Table 2.

Candidate and selected variables used to model climatic suitability of I. pacificus in California

Candidate variables	Selected variables
Annual mean temperature (BIO1)
Mean diurnal temperature range (BIO2)
Isothermality (BIO3)	x
Temperature seasonality (BIO4)
Max. temperature of warmest month (BIO5)	x
Min. temperature of coldest month (BIO6)
Temperature annual range (BIO7)
Mean temperature of wettest quarter (BIO8)
Mean temperature of driest quarter (BIO9)
Mean temperature of warmest quarter (BIO10)
Mean temperature of coldest quarter (BIO11)	x
Annual precipitation (BIO12)
Precipitation of wettest month (BIO13)
Precipitation of driest month (BIO14)
Precipitation seasonality (BIO15)	x
Precipitation of wettest quarter (BIO16)
Precipitation of driest quarter (BIO17)
Precipitation of warmest quarter (BIO18)	x
Precipitation of coldest quarter (BIO19)	x
Average day length annual
Average day length winter (Dec., Jan., Feb.)
Average day length summer (Jun., Jul., Aug.)	x
Average day length spring (Mar., Apr., May)
Average day length fall (Sep., Oct., Nov.)
Average growing degree days annual
Average growing degree days winter (Dec., Jan., Feb.)
Average growing degree days summer (Jun., Jul., Aug.)
Average growing degree days spring (Mar., Apr., May)
Average growing degree days fall (Sep., Oct., Nov.)
Annual average number of days with snow depth > 1 mm
Average vapor pressure annual
Average vapor pressure winter (Dec., Jan., Feb.)
Average vapor pressure summer (Jun., Jul., Aug.)
Average vapor pressure spring (Mar., Apr., May)
Average vapor pressure fall (Sep., Oct., Nov.)	x