Université de Neuchâtel

From Asia to Europe : evaluation of parasitoids for the biological control of the invasive fruit pest "Drosophila suzukii"

Girod, Pierre ; Turlings, Ted (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2018.

Agricultural processes are constantly improved to improve crop yields. However, 40% of crop productions are currently lost to pests each year. Insect pests are one of the main factors of these losses and their management is one of the top priorities that researchers are facing worldwide. An important part of these losses are caused by pest with alien origins. Globalization and climate change...

Université de Neuchâtel

Factors that determine the effectiveness of entomopathogenic nematodes in combination with other beneficial soil organisms to control root herbivores

Chiriboga Morales, Xavier ; Turlings, Ted (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2017.

Belowground ecosystems are inhabited not only by organisms that represent a threat to plants (e.g. root herbivores and pathogens), but also by organisms that provide protection to these antagonists (e.g. entomopathogenic nematodes, mychorrizal fungi and root associated bacteria). Herbivore-induced root volatiles, such as the sesquiterpene E-(β)-caryophyllene, are an indirect defense in...

Université de Neuchâtel

The mate-seeking strategies of four braconid parasitoids (Hymenoptera: Braconidae)

Xu, Hao ; Turlings, Ted (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2017.

Parasitic wasps are widely used as biological control agents. To optimize their applications in agriculture, we need to understand how they locate hosts and mate. Parasitic wasps have about 50,000 described species, but less than 30 species have so far been tested in terms of their use of pheromones. In this thesis, I used a combination of bioassays, chemical analyses, and electrophysiological...

Université de Neuchâtel

Pyrrolizidine alkaloids : occurrence in bee products and impact on Honeybees ("Apis mellifera" L.)

Lucchetti, Matteo Angelo ; Turlings, Ted (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2017.

Pyrrolizidine alkaloids (PAs) are toxic plant secondary metabolites produced as defense against herbivores by a wide variety of plants, mainly of the Boraginaceae, Asteraceae and Fabaceae families. Consumption of products contaminated with PAs may lead to hepatotoxic, carcinogenic, genotoxic and teratogenic effects in animals and humans. PAs are mostly found in leaves, roots and seeds, and may...

Université de Neuchâtel

Enhancing the use of entomopathogenic nematodes for biological control of root pests : from field persistence to improved shelf-life

Jaffuel, Geoffrey ; Turlings, Ted (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2016.

Agriculture is evolving towards more sustainable strategies since the application of agrochemicals and physical management of the soil have severe environmental impact and deplete soil quality. The potential of using biocontrol agents to replace or in combination with pesticides has been investigated for several decades. Entomopathogenic nematodes (EPN) are very promising in this respect. EPN are...

Université de Neuchâtel

Tritrophic interactions on cultivated maize and its wild ancestor "teosinte"

De Lange, Elvira Simone ; Turlings, Ted (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2014.

Modern maize plants (Zea mays ssp. mays, Poaceae) are characterized by large cobs that contain juicy grains, although they have not always had these characteristics. Approximately 9000 years ago, maize was domesticated from teosinte (Z. mays ssp. parviglumis), its closest wild ancestor, which produces much less and much smaller seeds. Teosinte still grows in the wild...

Université de Neuchâtel

The role of indole in maize-herbivore interactions

Veyrat, Nathalie ; Turlings, Ted (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2014.

In order to counter herbivore attacks, plants have developed a multitude of defence strategies, including the release herbivore-induced plant volatiles (HIPVs). HIPVs can be used as foraging cues by natural enemies of the herbivores, including predators and parasitoids. In addition, they can also be exploited by herbivores themselves to localize their host plants. Some HIPVs even prime...

Université de Neuchâtel

Mites and endosymbionts : towards improved biological control

Zindel, Renate ; Turlings, Ted (Dir.) ; Aebi, Alexandre (Codir.)

Thèse de doctorat : Université de Neuchâtel, 2012.

The microbiome associated with arthropods is very diverse and may significantly influence the biology of biological biocontrol agents and arthropod pests. Some endosymbiont bacteria may even be used to achieve pest or disease vector biological control. The subclass Acari (mites and ticks) is very diverse in form, habitat and behaviour. Mites can be plant pests, parasites of domestic animals...

Université de Neuchâtel

Parasotoid communities and genetic structure : host plant does not matter

Jourdie, Violaine ; Turlings, Ted (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2008 ; Th. 2050.

Plant-insect interactions have long been studied and reveal intricate mechanisms. Plants are capable of defending themselves both directly by poisoning insect herbivores and indirectly by emitting volatile compounds that are used by the natural enemies to localize their host. In response, insects have evolved strategies to defeat plant defense mechanisms. Because insect pests are affected by...