The population fluctuations of Asymmetrasca decedens (Paoli, 1932) and Zyginidia pullula (Boheman, 1845) (Homoptera: Cicadellidae) in maize fields in Izmir [Izmir ili misir tarlalarinda Asymmetrasca decedens (Paoli, 1932) ve Zyginidia pullula (Boheman, 1845) (Homoptera: Cicadellidae) türlerinin populasyon degişimi]

This study was carried out during the years of 2004-2005 in Menemen- Izmir (Turkey) with aim to determine the population fluctuations of Asymmetrasca decedens (Paoli, 1932) and Zyginidia pullula (Boheman, 1845) (Homoptera: Cicadellidae). The species were collected weekly within june - october by using yellow sticky traps from four different maize fields. With this study similarity in population fluctuations of A. decedens and Z. pullula to each other was shown and their presence in first and second crop maize vegetations was determined. The populations of each species began to increase at the 2-4 leaf stage of first maize crop and reached its highest levels at the harvest stage. After this stage, rapid decrease in the population of A. decedens and Z. pullula was seen due to maturation of plants of first crop. During the same time, the pests reached their highest population density in the second crop maize which was in 2-4 leaf stage providing abundance of fresh food for the pests. The population of the pests in the second crop decreased significantly close to harvest period, reaching to zero at harvest time. In both years the population density of A. decedens and Z. pullula in first crop, were lower than in second year crops. The comparison of the experimental data showed that the adults numbers found in 2005 were higher than in the previous year.