Investigation of fungal pathogens of potato beetle (Leptinotarsa decemlineata, Coleoptera Chrysomelidae) and development of prototype fungal conrtol product

In this study, firstly, 12 fungal pathogens were isolated from dead potato beetle cadavers on farmland and the isolates were numbered as Ld 1-12. Morphological and molecular characterization studies revealed that the isolates were Beauveria bassiana. In screening tests, LdA 1 at 1x107 spore/ml concentration was determined as the most effective isolate with 80% and 50% mortality rates on larvae and adults, respectively. In the dose trials, LdA 1 isolate showed a 100% and 47% mortality effect at the end of the seventh day in larvae and adults at a concentration of 1x108 spores/ml. As a result of dose trials, LC50 values for larvae and adults were calculated as 0.2x106 (0.03-1.15) and 0.17x108 (0.002-1.411), respectively. The oil formulation (Crysomelicidal) of this isolate was developed and it was determined that in pot experiments under laboratory conditions, it showed 100%, 97% mortality, and 100% mycosis in both larvae and adults at a concentration of 1x108 spores/ml, respectively. The commercial product Nostalgist showed 27% and 3% mortality and 0% mycosis in larvae and adults, respectively, under the same conditions. The LC50 value of the formulation was calculated as 1.2x106 (0.3-4.8) in larvae and 0.2x107 (0.06-0.9) adults. In addition, it was determined that this product was effective on Agalastica alni and Xanthogaleruca luteola from the family Crysomelisidea.