Skip to content. | Skip to navigation

Personal tools

You are here: Home

Search results

RSS Subscribe to an always-updated RSS feed.

4370 items matching your search terms.
Filter the results.
Item type



































New items since



Sort by relevance · date (newest first) · alphabetically
Article Reference Site Fidelity of Formica rufa: Micro-Scaled and Persistent Despite Disturbance (Hymenoptera: Formicidae)
Long-term site fidelity or Ortstreue is an individual foraging strategy typical of ants exploiting stable and predictable food sources in space and time. Red wood ant workers (Formica s. str.) are central-place foragers feeding on honeydew secreted by stable aphid populations. In this field study, temporal site fidelity of Formica rufa honeydew tenders was investigated on a micro-scaled level for a period of time. Additionally, the effect of exchanging honeydew workers between two trees on site fidelity was examined. Site fidelity of the honeydew tenders was very high and they returned repeatedly to particular micro-sites (branches, set of leaves) on a tree. The transfer to a new feeding site apparently did not influence site fidelity as honeydew tenders mainly return to their initial tree. Small-scale site fidelity decreased with time and was not so rigid as larger-scale fidelity. We discuss how site fidelity on one hand and flexibility in foraging and recruiting on the other hand promote foraging efficiency of the colony.
Located in Library / RBINS Staff Publications
Article Reference Nematode communities of small pools in an agricultural landscape
Located in Library / RBINS Staff Publications
Article Reference Larval presence prediction through logistic regression: an early warning system against Mytilopsis leucophaeata biofouling
Mytilopsis leucophaeata is a biofouling bivalve causing major problems in the cooling water system of BASF, Antwerp NV, Belgium, a large water-using industrial facility. This study aimed to develop a statistical model to predict the response of M. leucophaeata larvae to environmental conditions in estuarine ecosystems. Multiple logistic regression, taking into account temporal autocorrelation, was applied on a large dataset allowing the prediction of the probability of occurrence of M. leucophaeata larvae at BASF NV as a response to the environmental variables. The final model made it possible to predict larval presence in the water column solely by monitoring water temperature. The results from subsampling indicated that the model was stable. The model was tested with 2005 data, demonstrating a 98\% precise prediction of the occurrence of M. leucophaeata larvae in the water column, with a sensitivity of 100\% and a specificity of 97\%, even though autumn 2005 was exceptionally warm, which led to an extended presence of the larvae.
Located in Library / RBINS Staff Publications
Article Reference Isolation and characterization of microsatellite loci in the dark bush cricket, Pholidoptera griseoaptera (Tettigoniidae)
Twelve novel polymorphic microsatellite loci are presented for the dark bush cricket, Pholidoptera griseoaptera. All loci are polymorphic, with up to 37 alleles per locus. These microsatellites will be useful tools for studying the influence of landscape structure and land use intensity in agricultural landscapes on genetic diversity within and among populations of P. griseoaptera.
Located in Library / RBINS Staff Publications
Article Reference Is the hairy groove in the gibbosus male morph of Oedothorax gibbosus (Blackwall 1841) a nuptial feeding device?
Oedothorax gibbosus (Blackwall 1841) (Erigoninae, Linyphiidae, Araneae) is a dwarf spider characterized by dimorphic males. There is a "gibbosus" male morph characterized by a hunch on the posterior third of the carapace, anterior to which is a hairy groove, and a "tuberosus" morph without these features. We observed several gustatorial courtship interactions by a gibbosus male morph and a conspecific female as well as a by a gibbosus male and a male of the closely related species, Oedothorax fuscus (Blackwall 1834). These interactions suggest that the hairy groove in the gibbosus male morph is a nuptial feeding device possibly under the influence of sexual selection. The interspecific interactions can possibly be interpreted as 'robbings' of the nuptial feeding. The interspecific interactions indicate that the cephalic structure of gibbosus probably does not function as a "lock and key" mechanism.
Located in Library / RBINS Staff Publications
Article Reference Hydrological regime and salinity alter the bioavailability of Cu and Zn in wetlands
In the context of the European Water Framework Directive, controlled flooding of lowlands is considered as a potential water management strategy to minimise the risk of flooding of inhabited areas. However, due to historical pollution and overbank sedimentation, metal levels are elevated in most wetlands, which can cause adverse effects on the ecosystem's dynamics. Additionally, salinity affects the bioavailability of metals present or imported into these systems. The effect of different flooding regimes and salinity exposure scenarios (fresh- and brackish water conditions) on Cu and Zn accumulation in the oligochaete Tubifex tubifex (Muller, 1774) was examined. Metal mobility was closely linked to redox potential, which is directly related to the prevalent hydrological regime. Flooded, and thus more reduced, conditions minimized the availability of metals, while oxidation of the substrates during a drier period was associated with a rapid increase of metal availability and accumulation in the oligochaetes. (C) 2009 Elsevier Ltd. All rights reserved.
Located in Library / RBINS Staff Publications
Article Reference Functional richness of local hoverfly communities (Diptera, Syrphidae) in response to land use across temperate Europe
Environmental change is not likely to act on biodiversity in a random manner, but rather according to species traits that affect assembly processes, thus, having potentially serious consequences on ecological functions. We investigated the effects of anthropogenic land use on functional richness of local hoverfly communities of 24 agricultural landscapes across temperate Europe. A multivariate ordination separated seven functional groups based on resource use, niche characteristics and response type. Intensive land use reduced functional richness, but each functional group responded in a unique way. Species richness of generalist groups was nearly unaffected. Local habitat quality mainly affected specialist groups, while land use affected intermediate groups of rather common species. We infer that high species richness within functional groups alone is no guarantee for maintaining functional richness. Thus, it is not species richness per se that improves insurance of functional diversity against environmental pressures but the degree of dissimilarity within each functional group.
Located in Library / RBINS Staff Publications
Article Reference Experimental exposure to cadmium affects metallothionein-like protein levels but not survival and growth in wolf spiders from polluted and reference populations
Both local adaptation and acclimation in tolerance mechanisms may allow populations to persist under metal pollution. However, both mechanisms are presumed to incur (energetic) costs and to trade-off with other life-history traits. To test this hypothesis, we exposed Pardosa saltans (Lycosidae) spiderlings originating from metal-polluted and unpolluted sites to a controlled cadmium (Cd) treatment, and compared contents of metal-binding metallothionein-like proteins (MTLPs), internal metal concentrations, and individual survival and growth rates with a reference treatment. While increased MTLP concentrations in offspring originating from both polluted and unpolluted populations upon exposure indicates a plastic tolerance mechanism, survival and growth rates remain largely unaffected, independent of the population of origin. However, MTLP and Cd concentrations were not significantly correlated. We suggest that MTLP production may be an important mechanism enabling P. saltans populations to persist in ecosystems polluted with heavy metals above a certain level. (C) 2010 Elsevier Ltd. All rights reserved.
Located in Library / RBINS Staff Publications
Article Reference Differentiation between two salt marsh beetle ecotypes: Evidence for ongoing speciation
The plausibility of trait divergence under divergent natural selection in the presence of gene flow in natural populations is a contentious issue in evolutionary research. Its importance lies in the fact that this process is thought to be one of the key triggers in ecological speciation in which a species splits into ecologically distinct forms when separate niches are occupied. in this study we demonstrate strong genetic divergence at the IDH1 locus between pond- and canal-inhabiting individuals of the salt marsh beetle Pogonus chalceus from the Guerande salt fields. Moreover, wing size, a trait that has a heritable basis in this species, was significantly larger in the pond populations, which is in concordance with the unstable nature of this habitat. The relationship between IDH1 allele frequencies and wing size variation was consistent with patterns seen across western European populations. By means of neutral allozymes and microsatellites we detected a small but significant degree of sexual isolation between ecotypes. We conclude that speciation is ongoing and that divergence reflects a balance between selection and gene flow.
Located in Library / RBINS Staff Publications
Article Reference Differences in geographic distribution and habitat of some cryptic species in the Pardosa lugubris group (Lycosidae, Araneae) in Belgium
The habitat and distribution of some closely related species of the P. lugubris s.l. group in Belgium are described to contribute to our understanding of the coexistence and speciation of these 'cryptic' species. With a few exceptions, P. lugubris has its main distribution in the lower part of Belgium where it occurs on sandy, nutrient poor soils. P. saltans occurs widely in Belgium except for in the Campine region where the species is totally absent. P. alacris was only found at three localities where limestone outcrops are present. The habitat of P. lugubris is pine and birch forests while in Fagus woodlands, only P. saltans was found. In Quercus forests, both species were found, often in mixed populations. A combination of micro- and macroclimatological features and habitat characteristics cause the differences in distribution of these species.
Located in Library / RBINS Staff Publications