Metadata "Data from: cold winters drive consistent and spatially synchronous 8-year population cycles of cabbage stem flea beetle" A monitoring program for P. chrysocephala in southern Sweden winter oilseed rape fields started in 1969. These data were collected over a 50-year period from commercial winter oilseed rape fields across Scania, the southernmost county in Sweden, by the Swedish University of Agricultural Sciences and its predecessors involved in the monitoring program. The sampling region of Scania, Sweden was divided into five subregions: (1) southeast, (2) southwest, (3) west, (4) northeast, and (5) northwest. For each subregion we also included daily maximum and minimum temperature data in Celsius from 1968-2018. The total area planted to winter oilseed rape in Scania is reported. The mean regional number of cold days and North Atlantic Oscillation index are reported. Lastly, P. chrysocephala density in winter oilseed rape across five subregions in the UK from 2001-2020 are extracted from a plot in a public report. For further information, see methods in the publication Emery et al. 2023. Cold winters drive consistent and spatially synchronous 8-year population cycles of cabbage stem flea beetle. Journal of Animal Ecology. File information metadata for CSFB_Scania_NAs2010-11.csv The data in the file have information on crop planting date, the total number of Psylliodes chrysocephala larvae detected, number of plants sampled, the density of larva (total larvae/plants examined), sampling date, year, subregion, whether a seed coating or spray pesticide was used in the field and whether the sample was from a commercial field or from an experiment. 16 variables, 3118 rows. All blanks in these data were interpolated as described in the manuscript. 16 column variables described as below- HarvestYear: year the oilseed rape was harvested. This is to clarify because some cabbage stem flea beetle larval density samples were taken in December of the previous year, but it reflects the population that would emerge the following year in the same oilseed rape planting Subregion: subregion was the classification level used to sort data into different subpopulations. Subregions are Northeast, Northwest, West, Southeast and Southwest DateSampled: Date is formatted according to ISO 8601 (YYYY-MM-DD) DateNumSampled: datenum is based on an origin date of 1 January 1900 and a running numeric value MonthSampled: Month sampled is the numeric month within the year in which sampling was done PlantsSampled : PlantsSampled is the number of oilseed rape or turnip plants dissected to look for cabbage stem flea beetle larvae MeanLarvae: MeanLarvae is TotNumLarvae over PlantsSampled TotNumLarvae: total larvae counted across all plants sampled SeedingDate: Seeding date is the day-month the crop was planted SeedingJulDays: is the SeedingDate in numeric within year format (Julian day) SeedCoated: SeedCoated is a binary with either yes or no PreventionSpray: PreventionSpray indicates whether any spray pesticides were used if known with either No or Yes PesticideTreatment: Treatment indicates whether either seeding coating was used (SeedOnly), Prevention Spray was used (SprayOnly), both, none or incomplete- meaning unknown for at least one Crop: Crop is either WOSR = winter oilseed rape or TurnipRape = turnip rape CropCertainty: whether we are positive about the crop type or not, options are WOSR = winter oilseed rape, TurnipRape = turnip rape and WOSRAssumed= assumed winter oilseed rape SampleType: R = routine sample taken once over the winter from commercial field, M = Monthly sample: Sample originates from a parallell sampling schedule where fields were sampled monthly, but only one sample per field (from March, or the timepoint closest to March sampled) have been included in this database, to avoid pseudo-replication F = Samples from experiments. One sample per experiment, but if the experiments contained different insecticide treatment options against cabbage stem flea beetles, one sample per treatment has been entered Metadata for weather from five subregions (NorthwestInsectYear.csv, NortheastInsectYear.csv, SoutheastInsectYear.csv, SouthwestInsectYear.csv, WestInsectYear.csv) Five files have daily maximum and minimum temperatures in degrees Celsius for each subregion from August 1968-2019. All weather data comes from Swedish weather data website, last accessed in 2020 at https://www.smhi.se/data. 18,566 rows in the NorthwestInsectYear.csv 18,606 rows in the NortheastInsectYear.csv 18,574 rows in the SoutheastInsectYear.csv 18,574 rows in the SouthwestInsectYear.csv 18,574 rows in the WestInsectYear.csv 8 column variables in each file as described below- DateNum: the date in sequential numbers with an origin date of 1 January 1900 Tmin: the minimum temperature in degrees Celsius on that date Tmax: the maximum temperature in degrees Celsius on that date Station: The weather station name used from the Swedish Meteorological and Hydrological Institute (Barkokra with Munka Ljungby as backup and HelsingborgA for one month in 2017 for the Northwest, Osby or Kristianstad for the Northeast, Bollerup with Skillinge for one month in 1996 for Southeast, Falsterbo for the Southwest, Lund for the West). Swedish weather data last accessed in 2020. https://www.smhi.se/data RegionEn: the subregion in English for which the station is matched in this data set (Northwest, Northeast, Southwest, Southeast, West) newDate: Date is formatted according to ISO 8601 (YYYY-MM-DD) JulDays: the Julian day of that date within the calendar year (1-365) HarvestYear: the harvest year for which the weather data are matched (harvest year for cabbage stem flea beetle data- eg 1969, environmental data from the 24 August the year of planting (1968)to the 23 August the year of Harvest 1969 would all be weather data for harvest year 1969) Metadata for WOSRareaSkane1968-present.csv These data are from The Swedish Board of Agriculture, https://statistik.sjv.se/ last accessed 1 December 2022 on the number of hectares planted to winter oilseed rape, turnip rape and the combined total in the Scania region in Sweden from 1968 (matching with harvest year 1969) to 2019. Last accessed in August 2020. 53 rows and 5 column variables- YearArea: Indicates the year the crop was planted (it's the autumn/year before the harvest year) HarvestYear: The year the crop is harvested WinterOilseedRape.hectare: The total number of hectares planted to winter oilseed rape in Scania, Sweden WinterTurnipRape.hectare: The total number of hectares planted to turnip rape in Scania, Sweden TotalWOSRTurnipRape.hectare: total number of hectares planted to either winter oilseed rape or turnip rape (sum of previous two columns) Metadata for NAO_coldDays.csv This file has the annual Hurrell PC-Based North Atlantic Oscillation Index value from NCAR UCAR https://climatedataguide.ucar.edu/climate-data/hurrell-north-atlantic-oscillation-nao-index-pc-based last accessed in 2022 as well as the raw and log-transformed (natural log, base e) regional mean number of cold days (below -10C) per year for Scania. 5 column variables with 51 rows- HarvestYear: Year in which the winter oilseed rape is harvested NumVeryColdDaysRaw: Regional mean number of days below -10 degrees Celsius across the five subregions from autumn previous to the harvest year until the mean sample date for which larval densities were assessed in the winter oilseed rape fields (usually March of HarvestYear) NumVeryColdDaysLog: Natural log (base e) of NumVeryColdDaysRaw + 0.1 NAOyear: Year from which North Atlantic Oscillation data was pulled, matches Harvest Year NAOlevel: North Atlantic Oscillation level from the annual Hurrell PC-Based North Atlantic Oscillation Index. Last accessed in August 2022, https://climatedataguide.ucar.edu/climate-data/hurrell-north-atlantic-oscillation-nao-index-pc-based Metadata for CSFBinUK2001-2020.csv The data in the file is extracted from the “historical comparisons” figure from the Crop Monitor report last accessed 7 November, 2022 at https://www.cropmonitor.co.uk/wosr/surveys/wosrPestAssLab.cfm?year=2006/2007&season=Autumn. These data include the regions in the UK that data was collected from, the harvest year and the mean number of cabbage stem flea beetle larvae counted per plant in each subregion/year. 3 column variables and 101 rows. Variables described as follows- Subregion: one of five subregions the cabbage stem flea beetle larval data was collected from in winter oilseed rape in England including East, MidlandsWest, North, Southeast and Southwest HarvestYear: numeric variable indicating the year the winter oilseed rape was harvested (2001-2020) CSFBperPlant: The mean number of cabbage stem flea beetle (Psylliodes chrysocephala) larva counted per winter oilseed rape plant in each subregion per year