2014-08-08 13.26.00                Dr. Joanneke H. Reudler Talsma


                Department of Biological and Environmental Science
            P.O. Box 35, FIN-40014
            University of Jyväskylä, Finland
            e-mail: talsma.reudler(a)jyu.fi or jhtalsma@hotmail.com
            tel. +358 (0)44 946 1655





When do I smell most attractive?


Plant volatile organic compounds (VOCs) play an important role in plant adaptations to their environment, serving as infochemicals in multitrophic interactions. Parasitoids, insects whose larvae develop by feeding on the bodies of other arthropods, find their hosts by responding to cues in their surroundings. A good cue gives reliable information about the host and is detectable over an appropriate distance. Most cues are volatile odours derived from the host or from what the host is feeding on as a result of injury or as a reaction to herbivore saliva.

Herbivore-induced VOCs play an important role in attracting natural enemies of insect herbivores. These volatiles have been shown to be plant and herbivore species specific and to change in response to different feeding stages of an herbivore.

The character of VOCs can also be altered by belowground interactions such as root herbivores or associations with arbuscular mycorrhizal fungi (AMF). Arbuscular mycorrhizal fungi form a symbiotic association with plants, helping roots to capture nutrients from the soil. In return AMF take up products of the host’s photosynthesis. About 80% of all terrestrial plants form associations with AMF. A number of studies have reported the effects of AMF on plant defensive compounds such as volatile terpenoids, essential oils and glucosinolates.

Finally, abiotic factors can influence the VOC blend. Elevating temperature often increases the emission rate of VOCs while drought and elevating atmospheric CO2 may have the opposite effect. Our knowledge of the signalling role of VOCs in natural multitrophic systems is poor and the possible role of current climate change on the signalling between trophic levels by VOCs in these systems is totally unexplored.




In my research I focus on the butterfly Melitaea cinxia, its host plants Plantago lanceolata L. and Veronica spicata L. (Plantaginaceae) and two parasitoids in the research system. This butterfly is part of an ecologically and evolutionarily well-studied group of butterflies and is an important model system for metapopulation research and the study of populations in a fragmented landscape. Melitaea cinxia has declined in most of Europe and is even extinct in some countries, however it occurs together with its congener M. athlaia on the Åland Island, located in southwest Finland. Melitaea cinxia supports a community of eleven parasitoid species on the Åland islands. There are two specialist parasitoid wasps that interact most strongly with M. cinxia. Cotesia melitaearum (Wilkinson, 1937) (Braconidae: Microgastrinae) is a gregarious koinobiont endoparasitoid and has three generations per host generations (year). Its only host species is M. cinxia.

The other specialist parasitoid is Hyposoter horitcola (Gravenhorst, 1829) (Ichneumonidae: Campopleginae), a large and long-lived solitary koinobiont endoparasitoid. Its only certain host is M. cinxia. It can disperse extremely well, even to isolated and newly colonised local host populations. The wasp has an extremely short window of opportunity for parasitism (few hours) because the female can only lay eggs in fully formed larvae which have not yet hatched from the eggs. This wasp parasitizes about one third of all larvae in a host egg cluster, and is found in virtually all local host populations in Åland.



Research questions

·         Does larval feeding of the two specialist herbivore species (M. cinxia and M. athalia) induce different VOC blends (quantitative and/or qualitative) in their two common host plants?

·         Does the specialist parasitoid C. melitaearum have a preference for a specific induced volatile blend induced by M. cinxia (its host) over M. athalia?

·         Does the association with AMF influence the emitted VOC blend? Does this influence the attraction of the parasitoids? What is the effect of simultaneous association of different AMF species with one plant?

·         Does growing at elevated temperature, CO2 or O3 atmosphere affect the VOCs of intact and/or M. cinxia induced plants? Do they cause different changes in the VOC blend for the two host plants? Can the oxidation of plant emitted VOCs at elevated ozone atmospheres disrupt the chemical communication between these plant species and parasitoids?




Dr. Saskya van Nouhuys (University of Helsinki)

Prof. Jarmo Holopainen  and James Blande (University of Eastern Finland, Kuopio)

Dr. Arjen Biere (NIOO-KNAW, Wageningen, the Netherlands)





Refereed Journals

Between brackets the number of citations of the article in Google Scholar (S:), H-index  8.


Reudler, J.H., Lindstedt, C., Pakkanen, H., Lehtinen, I. and J. Mappes 2015 (link)

Costs and benefits of plant allelochemicals in herbivore diet in a multi enemy world. Oecologia 179:1147–1158

DOI 10.1007/s00442-015-3425-0


Reudler J.H. and Elzinga, J.A. 2015 (link)

Photoperiod-induced geographic variation in plant defence chemistry. Journal of Chemical Ecology 41:139-148

DOI 10.1007/s10886-015-0550-5


Reudler, J.H., Honders, S.C. Turin, H. and Biere, A. 2013 (link) (S:2)

Trade-offs between chemical defence and regrowth capacity in Plantago lanceolata. Evolutionary Ecology 27:883-898

DOI 10.1007/s10682-012-9609-8


van Nouhuys, S.,  Reudler, J.H.,  Biere, A. and Harvey, J.A.  2012 (link) (S:3)

Performance of secondary parasitoids on chemically defended and undefended hosts.  Basic and Applied Ecology 13:241-249

DOI 10.1016/j.baae.2012.03.006


Laurentz, M. Reudler, J.H., Mappes, J., Friman, V., Ikonen, S. and Lindstedt, C. 2012 (link) (S:12)

Diet quality can play a critical role in defense efficacy against parasitoids and pathogens in the Glanville Fritallary (Melitaea cinxia)

Journal of Chemical Ecology 1: 116-125

DOI 10.1007/s10886-012-0066-1


Nokelainen, O., Hegna, R.,Reudler, J.H., Lindstedt, C. and Mappes, J. 2012 (link) (S:43)

Trade-off between warning signal efficacy and mating success in the wood tiger moth.  Proc. R. Soc. B 279: 257–265

DOI 10.1098/rspb.2011.0880


Reudler, J. H., Biere, A., Harvey, J. A., van Nouhuys, S. 2011 PDF (S:18)
Differential performance of a specialist and two generalist herbivores and their parasitoids on Plantago lanceolata. Journal of Chemical Ecology 37:765-778 

DOI 10.1007/s10886-011-9983-7


Lindstedt, C., Reudler Talsma, J. H., Ihalainen, E., Lindström, L. & Mappes, J. 2010 (link) (S:29)

Diet quality affects warning coloration indirectly: excretion costs in a generalist herbivore. Evolution 64: 68-78

DOI: 10.1111/j.1558-5646.2009.00796.x


Reudler Talsma, J.H., Torri, K. van Nouhuys, S. 2008 PDF (S:14)
Host plant use by the Heath fritillary butterfly, Melitaea athalia: plant habitat, species and chemistry.  Arthropod-Plant Interactions 2: 63-75

DOI 10.1007/s11829-008-9039-2


Reudler Talsma, J.H., Biere, A., Harvey, J. A., van Nouhuys, S. 2008 PDF (S:39)
Oviposition cues for a specialist butterfly: plant chemistry and size. Journal of Chemical Ecology 34: 2102-1212

DOI 10.1007/s10886-008-9519-y


Reudler Talsma, J.H., J.A. Elzinga, J.A. Harvey, A. Biere 2007 (link) (S:10)

Optimum and maximum host size at parasitism for the endoparasitoid Hyposoter didymator (Hymenoptera: Ichneumonidae) differ greatly between two host species.

Environmental Entomology 36 (5): 1048-1053

DOI 10.1603/0046-225X


Schneider; M.V., Driessen, G., Beukeboom, L.W.,  Boll, R., van Eunen, K., Selzner, A., Talsma, J.H. and Lapchin, L.  2003 (link) (S.25)

Gene flow between arrhenotokous and thelytokous populations of Venturia canescens (Hymenoptera). Heredity 90 (3): 260-267

DOI 10.1038/sj.hdy.6800245



Publications intended for the general public

Nokelainen, O., Hegna, R. Reudler, J.H., Lindstedt, C., Mappes, J. 2011. Trading off danger for girls. Science news, Society for the Science and the Public

Beintema, N. 2009. Een plant moet keuzes maken. NVOX  January 2009 14-15 (link)




Reudler Talsma, J.H. 2007 PDF (S:7)

Costs and benefits of iridoids glycosides in multitrophic systems. PhD thesis. Wageningen University, the Netherlands


Reudler Talsma, J.H.  and van der Lindern M. 2002

Profit, People, Planet: implementation of sustainable development in an education task. Master thesis, Environmental Service Midden-Holland Gouda, the Netherlands


Reudler Talsma, J.H. 2001

Is occasional sex the beginning of a dead end? Master thesis, Leiden University, the Netherlands


Reudler Talsma, J.H. 2000

De weg van de minste weerstand. (The road of least resistance: the resistance of the landscape against the dispersion of ground-dwelling species). Master thesis, Alterra WAgeingen, the Netherlands



Submitted/in review



In preparation

Reudler J.H. and S. van Nouhuys

The effect of host plant use on the parasitation rate of Pteromalus apum.


Reudler J.H., Biere, A., Harvey J.A. and van Nouhuys, S.

Iridoid glycoside sequestration up to the fourth trophic level


Reudler J.H., Mofikoya, D., Holopainen, J and van Nouhuys, S.

Difference in herbivore induced VOC of Plantago lanceolata and Veronica spicata