10C- the number of days that minimum temperatures dropped below a threshold of -10°C for the study year
• Days.belowNeg15C- the number of days that minimum temperatures dropped below a threshold of -15°C for the study year
• Days.belowNeg20C- the number of days that minimum temperatures dropped below a threshold of -20°C for the study year
• Days.belowNeg25C- the number of days that minimum temperatures dropped below a threshold of -25°C for the study year
• Days.belowNeg30C- the number of days that minimum temperatures dropped below a threshold of -30°C for the study year
• MeanMinJan- The average minimum temperature observed in January of the study year
• MeanMinDec- The average minimum temperature observed in December of the study year
• MeanMinFeb- The average minimum temperature observed in February of the study year
• Traps- the number of gypsy moth monitoring traps set in each Thiessen polygon for the study year
• Catch- the number of male gypsy moths captured in monitoring traps set in each Thiessen polygon for the study year
• Catch.Lag- This variable was included in an attempt to do a time series analysis, however, traps were not set in every Thiessen polygon every year for the study time period. Therefore this data is not appropriate for time series analyses
 
Gypsy moth egg mass overwintering mortality data (EggMass_Data_13-14.csv)

Who- Marissa Streifel, Aubree Kees, Brian Aukema, Patrick Tobin

What- This data contains overwintering mortality data for experimental gypsy moth egg masses that were allowed to overwinter on the Grand Portage Reservation in Minnesota

When- This field data was collected over the winter of 2014. Experimental egg masses were placed in at 12 field sites at heights above and below the average snow depth and on the north and south aspect of trees and allowed to overwinter

Where- Grand Portage Reservation

Why- This experimental data was used to determine if gypsy moth egg masses could overwinter in northern Minnesota. We were interested to see if snow provided any insulation which would increase the egg mass overwintering survival

Variables
• EggMass- Unique number assigned to each egg mass for identification
• Length_cm- length of each egg mass
• Width_cm- width of each egg mass
• Length_cm_r- “Length_cm” variable divided by 2
• Width_cm_r- “Width_cm” variable divided by 2
• TotalSurfaceArea_cm2- surface area of egg mass
• EggMassDensity- number of eggs divided by total surface area
• EggMassDensity_Infert- number of infertile eggs divided by total surface area
• FieldSite- field location of experimental egg mass
• Dist_M_Superior- Field site distance to Lake Superior in Meters
• Elevation_M- field site elevation in meters
• Aspect- placement of egg mass on north or south side of tree
• Height- Placement of egg mass above or below the average snow depth
• Larvae- number of larvae that emerged in spring
• Fertile nonemergent- the number of fertile eggs that did not emerge
• Infertile- number of infertile eggs
• TotalEggs- total number of fertile eggs in egg mass (fertile eggs + emerged larvae)
• TotalEggsInfert- total number of eggs in egg mass (fertile eggs+ emerged larvae+ infertile eggs)
• Proportion_Mortality- proportion of mortality for each egg mass
• Percent_Mortality- percent mortality (proportion mortality*100)
• DaysBelowNeg25- the number of days that minimum temperatures dropped below a threshold of -25°C as recorded by temperature data loggers in each field site at each egg mass location (above north, above south, below north, below south)
• DurationNeg25_H- the duration that temperatures were below a threshold of -25°C as recorded by temperature data loggers in each field site at each egg mass location (above north, above south, below north, below south)
• DaysBelowNeg27- the number of days that minimum temperatures dropped below a threshold of -27°C as recorded by temperature data loggers in each field site at each egg mass location (above north, above south, below north, below south)
• DurationNeg27_H- the duration that temperatures were below a threshold of -27°C as recorded by temperature data loggers in each field site at each egg mass location (above north, above south, below north, below south)
• DaysBelowNeg30- the number of days that minimum temperatures dropped below a threshold of -30°C as recorded by temperature data loggers in each field site at each egg mass location (above north, above south, below north, below south)
• DurationNeg30_H- the duration that temperatures were below a threshold of -30°C as recorded by temperature data loggers in each field site at each egg mass location (above north, above south, below north, below south)