Experiment to determine the oviposition behavior and locomotor activity ofHomoeosoma nebulellumDenis and Schiffermüller were conducted under laboratory conditions with a photoperiod of 16:8 (L:D). When provided with oviposition sites dusted with sunflower pollen, females began to lay eggs on the day following mating, with a maximum fecundity during the first 2 d. During a single life span, the total fecundity per female ranged from 50 to 337 eggs (167.9 ± 72.2) ($\bar x$± SD). Most eggs were laid during the first 2 h of the scotophase. Locomotor activity of individuals of both sexes was recorded during the scotophase. Virgin females were active mainly at the beginning and end of this period. The activity of virgin males increased at the end of the scotophase, which coincides with female calling behavior. Mated females without oviposition sites showed a high and sustained level of activity.