| Population Fluctuation and Spatial Distribution Pattern of Sesamia cretica (Lepidoptera: Noctuidae) in Southeastern Tehran |
| Paper ID : 1145-3IICE (R1) |
| Authors: |
|
Roya Arbab Tafti *1, Yaghoub Fathipour2, Hossein Ranjbar Aghdam3 1Dept of Agril Entomology, IRIPP 2Tarbiat Modares University 3Research Department of Agricultural Entomology, Iranian Research Institute of Plant Protection. |
| Abstract: |
| The main characteristics in a sampling and integrated pest management program are to determine the population density and spatial pattern of insects. Therefore, population density and dispersion pattern of Sesamia cretica Lederer was studied on maize in Varamin (Ahmadabad and Khaveh) and Rey (Aminabad and Talebabad) area (Tehran, Iran) during 2017 and 2018. The highest population density of S. cretica larvae per plant was recorded on 4 and 8 October in Aminabad, 17 and 20 September in Talebabad, 6 and 17 September in Ahmadabad and Khaveh in 2017 and 2018 respectively. Mean density of the pest per plant was 52.62 ± 12.53, 10.5 ± 2.85, 17.45 ± 3.48, 7.57 ± 1.55 in 2017 and 12 ± 5.29, 1 ± 0.3, 11.05 ± 2.36, 12 ± 3.41 in 2018 in Aminabad, Talebabad, Ahmadabad and Khaveh respectively. The spatial distribution pattern of S. cretica was designated by using dispersion index of variance-to-mean-ratio, Taylor's power law and Iwao's patchiness regression method in addition to Morisita's coefficient. Based on the index of dispersion, the spatial distribution of S. cretica in all fields in both areas was aggregated during the two years of the current study except for Aminabad in 2018. According to Taylor's model, Ahmadabad and Aminabad in 2017 had a random pattern while other fields in two areas had an aggregated spatial distribution during these two sampling years. Based on P values in Iwao's model, the regression between the mean crowding and the density was no significant in Aminabad and Khaveh in 2017 and Talebabad in 2018 while in other fields indicating an aggregated spatial distribution. In Morisita’s index spatial distribution pattern was aggregated, but in few sampling dates it was random in four fields and two areas in 2017 and 2018. The results revealed that population density of S. cretica was affected by the region but in spatial distribution pattern, oviposition behavior of the pest was much more determining than the region. The coefficients of the spatial pattern can be used for improving the sampling program to calculate the population density of S. cretica precisely. |
| Keywords: |
| Dispersal pattern, Pink stem borer, Population fluctuation, Sampling program |
| Status : Paper Accepted (Poster Presentation) |
