Date of this Version
Ecology 52:6 (November 1971), pp. 999–1007.
Nocturnal insect activity was observed through telescopes focused on the moon. Flight direction was computed and methods were developed for estimating height and determining vertical distribution. Total density was correlated with light-trap catches; effective range of a light-trap was about 7 meters. Species identification was impossible but the method was selective for larger and higher-flying insects. Characteristics of insect activity observed during periods of army cutworm abundance indicate that it orients to the west during spring migration. Activity and altitude of flight were modified by wind direction and velocity, but flight direction during migration was independent of wind.