Dr. Joanneke H. Reudler Talsma
Department of Biological and Environmental Science
e-mail: Talsma.reudler(a)bytl.jyu.fi
tel. +358 (0)14 260 2244
fax +358 (0)14 260 2321
Project
Host plant chemistry,
especially allelochemistry, is known to play an important role in mediating the
interaction of herbivores with their predators and parasitoids. One mechanism
for this mediation is herbivore sequestration of host plant allelochemicals,
which serve as a defence against natural enemies. Aposematic species even
advertise to predators their unprofitability with conspicuous warning colours.
Theoretical approaches to prey defence have traditionally dealt only with the
education and survival of predators but ignored other selection pressures such
as the cost of sequestering or other constraints caused by the herbivore diet.
Moreover, most prey animals are target of multiple enemies and thus, a
high-quality defence against predators does not necessarily guarantee defence
against parasitoids and diseases. In this project I will examine how the
sequestration of plant allelochemicals affects the defence of specialist and
generalist herbivores against multiple enemies (predator (warning signal size),
parasitoids (encapsulation ability) and diseases (survival)).
A
model system of plants containing iridoid glycosides, three different
caterpillars (non-sequestering generalist, aposematic sequestering generalist
and a sequestering specialist), their parasitoids and a generalist bacterial
pathogen, will be used to investigate the roles of sequestered plant
allelochemicals in herbivore-parasitoid-disease interactions. Three experiments
will be performed. In the first I will look at the sequestration and excretion
of the plant chemicals in the herbivore diets, in the different developmental
stages of the caterpillars and their parasitoids. In the second experiment I
will look at the effect of varying iridoid concentration in the herbivore diet
on naïve and specific encapsulation ability of the different caterpillars
and look at the effect of multiple infections (parasitoid and disease). In the third experiment I will look at
the parasitoid preference in the field and in dual choice experiments, with
respect to the herbivore diet and the warning signal size of the aposematic
larvae.
These
experiments will increase our knowledge about the importance of plant chemicals
on higher trophic levels. A lot of research has already been done with
predator-prey interactions, but information about one of the main natural
enemies of herbivores, parasitoids, is lacking. With this project I investigate
how important plant chemicals are in the defence of herbivores against
parasitoids, depending on the amount of plant chemicals they eat, their ability
to sequestrate these chemicals, and their effects under laboratory conditions,
but also in the field.
Publications
Refereed Journals
C. Lindstedt, J. H. Reudler Talsma, E. Ihalainen, J. Mappes, L.
Lindström. 2009
Diet quality affects warning coloration indirectly: excretion costs in a
generalist herbivore.
Evolution, 64-1: 68-78
J.H.Reudler
Talsma, Torri, K. van Nouhuys, S. 2008 PDF
Host plant use by the Heath fritillary butterfly, Melitaea athalia:
plant habitat, species and chemistry.
Arthropod-Plant Interactions, 2: 63-75
J.H.
Reudler Talsma, Biere, A., Harvey, J. A., van
Nouhuys, S. 2008 PDF
Oviposition cues for a specialist butterfly: plant chemistry and size.
Journal of Chemical Ecology, 34: 2102-1212
J.H. Reudler Talsma, J.A. Elzinga, J.A. Harvey, A.
Biere 2007 (link)
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
M.V. Schneider, G. Driessen, L.W. Beukeboom, R. Boll, K. van Eunen, A. Selzner, J.H.
Talsma, L. Lapchin 2003 (link)
Gene flow between arrhenotokous and thelytokous populations of Venturia canescens (Hymenoptera). Heredity 90 (3): 260-267
Other publications
J.H. Reudler Talsma 2007 PDF
Costs and benefits of iridoids glycosides in multitrophic systems. PhD
thesis.
In preparation
J.H. Reudler Talsma, S.
C. Honders, H. Turin and A. Biere
Trade-offs between chemical defence and regrowth capacity in Plantago lanceolata. in prep
J.H. Reudler Talsma, A. Biere, J. A. Harvey, S. van Nouhuys
Performance of
specialist and generalist herbivores using chemically defended Plantago lanceolata as a host plant. in
prep