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Université de Neuchâtel

Colour polymorphism in the leaf beetle genus 'Oreina'

Van Noort, Tom ; Benrey, Betty (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2013.

This dissertation investigates the maintenance of colour polymorphism in the leaf beetle genus Oreina CHEVROLAT (Coleoptera; Chrysomelidae). The remarkable colour variation in this seemingly aposematic and chemically defended genus forms a paradox with current scientific views concerning predator learning and mimicry. Using a variety of approaches we explore the selective forces that...

Université de Neuchâtel

Phylogeography and biodiversity in an alpine leaf beetle genus

Borer, Mattias ; Rahier, Martine (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2009 ; Th. 2110.

Des changements dans la conformation tectonique et orbitale de la terre (excentricité, obliquité et la précession) ont entraîné des oscillations récurrentes du climat pendant le Quaternaire. Ces oscillations ont fortement influencé le paysage génétique de la flore et de la faune contemporaines, notamment en ce qui concerne le continent Européen. Pendant les périodes glaciaires,...

Université de Neuchâtel

Selective sequestration and metabolism of plant derived pyrrolizidine alkaloids by chrysomelid leaf beetles

Hartmann, Thomas ; Witte, Ludger ; Ehmke, Adelheid ; Theuring, Claudine ; Rowell-Rahier, Martine ; Pasteels, Jacques M.

In: Phytochemistry, 1997, vol. 45, no. 3, p. 489-497

Pyrrolizidine alkaloids (PAs) are assumed to function as plant defence compounds against herbivory. A number of adapted insects are known to sequester plant derived PAs for their own benefit. Here we summarize the chemical interactions between leaf beetles of the genus Oreina (Coleoptera, Chrysomelidae) and their host plants Adenostyles spp., Senecio nemorensis, and S....

Université de Neuchâtel

Host-Plant Switches and the Evolution of Chemical Defense and Life History in the Leaf Beetle Genus Oreina

Dobler, Susanne ; Mardulyn, Patrick ; Pasteels, Jacques M. ; Rowell-Rahier, Martine

In: Evolution, 1996, vol. 50, no. 6, p. 2373-2386

Insect-plant interactions have played a prominent role in investigating phylogenetic constraints in the evolution of ecological traits. The patterns of host association among specialized insects have often been described as highly conservative, yet not all specialized herbivorous insect lineages display the same degree of fidelity to their host plants. In this paper, we present an estimate of the...

Université de Neuchâtel

A comparison between allozyme data and phenotypic distances from defensive secretion in Oreina leaf-beetles (Chrysomelinae)

Rowell-Rahier, Martine ; Pasteels, Jacques M.

In: Journal of Evolutionary Biology, 1994, vol. 7, no. 4, p. 489-500

The genetic relationships between five Oreina species (Chrysomelidae, Coleoptera) were studied. Of these species, four (O. bifrons, O. gloriosa, O. speciosa, O. variabilis) feed on Apiaceae and secrete mixtures of autogenous cardenolides from defensive glands, whilst the other (O. speciosissima) feeds on Asteraceae and is able both to produce cardenolides and to...

Université de Neuchâtel

The chemical ecology of defense in arthropods

Pasteels, Jacques M. ; Grégoire, J. C. ; Rowell-Rahier, Martine

In: Annual Review of Entomology, 1983, vol. 28, p. 263-289

Oreina cacaliae (Coleoptera, Chrysomelidae) produces in its elytral and pronotal defensive secretion seneciphylline N-oxide together with small amounts of another pyrrolizidine alkaloid tentatively identified as senecionine N-oxide. This is a strong departure from the chemical composition of the defensive secretions in related species, characterized by complex mixtures of cardenolides,...

Université de Neuchâtel

Pyrrolizidine alkaloids of probable host-plant origin in the pronotal and elytral secretion of the leaf beetle Oreina cacaliae

Rowell-Rahier, Martine ; Pasteels, Jacques M. ; Randoux, T. ; Braekman, J. C. ; Daloze, D.

In: Entomologia Experimentalis et Applicata, 1988, vol. 49, no. 1-2, p. 55-58

Oreina cacaliae (Coleoptera, Chrysomelidae) produces in its elytral and pronotal defensive secretion seneciphylline N-oxide together with small amounts of another pyrrolizidine alkaloid tentatively identified as senecionine N-oxide. This is a strong departure from the chemical composition of the defensive secretions in related species, characterized by complex mixtures of cardenolides,...

Université de Neuchâtel

Reproductive biology of viviparous and oviparous species of the leaf beetle genus Oreina

Dobler, Susanne ; Rowell-Rahier, Martine

In: Entomologia Experimentalis et Applicata, 1996, vol. 80, no. 2, p. 375-388

In five species of the genus Oreina Chevrolat (Coleoptera, Chrysomelidae) we compared the size of offspring, the fecundity of the females, the timing of offspring production and female investment over the season. Two of the species, O. elongata and O. luctuosa, laid eggs, while O. cacaliae, O. gloriosa and O. variabilis gave birth to larvae. Offspring...

Université de Neuchâtel

Sequestration of ingested [14C]senecionine N-oxide in the exocrine defensive secretions of chrysomelid beetles

Ehmke, Adelheid ; Rowell-Rahier, Martine ; Pasteels, Jacques M. ; Hartmann, Thomas

In: Journal of Chemical Ecology, 1991, vol. 17, no. 12, p. 2367-2379

Oreina cacaliae (Chrysomelidae) sequesters in its elytral and pronotal defensive secretion the N-oxides of pyrrolizidine alkaloids (PA N-oxides) from its food plant Adenostyles alliariae (Asteraceae). [14C]Senecionine N-oxide was applied for detailed studies of PA N-oxide sequestration. An average of 11.4% of total radioactivity is taken up by...

Université de Neuchâtel

Sequestration of plant pyrrolizidine alkaloids by chrysomelid beetles and selective transfer into the defensive secretions

Rowell-Rahier, Martine ; Witte, Ludger ; Ehmke, Adelheid ; Hartmann, Thomas ; Pasteels, Jacques M.

In: Chemoecology, 1991, vol. 2, no. 1, p. 41-48

Oreina cacaliae and O. speciosissima (Coleoptera, Chrysomelidae) sequester in their elytral and pronotal defensive secretions pyrrolizidine alkaloids (PAs) as Noxides (PA N-oxides). The PA N-oxide patterns found in the beetles and their host plants were evaluated qualitatively and quantitatively by capillary gas chromatography/mass spectrometry (GC-MS). Of the three host plants...