Université de Fribourg

Discordances between phylogenetic and morphological patterns in alpine leaf beetles attest to an intricate biogeographic history of lineages in postglacial Europe

Triponez, Yann ; Buerki, Sven ; Borer, Matthias ; Naisbit, Russel E. ; Rahier, Martine ; Alvarez, Nadir

In: Molecular Ecology, 2011, vol. 20, no. 11, p. 2442–2463

Pleistocene glacial and interglacial periods have moulded the evolutionary history of European cold-adapted organisms. The role of the different mountain massifs has, however, not been accurately investigated in the case of high-altitude insect species. Here, we focus on three closely related species of non-flying leaf beetles of the genus Oreina (Coleoptera, Chrysomelidae), which are often found...

Université de Neuchâtel

Multi-species phylogeographic investigations in closely-related taxa and mutualistic plant-insect systems

Triponez, Yann ; Alvarez, Nadir (Dir.) ; Rahier, Martine (Codir.)

Thèse de doctorat : Université de Neuchâtel, 2010.

Phylogeography is the study of historical processes responsible for the contemporary geographic distributions of individuals and gene lineages. Studying species in space and time combining ecology and genetics allows disentangling patterns at the boundary between biogeography, population genetics and evolutionary ecology. As until now in Europe (but also in a very large portion of the World) many...

Université de Neuchâtel

Genetic and Environmental Sources of Variation in the Autogenous Chemical Defense of a Leaf Beetle

Triponez, Yann ; Naisbit, Russell. E. ; Jean-Denis, J. B. ; Rahier, Martine ; Alvarez, Nadir

In: Journal of Chemical Ecology, 2007, vol. 33, no. 11, p. 2011-2024

Chemical defense plays a central role for many herbivorous insects in their interactions with predators and host plants. The leaf beetle genus Oreina (Coleoptera, Chrysomelidae) includes species able to both sequester pyrrolizidine alkaloids and autogenously produce cardenolides. Sequestered compounds are clearly related to patterns of host-plant use, but variation in de novo...

Université de Neuchâtel

The Role of Indole and Other Shikimic Acid Derived Maize Volatiles in the Attraction of Two Parasitic Wasps

D'Alessandro, Marco ; Held, Matthias ; Triponez, Yann ; Turlings, Ted C. J.

In: Journal of Chemical Ecology, 2006, vol. 32, no. 2, p. 2733-2748

After herbivore attack, plants release a plethora of different volatile organic compounds (VOCs), which results in odor blends that are attractive to predators and parasitoids of these herbivores. VOCs in the odor blends emitted by maize plants (Zea mays) infested by lepidopteran larvae are well characterized. They are derived from at least three different biochemical pathways, but the...