First report of Steinernema carpocapsae from Moghan region and its biocontrol potential against Agrotis segetum in laboratory condition
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عنوان دوره: سومین کنگره بین المللی حشره شناسی ایران
نویسندگان
1Biological Control Research Department, Iranian Research Institute of Plant Protection, AREEO, Tehran, Iran,
2Nematology Research Department, Iranian Research Institute of Plant Protection, Iran,
3Plant Protection Research Department, Ardabil Agricultural and Natural Resources Research and Education Center, AREEO, Moghan, Iran,
چکیده
During a survey of entomopathogenic nematodes (EPNs) in Moghan region, Iran, in 2015, a steinernematid species was isolated using the Galleria-baiting method. Based on its morphological and phylogenetic analysis of molecular data, the isolate was identified as Steinernema carpocapsae. The ITS rDNA sequence was deposited in NCBI with accession number of MF187617. Nucleotide row data was edited using MEGA 6.0 software and Homologous sequences were involved in analysis using Blast software. Sequences were aligned using Clustal W and bootstrap analysis was conducted. The phylogenetic tree was constructed by the maximum likelihood method using MEGA 6.0 software and Steinernema feltiae was used as outgroup. The lethal effect of S. carpocapsae (Moghan isolate) was evaluated against last instar larvae of the common cutworm, Agrotis segetum as an important and destructive pest in Moghan in the laboratory conditions. Rearing and bioassay conditions were 26 ± 1 °C, 70 ± 10% RH and 16:8 h L:D. Plastic cups (9 cm height and 7.5 cm diameter) which were filled with 250 g autoclaved moist sandy soil (85% sand, 10% silt and 5% clay and 10% moisture (w / w) were used as experimental units. Infective juveniles were added in certain concentrations in 0.5 ml of water to the surface of the soil, separately. Finally, the individual larva was placed on the soil and the cups were covered with ventilated lids to avoid desiccation. Control cups received 0.5 ml of distilled water. Fifteen cups were used for each nematode concentration and the control. The experiment was replicated three times. The cadavers were counted after 7 days. The bioassay results showed high susceptibility of the larvae to S. carpocapsae. The LC10, LC50 and LC90 values were 9.9, 54.13, and 246.2 IJs (infective juveniles) per larva of the pest, respectively (Χ2= 7.36; df=3, P value= 0.061).
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