Co-localization of insect olfactory sensory cells improves the discrimination of closely separated odour sources
Author
Summary, in English
1. The sense of smell is crucial for fitness of most animals, enabling them to find mates, food
and egg laying sites and to stay away from danger. Hence, odour molecules are detected by
sensitive and specific olfactory sensory neurons (OSNs). In insects, the OSNs are stereotypically
grouped into olfactory sensilla located mainly on the antennae. The functional significance
of this co-localization principle is poorly understood, but it has been hypothesized that
it allows for coincidence detection of odour filaments, improving discrimination of closely
separated odour sources.
2. Using an insect in its natural environment, we conducted the first experimental test of the
hypothesis. We manipulated the distance between odour sources of an attractive pheromone
and either of two host-derived attraction antagonists (1,8-cineole and verbenone) and investigated
the effect on trap catches of the bark beetle, Ips typographus (Coleoptera). 1,8-Cineole is
detected by an OSN co-localized with an OSN for one of the pheromone components, while
verbenone is detected by OSNs in other sensilla, not co-localized with pheromone OSNs.
3. Consistent with the hypothesis, trap catch increased with distance between odour sources
more for 1,8-cineole than for verbenone. The strongest effect was found among the males, that
is the sex that first locates and attacks the host tree.
4. Our data from the beetle provide, for the first time, direct experimental support for the
hypothesis that co-localization of OSNs in sensilla improves the discrimination of closely separated
odour sources. Thus, selection for improved odour source discrimination could well be
one of the factors explaining the strict co-localization of OSNs that is seen across the Insecta
class.
and egg laying sites and to stay away from danger. Hence, odour molecules are detected by
sensitive and specific olfactory sensory neurons (OSNs). In insects, the OSNs are stereotypically
grouped into olfactory sensilla located mainly on the antennae. The functional significance
of this co-localization principle is poorly understood, but it has been hypothesized that
it allows for coincidence detection of odour filaments, improving discrimination of closely
separated odour sources.
2. Using an insect in its natural environment, we conducted the first experimental test of the
hypothesis. We manipulated the distance between odour sources of an attractive pheromone
and either of two host-derived attraction antagonists (1,8-cineole and verbenone) and investigated
the effect on trap catches of the bark beetle, Ips typographus (Coleoptera). 1,8-Cineole is
detected by an OSN co-localized with an OSN for one of the pheromone components, while
verbenone is detected by OSNs in other sensilla, not co-localized with pheromone OSNs.
3. Consistent with the hypothesis, trap catch increased with distance between odour sources
more for 1,8-cineole than for verbenone. The strongest effect was found among the males, that
is the sex that first locates and attacks the host tree.
4. Our data from the beetle provide, for the first time, direct experimental support for the
hypothesis that co-localization of OSNs in sensilla improves the discrimination of closely separated
odour sources. Thus, selection for improved odour source discrimination could well be
one of the factors explaining the strict co-localization of OSNs that is seen across the Insecta
class.
Department/s
Publishing year
2014
Language
English
Pages
1216-1223
Publication/Series
Functional Ecology
Volume
28
Issue
5
Document type
Journal article
Publisher
Wiley-Blackwell
Topic
- Zoology
Keywords
- Coleoptera
- Curculionidae
- Ips typographus
- Monoterpene
- Odour source spacing
- Olfactory receptor neuron
- Olfactory sensory neuron
- Pheromone antagonist
Status
Published
Research group
- Pheromone Group
ISBN/ISSN/Other
- ISSN: 1365-2435