tailieunhanh - Virulence and horizontal transmission of Beauveria pseudobassiana S.A. Rehner & Humber in Ips sexdentatus and Ips typographus (Coleoptera: Curculionidae)

Our results indicate that B. pseudobassiana ARSEF 9271 is a promising microbial control agent against the tested Ips species and can horizontally spread among a population of both I. sexdentatus and I. typographus. | Turkish Journal of Agriculture and Forestry Turk J Agric For (2016) 40: 241-248 © TÜBİTAK doi: Research Article Virulence and horizontal transmission of Beauveria pseudobassiana . Rehner & Humber in Ips sexdentatus and Ips typographus (Coleoptera: Curculionidae) 1 2 3 1 1, Seda KOCAÇEVİK , Ali SEVİM , Mahmut EROĞLU , Zihni DEMİRBAĞ , İsmail DEMİR * 1 Department of Biology, Faculty of Sciences, Karadeniz Technical University, Trabzon, Turkey 2 Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Ahi Evran University, Kırşehir, Turkey 3 Department of Forestry Engineering, Faculty of Forestry, Karadeniz Technical University, Trabzon, Turkey Received: Accepted/Published Online: Final Version: Abstract: Ips sexdentatus (Boerner) and I. typographus (Linnaeus) (Coleoptera: Curculionidae) are considered to be important destructive pests of coniferous forests in Europe and Asia. In this study, the efficacy of Beauveria pseudobassiana strain ARSEF 9271 isolated from Dendroctonus micans (Kugelann) (Coleoptera: Curculionidae) was evaluated against I. sexdentatus and I. typographus adults. Insects were treated with different conidial concentrations of the fungus to determine the virulence. A conidial suspension of 1 × 108 conidia mL–1 caused 100% mortality in both I. sexdentatus and I. typographus within 5 and 7 days, respectively. Additionally, 100% mycosis was obtained in the concentration-response experiments for both insects. LC50 values of the fungus were calculated as × 104 conidia mL–1 and × 104 conidia mL–1 for I. sexdentatus and I. typographus, respectively. I. sexdentatus and I. typographus adults were also inoculated with a conidial suspension of 1 × 106 conidia mL–1 at inoculation rates of 0% (control), 25%, 50%, 75%, and 100% to determine the horizontal transmission of the fungus. Mortality values from horizontal .