Sample collection
Winter moth males were collected using pheromone-baited traps (Elkinton
et al., 2010; Elkinton, Lance, Boettner, Khrimian, & Leva, 2011) from
locations in Europe, North Africa, and western Asia, as well as from the
four regions in North America, where established winter moth populations
have been recorded (Nova Scotia, British Columbia, Oregon, and the
northeastern United States, Figure 1). In addition, larval individuals
and adult females, which are wingless and do not fly, were
opportunistically collected (see supplemental Appendix S1 Table S1 for
complete collection information, including life stages).
After collection, adult moths were placed in glassine envelopes (Uline
Corporation, USA) and stored at either -20°C or -80°C, and larval
caterpillars were placed in 95% ethanol and stored at -20°C. For many
of the moths included in our analysis, collection and genotype
information was previously reported (e.g., Andersen, Havill, Caccone, &
Elkinton, 2017; Andersen et al., 2019a,b, In Press) (Supplemental
Appendix S1 Table S1).