Population fluctuation of egg parasitoids of sunn pest and determining of dominant species in Varamin and vicinity

Subject Areas : Plant Pests

Hasan Ghahari ¹ (Associate Professor of Entomology; Young Researchers and Elites Club, Yadegar-e- Imam Khomeini (RAH), Shahre Rey Branch, Islamic Azad University, Tehran, Iran)

Received: 2015-05-13 Accepted : 2015-08-11 Published : 2015-08-23

Keywords: Population fluctuation, parasitoid, Encyrtidae, Sunn pest, Scelionidae, Varamin, Dominant species,

Abstract :

Population fluctuation of sunn pests’ parasitoids (Scelionidae and Encyrtidae) was studied in 5 different localities of Varamin including, Javad-Abad, Dehmacin, Gharchak, Asgar-Abad and Pishva. Seven parasitoid species including, Telenomuschloropus, Trissolcusbasalis, Tr. grandis, Tr. rufiventris, Tr. semistriatus, Tr. vassilievi and Ooencyrtustelenomicida were collected from the mentioned regions. Upon the samplings in Gharchak, 4 species, T. semistriatus, T. grandis, T. Vassilievi and T. Rufiventris, were collected which of these T. semistriatus and T. grandis were determined as dominant species. Mean percent parasitism of T. semistriatus was higher than the other species and the highest parasitism (44.63%) was obtained in 22 May 2014. In Pishva, 5 parasitoids, T. grandis, T. vassilievi, T. semistriatus, T. chloropus and T. Basalis, were collected, which T. grandisand T. vassilievi were the dominant. The parasitism of these two parasitoids were started in 10 April 2014 and the maximum parasitism of T. grandis(27.89%) in 22 May 2014 and for T. vassilievi (22.39%) in 29 May 2014. Parasitoids of sunn pest in Javad-Abad were identified as T. rufiventris, T. grandis and Telenomus chloropus which of these, T. rufiventris was determined as the dominant species. The beginning of its parasitism activity was observed in 17 April 2014 and its maximum (26.44%) in 7 May 2014. The collected species in Dehmacin were included T. semistriatus, T. vassilievi, T. grandis and O. telenomicida which 2 species T. semistriatus and O. telenomicida were the dominant. The maximum percent parasitism was obtained in 22 May 2014 for T. semistriatus and 29 May 2014 for O. telenomicida. Six parasitoid species including, O. telenomicida, T. rufiventris, T. vassilievi, T. grandis, T. semistriatus and T. simony were collected from Asgar-Abad, which of these 3 first species were the dominant species. The highest percent parasitism for T. vassilievi(16.68%) and T. rufiventris (13.21%) was obtained in 22 May, 2014, and for T. grandis(23.72%)in 5 June 2014. Regarding to sex ratio of parasitoids, mean percent of emerged females was more than the male production in all sampled regions.