Contact:
CENOLI
Université libre de Bruxelles, CP 231
Bd. du Triomphe, B-1050 Bruxelles
E-mail: etoffin [at] ulb.ac.be
Tel: 02 650 57 70 (from abroad +32 2 650 57 70)
Fax: 02 650 59 87 (from abroad +32 2 650 59 87)
orcid.org/0000-0002-5768-6803
Interests:
Main focus:
COMING SOON…
Publications:
2018
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| 6. | Toffin, Etienne; Gabriel, Edith; Louis, Marceau; Deneubourg, Jean-Louis; Grégoire, Jean-Claude Colonization of weakened trees by mass-attacking bark beetles: no penalty for pioneers, scattered initial distributions and final regular patterns (Journal Article) In: Royal Society Open Science, vol. 5, no. 1, 2018. @article{Toffin2018Colonization-of,
title = {Colonization of weakened trees by mass-attacking bark beetles: no penalty for pioneers, scattered initial distributions and final regular patterns},
author = {Etienne Toffin and Edith Gabriel and Marceau Louis and Jean-Louis Deneubourg and Jean-Claude Gr\'{e}goire},
url = {http://rsos.royalsocietypublishing.org/content/5/1/170454},
doi = {10.1098/rsos.170454},
year = {2018},
date = {2018-01-01},
journal = {Royal Society Open Science},
volume = {5},
number = {1},
publisher = {The Royal Society},
abstract = {Bark beetles use aggregation pheromones to promote group foraging, thus increasing the chances of an individual to find a host and, when relevant, to overwhelm the defences of healthy trees. When a male beetle finds a suitable host, it releases pheromones that attract potential mates as well as other textquoteleftspyingtextquoteright males, which result in aggregations on the new host. To date, most studies have been concerned with the use of aggregation pheromones by bark beetles to overcome the defences of living, well-protected trees. How insects behave when facing undefended or poorly defended hosts remains largely unknown. The spatio-temporal pattern of resource colonization by the European eight-toothed spruce bark beetle, Ips typographus, was quantified when weakly defended hosts (fallen trees) were attacked. In many of the replicates, colonization began with the insects rapidly scattering over the available surface and then randomly filling the gaps until a regular distribution was established, which resulted in a constant decrease in nearest-neighbour distances to a minimum below which attacks were not initiated. The scattered distribution of the first attacks suggested that the trees were only weakly defended. A minimal theoretical distance of 2.5 cm to the earlier settlers (corresponding to a density of 3.13 attacks dm-2) was calculated, but the attack density always remained lower, between 0.4 and 1.2 holes dm-2, according to our observations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Bark beetles use aggregation pheromones to promote group foraging, thus increasing the chances of an individual to find a host and, when relevant, to overwhelm the defences of healthy trees. When a male beetle finds a suitable host, it releases pheromones that attract potential mates as well as other textquoteleftspyingtextquoteright males, which result in aggregations on the new host. To date, most studies have been concerned with the use of aggregation pheromones by bark beetles to overcome the defences of living, well-protected trees. How insects behave when facing undefended or poorly defended hosts remains largely unknown. The spatio-temporal pattern of resource colonization by the European eight-toothed spruce bark beetle, Ips typographus, was quantified when weakly defended hosts (fallen trees) were attacked. In many of the replicates, colonization began with the insects rapidly scattering over the available surface and then randomly filling the gaps until a regular distribution was established, which resulted in a constant decrease in nearest-neighbour distances to a minimum below which attacks were not initiated. The scattered distribution of the first attacks suggested that the trees were only weakly defended. A minimal theoretical distance of 2.5 cm to the earlier settlers (corresponding to a density of 3.13 attacks dm-2) was calculated, but the attack density always remained lower, between 0.4 and 1.2 holes dm-2, according to our observations. |
2017
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| 5. | Bologna, Audrey; Toffin, Etienne; Detrain, Claire; Campo, Alexandre An automated method for large-scale monitoring of seed dispersal by ants (Journal Article) In: Scientific Reports, vol. 7, pp. 40143, 2017, ISSN: 2045-2322. @article{Bologna2017An-automated-me,
title = {An automated method for large-scale monitoring of seed dispersal by ants},
author = {Audrey Bologna and Etienne Toffin and Claire Detrain and Alexandre Campo},
url = {http://dx.doi.org/10.1038/srep40143},
doi = {10.1038/srep40143},
issn = {2045-2322},
year = {2017},
date = {2017-01-01},
journal = {Scientific Reports},
volume = {7},
pages = {40143},
publisher = {Springer Nature},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
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2016
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| 4. | Louis, Marceau; Toffin, Etienne; Grégoire, Jean-Claude; Deneubourg, Jean-Louis Modelling collective foraging in endemic bark beetle populations (Journal Article) In: Ecological Modelling, vol. 337, pp. 188 - 199, 2016, ISSN: 0304-3800. @article{Louis2016Modelling-colle,
title = {Modelling collective foraging in endemic bark beetle populations},
author = {Marceau Louis and Etienne Toffin and Jean-Claude Gr\'{e}goire and Jean-Louis Deneubourg},
url = {http://www.sciencedirect.com/science/article/pii/S0304380016302502},
doi = {http://dx.doi.org/10.1016/j.ecolmodel.2016.07.008},
issn = {0304-3800},
year = {2016},
date = {2016-01-01},
journal = {Ecological Modelling},
volume = {337},
pages = {188 - 199},
abstract = {Abstract Tree-killing bark beetles are widely studied at epidemic population densities because of their significant impacts on forests. At endemic levels, these species are restricted to poorly defended resources, such as wind-felled, lightning-struck, or suppressed trees. It is poorly understood how these scattered and unpredictable resources are discovered and exploited. In this prospect, the collective foraging shown by most bark beetles, in the form of independent searching by individual beetles combined with mutual attention to each other's chemical signals, represents an efficient strategy to increase the probability to discover the resources. In order to explore the role of host distribution and collective foraging on the discovery of and settlement on wind-felled trees by bark beetles at endemic population densities, we developed a spatially explicit foraging model for the major forest pest in Europe, Ips typographus. The model is based on the diffusion of the beetles, the landing of pioneers on wind-felled trees realistically distributed based on field observations in southern Belgium, and the response of flying beetles to pheromones emitted by these pioneers. The results show that social foraging effectively increases the proportion of beetles that landed on wind-felled resources compared to solitary foragers. Furthermore, the model highlights the parameters that influenced the foraging strategy of I. typographus and that need narrower quantification in further experiments. Finally, in the frame of the tested parameters, the model highlights the existence of thresholds in the reproduction rate and in the size of the starting population under which populations collapse. If confirmed, this prediction would shed new light on the understanding of foraging at low, endemic population levels.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Abstract Tree-killing bark beetles are widely studied at epidemic population densities because of their significant impacts on forests. At endemic levels, these species are restricted to poorly defended resources, such as wind-felled, lightning-struck, or suppressed trees. It is poorly understood how these scattered and unpredictable resources are discovered and exploited. In this prospect, the collective foraging shown by most bark beetles, in the form of independent searching by individual beetles combined with mutual attention to each other's chemical signals, represents an efficient strategy to increase the probability to discover the resources. In order to explore the role of host distribution and collective foraging on the discovery of and settlement on wind-felled trees by bark beetles at endemic population densities, we developed a spatially explicit foraging model for the major forest pest in Europe, Ips typographus. The model is based on the diffusion of the beetles, the landing of pioneers on wind-felled trees realistically distributed based on field observations in southern Belgium, and the response of flying beetles to pheromones emitted by these pioneers. The results show that social foraging effectively increases the proportion of beetles that landed on wind-felled resources compared to solitary foragers. Furthermore, the model highlights the parameters that influenced the foraging strategy of I. typographus and that need narrower quantification in further experiments. Finally, in the frame of the tested parameters, the model highlights the existence of thresholds in the reproduction rate and in the size of the starting population under which populations collapse. If confirmed, this prediction would shed new light on the understanding of foraging at low, endemic population levels. |
2010
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| 3. | Toffin, Etienne; Kindekens, Jonathan; Deneubourg, Jean-Louis Excavated substrate modulates growth instability during nest building in ants (Journal Article) In: Proc Roy Soc Lond B, vol. 277, no. 1694, pp. 2617–2625, 2010. @article{Toffin2010Excavated-subst,
title = {Excavated substrate modulates growth instability during nest building in ants},
author = {Etienne Toffin and Jonathan Kindekens and Jean-Louis Deneubourg},
doi = {10.1098/rspb.2010.0176},
year = {2010},
date = {2010-09-01},
journal = {Proc Roy Soc Lond B},
volume = {277},
number = {1694},
pages = {2617--2625},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
2009
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| 2. | Toffin, Etienne; Paolo, David Di; Campo, Alexandre; Detrain, Claire; Deneubourg, Jean-Louis Shape transition during nest digging in ants (Journal Article) In: Proc Natl Acad Sci USA, vol. 106, no. 44, pp. 18616–18620, 2009. @article{Toffin2009Shape-transitio,
title = {Shape transition during nest digging in ants},
author = {Etienne Toffin and David Di Paolo and Alexandre Campo and Claire Detrain and Jean-Louis Deneubourg},
doi = {10.1073/pnas.0902685106},
year = {2009},
date = {2009-11-01},
journal = {Proc Natl Acad Sci USA},
volume = {106},
number = {44},
pages = {18616--18620},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
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2004
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| 1. | Bourg, Éric Le; Toffin, Etienne; Massé, Antoine Male emphDrosophila melanogaster flies exposed to hypergravity at young age are protected against a non-lethal heat shock at middle age but not against behavioral impairments due to this shock (Journal Article) In: Biogerontology, vol. 5, no. 6, pp. 431–443, 2004. @article{Le-Bourg2004Male-emphDrosop,
title = {Male emphDrosophila melanogaster flies exposed to hypergravity at young age are protected against a non-lethal heat shock at middle age but not against behavioral impairments due to this shock},
author = {{\'{E}}ric Le Bourg and Etienne Toffin and Antoine Mass\'{e}},
doi = {10.1007/s10522-004-3200-9},
year = {2004},
date = {2004-11-01},
journal = {Biogerontology},
volume = {5},
number = {6},
pages = {431--443},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
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