Matilda Gikonyo

   Department of Insect Symbiosis
   Research Group Sequestration and Detoxification in Insects
 Phone:+49 (0)3641 57 1555Max Planck Institute for Chemical Ecology
 Fax:+49 (0)3641 57 1502Hans-Knöll-Straße 8
  emailD-07745 Jena

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There are more than 1 million phytophagous insect species and more than 300,000 plant species producing hundreds of thousands of specialized metabolites as defense against herbivores. The “escape and radiate” hypothesis proposed by Ehrlich and Raven in 1964 suggests that evolutionary novel insect adaptations to plant chemical defenses promoted species diversification of plants and plant-feeding insects. The genus Psylliodes contains more than 169 species which mainly feed on the plant families Brassicaceae, Solanaceae and Poaceae, containing very different chemical defense compounds. Interestingly, more than half of the species feed on Brassicaceae which contains the glucosinolate-myrosinase defense system. We hypothesize that host plant shifts enabled by adaptations to chemical defenses have played an important role in the species diversification of Psylliodes flea beetles. The goal of my project is to reconstruct the phylogenetic relationship of Psylliodes species and trace the host plant shifts in this genus. For this purpose, I develop a set of suitable single copy nuclear markers [e.g. Carbamoyl phosphate synthase, RNA polymerase II 215kD and Serine-Threonine protein kinase] for the phylogenetic reconstruction. This species phylogeny will provide the framework to identify key evolutionary adaptations of Psylliodes to plant defenses, e.g. the glucosinolate-myrosinase system.

last updated on 2021-06-30