The Influences of Weather and Moonlight on the Light Trap Catches of Moths

Abstract

A quantitative evaluation of the influences of weather and moonlight conditions on the light trap catches of moths was needed to compare samples of different stands and time.Multiple regression analysis was employed to establish which factors were important in determining the collected number of species and individuals and other characteristics of a moth sample. Data of seventeen August samplings taken from 20 : 00-21 : 00 and the weather and moonlihgt conditions prevailing at that same time were used. Regression analyses showed that most of the variation in the number of collected species could be described by an equation involving wind velocity, fog density, change in temperature from the previous night and lightness of the sky during the night. Standard partial regression coefficient showed that fog density was the most important positive effect component and wind velocity the main negative effect component. The equation for estimating the number of collected individuals described a smaller portion of the variability than the number of species. Air temperature did not significantly affect either the number of species or individuals.