V.2 Sensory Ecology of Arthropods Utilizing
Plant Infochemicals
Joop J.A. van Loon, Marcel Dicke
Laboratory of Entomology, Wageningen University, PO Box 8031, 6700 EH
Wageningen, The Netherlands
Abstract
Herbivorous and carnivorous arthropods are confronted with the highly diverse
chemistry that the plant world offers. The majority of herbivores displays very
specialized host-plant selection behavior which has its sensory basis in specialized
olfactory and gustatory cells that specifically respond to plant taxon-specific substances. The production of volatile compounds by plants is prone to variation
caused by a range of abiotic and biotic factors. Predators and parasitoids, acting as
the major natural enemies of herbivores, are likewise confronted with variability in
food-related volatile stimuli. Rather than utilizing cues directly emanating from
their food, they predominantly rely on plant-produced cues to locate prey or host
from a distance. Plants respond to damage by herbivores by changes in composition of the volatile blend released. These herbivore-induced plant volatiles are
used by carnivores to increase the efficiency of their foraging behavior. Although
their chemosensory ecology is largely unexplored, recent studies suggest that also
carnivorous arthropods possess chemoreceptors that are sensitive to herbivoreinduced plant volatiles. Analyzing the degree of chemosensory specificity and
plasticity in carnivorous arthropods in the context of their foraging behavior poses
an appealing challenge for research in sensory ecology.
Key words Insect-plant interactions, olfaction, searching mechanisms, herbivoreinduced synomones
1 Introduction
1.1 Dietary Specialization in Arthropods
Interactions between plants and arthropods are fruitfully studied under the
perspective of sensory ecology as it has been revealed that arthropods make
extensive use of their sensory systems to find plants and plant-feeding arthropod
hosts and prey. Arthropods fulfill vital roles in food webs of most terrestrial
ecosystems. Together with higher plants they constitute the majority of species
described (more than a million known species; Wilson 1992). For arthropod
communities inhabiting trees, about 25% of the species are herbivores, 25% are
Plant Infochemicals
Joop J.A. van Loon, Marcel Dicke
Laboratory of Entomology, Wageningen University, PO Box 8031, 6700 EH
Wageningen, The Netherlands
Abstract
Herbivorous and carnivorous arthropods are confronted with the highly diverse
chemistry that the plant world offers. The majority of herbivores displays very
specialized host-plant selection behavior which has its sensory basis in specialized
olfactory and gustatory cells that specifically respond to plant taxon-specific substances. The production of volatile compounds by plants is prone to variation
caused by a range of abiotic and biotic factors. Predators and parasitoids, acting as
the major natural enemies of herbivores, are likewise confronted with variability in
food-related volatile stimuli. Rather than utilizing cues directly emanating from
their food, they predominantly rely on plant-produced cues to locate prey or host
from a distance. Plants respond to damage by herbivores by changes in composition of the volatile blend released. These herbivore-induced plant volatiles are
used by carnivores to increase the efficiency of their foraging behavior. Although
their chemosensory ecology is largely unexplored, recent studies suggest that also
carnivorous arthropods possess chemoreceptors that are sensitive to herbivoreinduced plant volatiles. Analyzing the degree of chemosensory specificity and
plasticity in carnivorous arthropods in the context of their foraging behavior poses
an appealing challenge for research in sensory ecology.
Key words Insect-plant interactions, olfaction, searching mechanisms, herbivoreinduced synomones
1 Introduction
1.1 Dietary Specialization in Arthropods
Interactions between plants and arthropods are fruitfully studied under the
perspective of sensory ecology as it has been revealed that arthropods make
extensive use of their sensory systems to find plants and plant-feeding arthropod
hosts and prey. Arthropods fulfill vital roles in food webs of most terrestrial
ecosystems. Together with higher plants they constitute the majority of species
described (more than a million known species; Wilson 1992). For arthropod
communities inhabiting trees, about 25% of the species are herbivores, 25% are