Species influence each other both directly, and through intermediaries. For instance the effects of host plant defense can cascade through the food chain through herbivores, diseaseas and parasitoids. Because plant qualities differ spatially and temporally they can cause higher tropic level population sizes to vary, and community structure to be spatially heterogeneous. This is summarized in:
van Nouhuys, S. & Hanski, I. 2002. Multitrophic interactions in space: metacommunity dynamics in fragmented landscapes. In Multitrophic level interactions (T. Tscharntke & B. A. Hawkins eds.) Cambridge University Press. pp. 124-147
We study direct and indirect interactions among species, mostly using:
Plants: Plantago lanceolata & Veronica spicata
Herbivores: Melitaea cinxia & Melitaea athalia
Parasitoids: Cotesia melitaearum, Hyposoter horticola, Pteromalus apum
Hyperparasitoids: Gelis agilis & Mesochorus stigmaticus
Iridoid glycosides are secondary metabolites produced by several plant families, including Plantaginaceae. They are considered as chemical defense against generalist herbivores. We study the roles of iridoid glycosides for the insects associated with the two host plants Plantago lanceolata and Veronica spicata. Most of the species we study have narrow host ranges, and in fact benefit from iridoid glycosides. We have studied the roles of these chemicals for the herbivore, parasitoids and hyperparasitoids.
Reudler Talsma, J., Biere, A., Harvey, J. A., van Nouhuys, S.2011 Oviposition cues for a specialist butterfly: plant chemistry and size. Journal of chemical Ecology, 37: 765-778
Reudler Talsma, J., Torri, K. van Nouhuys, S. 2008 Host plant use by the Heath fritillary butterfly, Melitaea athalia : plant habitat, species and chemistry. Arthropod-Plant Interactions, 2: 63-75
Saastamoinen, M., van Nouhuys, S., Nieminen, M., O'Hara, B., Suomi, J. 2007. Development and survival of a specialist herbivore, Melitaea cinxia, on host plants producing high and low concentrations of iridoid glycosides. Annales Zoologici Fennici, 44: 70-80
van Nouhuys, S., M.C. Singer, M. Nieminen. 2003. Spatial and temporal patterns of caterpillar performance and the suitability of two host plant species. Ecological Entomology, 28: 193-202
Kaiser, L., Ode, P., van Nouhuys, S., Calatayud, P., Colazza, S., Cortesero, A., Thiel, A., van Baaren, J. 2016. The plant as a habitat for entomophagous insects in Plant-Insect interations (eds. Sauvion, N., Calatayud, P., and Thiery, D.). Advances in Botanical Research Volume 81. http://dx.doi.org/10.1016/bs.abr.2016.09.006
Reudler, J. H., Biere, A., Harvey, J. A., van Nouhuys, S. 2011. Differential performance of a specialist and two generalist herbivores and their parasitoids on Plantago lanceolata. Journal of Chemical Ecology, 37: 765-778
Harvey, J.A., van Nouhuys, S., Biere, A. 2005. Effects of quantitative variation in allelochemicals in Plantago lanceolata on development of a generalist and a specialist herbivore and their endoparasitoids.
Nieminen, M., J. Suomi, S. van Nouhuys, P. Sauri, M. Riekkola. 2003. Effect of iridoid glycoside content on oviposition host plant and parasitism in a specialist herbivore. Journal of Chemical Ecology, 29: 823-844
van Nouhuys, S., Reudler, J. H., Biere, A., Harvey, J. A. 2012. Performance of secondary parasitoids on chemically defended and undefended hosts. Basic and Applied Ecology, 13: 241-249
Plants emit volatile organic chemicals that can be used by foragingherbivores and parasitoids The concentrations and identities of these odors change in response to herbivory and even oviposition by herbivores. We are interested in the existence and reliability of these odors as signals for parasitoid wasps. Our current work, mostly being done by Joanneke Reudler Talsma is on (1) how odors of the host plants Veronica spicata and Plantago lanceolata change with herbivoroy and oviposition, (2) how herbivore-specific these changes are and, (3) the specificity of response by parasitoid wasps.
Pinto-Zevallos, D. M., H. Hellén, et al. 2013. Induced defenses of Veronica spicata: Variability in herbivore-induced volatile organic compounds. Phytochemistry Letters 6(4): 653-656.
Castelo, M. K., van Nouhuy, S., Corley, J. C. 2010. Olfactory attraction of the larval parasitoid, Hyposoter horticola, to plants infested with eggs of the host butterfly, Melitaea cinxia. Journal of insect Science, Vol. 10, article 53
Not all interactions (direct and indirect) in a herbivore based food chain are directly related to plant defense.
Rasmussen, P. U., Amin, T., Bennett, A. E., Karlsson Green, K., Timonen, S., van Nouhuys, S., Tack, A. J. M. 2017. Plant and insect genetic variation mediate the impact of arbuscular mycorrhizal fungi on a natural plant-herbivore interaction.
Ecological Entomology, in press.
van Nouhuys, S. Kohonen, M. Duplouy, A. 2016 Wolbachia increases the susceptibility of a parasitoid wasp to hyperparasitism. Journal of Experimental Biology, 219 2984-2990
Summary feature in Inside JEB
Duplouy, A., Couchoux, C., Hanski, I., van Nouhuys, S. 2015 Wolbachia infection in a natural parasitoid wasp population. PLOS One, 10(8): e0134843. doi:10.1371/journal.pone.0134843
Saastamoinen, M., Hirai, N., van Nouhuys, S. 2013. Direct and trans-generational responses to food deprivation during development in the Glanville fritillary butterfly.
Oecologia, 171: 93-104
van Nouhuys, S. and Laine, A-L. 2008 Population dynamics and sex ratio of a parasitoid altered by fungal infected diet of host butterfly. Proceedings of the Royal Society B , 275: 377-385
van Nouhuys, S. & I. Hanski. 1999. Host diet affects extinctions and colonizations in a parasitoid metapopulation. Journal of Animal Ecology, 68: 1248-125