The subject of our investigation was the visual features of wing color with special focus on the UV reflectance in the green-veined white butterfly (Pieris napi).Previous studies had concluded that UV reflectance on dorsal wing surfaces is found only in the female P.napi.Based on UV sensitive photography,we analyzed a correlation between 12 geographic and environmental factors and UV reflectance pattes on 3 patches on the forewings of 407 P napi specimens from the Palaearctic region.Results had shown that females significantly differ from males:they exhibit a 25％ higher UV reflectance.To investigate whether and how UV reflectance levels on the forewings and hindwings of both sexes are influenced by the environment,we performed a principal component analysis (PCA) with several environmental variables.For several variables (in particular,latitude and longitude,mean annual temperature and precipitation,and temperature annual range and altitude),the generalized linear model (GLM) model revealed a significant correlation in both sexes.This suggests a link between UV reflectance levels and the environment and distribution of P.napi.We found that stronger UV reflectance is associated with generally more hostile environments and concluded that large-scale environmental factors influence the UV reflectance on the forewings of both male and female green-veined white butterflies.