Abstract

There is increasing evidence that plant-associated microorganisms are able to mediate plant-herbivorous insects-interactions. In this study, I evaluated the impact of two plant colonising fungi on three herbivorous insect species, using mycological, entomological and plant biochemistry techniques. In detail, my research focused on the mediation of two soil-borne fungi, the endophyte Acremonium alternatum and the fungal plant pathogen Verticillium longisporum on the preference and performance of three herbivorous insects with different feeding modes, Delia radicum L.(Diptera: Anthomyiidae), Plutella xylostella L. (Lepidoptera: Plutellidae) and Brevicoryne brassicae L. (Hemiptera: Aphididae). Two different cultivars of oilseed rape (Brassica napus and Brassica napus var.) were used. Host-preference of the herbivorous insects was tested by using mechanically damaged and intact plants either with endophyte infection (E+) or controls (E-) and plants inoculated with Verticillium (V+) or control (V-). Performance of insect feeding on infected /uninfected plants was evaluated by recording mortality of larvae, development time, pupal weight and fecundity. A field experiment was implemented to test the impact of endophyte inoculations on insect preference/performance relationships with regard to cabbage aphid population dynamics. Volatiles released from aerial plant part of infected or control plants were collected and analyzed qualitatively and quantitatively to explain host preference of adult herbivorous insects. The content and relative composition of four typical phytosterols, namely Sitosterol, Campesterol, Brassicasterol and Stigmasterol was quantified from the leaves and roots of infected and control plants to understand mechanisms of a fungal infection on insect performance.The results of the experiments can be summarized as follows:

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.