The influence of polarized moonlight and collecting distance on the catches of winter moth Operophthera brumata (Lepidoptera: Geometridae) by light traps

Abstract

In this study we examine the relationship between the Lunar Phases and the efficiency of light traps in catching winter moth (Operophthera brumata Linnaeus, 1758). Our calculations are based on data collected by the Hungarian Forestry Light Trap Network at four sites from 1961 to 2008. We also tried to estimate the influence of polarized moonlight and collecting distance, which also depends on moonlight. Our investigations revealed that the catches were the greatest in the First and the Last Quarters, and the lowest at Full Moon. The reason for this is that the proportion of polarized moonlight in the different lunar quarters varies, with the catches highest when the proportion is greatest. Collecting distance has only a minor role.