Nachwuchswissenschaftlerforum / Young Scientists Meeting 2015 Saar et al.

Determination of the potential of the entomopathogenic fungi fumosorosea as a BCA against pest insects

Katharina Saar1, Jasmin Philippi2, Edgar Schliephake2, Andreas Leclerque3, Manuel Werner1, Johannes A. Jehle1, Dietrich Stephan1 1 Institute for Biological Control, Julius Kühn Institute, Darmstadt 2 Institute for Resistance Research and Stress Tolerance; Julius Kühn Institute, Quedlinburg 3 Institute for Microbiology and Biochemistry, Geisenheim University, Geisenheim Email of corresponding author: [email protected]

Entomopathogenic fungi like Isaria sp., The feeding of on plants may Metarhizium sp. and Beauveria sp. are cause direct damage to the leaves as important biological control agents due well as virus transmission by their to their lethal effects against several sucking behaviour. In addition to the insect pests. The aim of the EU-funded mortality effects, insects showed project BIOCOMES is therefore the use changes within their behaviour when of the natural ubiquitous entomo- they were infected with I. fumosorosea. pathogenic Isaria fumosorosea In order to evaluate whether adults of (: : Cordy- B. tabaci, which had been infected and cipitaceae) in an integrated pest man- non-infected with Isaria, showed agement strategy to control pest in- differences in their feeding (sucking) sects in greenhouses. behaviour, the electrical penetration The selection of highly virulent and ef- graph method (EPG) was used to fective strains is one of the necessary observe behavioural changes, e.g. prerequisites. Therefore, several strains penetration frequencies. First results of of Isaria sp., obtained from different the comparisons concerning the geographical origins and hosts, were changes within the waveform and compared for their efficacy and viru- durations will be shown. lence against various pest insect species from the orders Lepidoptera and Presently, different molecular methods Hemiptera. By means of various patho- like RFLP are used for the characteriza- genicity assays, the efficacy and median tion of virulence factors and differences lethal concentration (LC50) of different between the strains of I. fumosorosea Isaria strains against Spodoptora exigua from different geographical origins and (beet armyworm) and Bemisia tabaci hosts and its influence on different ac- () were investigated. Depending tivity patterns as mentioned above. on the Isaria strain, the mortality rates differed from 30 % to 76 %.

20 Berichte aus dem Julius Kühn-Institut 181