Thesis subject

Nematodes on the run – Effects of insect herbivore-induced plant responses on belowground communities

Insects and nematodes are among the most abundant groups of plant feeding organisms on either side of above-belowground interfaces.

Both communities contain a tremendous diversity of herbivore species with a variety of feeding behaviour, and non-herbivore species such as carnivores, pollinators, bacterial and fungal feeders. Herbivores often elicit systemic changes in various plant traits when they attack the plant, and this can affect many other community members. For example, indirect herbivore-herbivore competition due to changes in plant quality, or carnivore attraction due to the emission of herbivore-induced plant volatiles are well studied.

It is becoming more clear that these interactions can engage members of very different communities and with this aboveground – belowground interactions between nematodes and insect herbivores have received some attention. It is still unknown however how common these interactions are, if they are limited to one-on-one species interactions or can affect whole communities, and if different initiator species can evoke different reactions in the same responder. To explore this further, this master thesis topic will investigate whether insect herbivore-induced plant responses will affect the nematode community under field conditions. Insect herbivores span different feeding guilds (e.g. chewing and sucking) which elicit different herbivore-induced plant responses and we are interested if these differ in their effect on the nematode community.