Skip to content. | Skip to navigation

Personal tools

You are here: Home
1007 items matching your search terms.
Filter the results.
Item type



































New items since



Sort by relevance · date (newest first) · alphabetically
Article Reference Diversity of Ants and Termites of the Botanical Garden of the University of Lomé, Togo
Ants and termites are used as bioindicators in many ecosystems. Little knowledge is available about them in Togo, especially ants. This study aimed to find out how ants and termites could be used to assess the restoration of former agricultural land. These insect groups were sampled within six transects of 50 × 2 m2 (using pitfall traps, monoliths, baits for ants and hand sampling for termites) in two consecutive habitats: open area (grassland) and covered area (an artificial forest). Seventeen termite species and 43 ant species were collected. Seven ant species were specific to the covered area against four for the open area, while four unshared species of termite were found in the open area against three in the covered area. The presence of unshared species was linked to vegetation, as Trinervitermes (Holmgren, 1912), a grass feeding termite, was solely found in open area. Also, for some ant species like Cataulacus traegaordhi (Santschi, 1914), Crematogaster (Lund, 1831) species, Oecophylla longinoda (Latreille, 1802) and Tetraponera mocquerysi (Brown, 1960), all arboreal species, vegetation was a determining factor for their presence. The occurrence of these species together with Basidentitermes mactus (Sjöstedt, 1911), Strumigenys bernardi (Brown, 1960) and S. sistrura (Bolton, 1983), suggest a more advanced level of restoration of the covered area.
Located in Library / RBINS Staff Publications 2019
Article Reference Ant assemblage structure on cocoa trees in smallholder farms in the Centre Region of Cameroon
We investigated the ant community structure in cocoa farms in the Centre Region of Cameroon. Ants were collected on the cocoa trees during the years 2006 and 2007 using chemical knock‐down. We tested the hypothesis of the existence of deterministic factor in the structuration of ant mosaic using C‐Score; we assessed the relationship between the numerical dominant and subdominant ant species using Spearman correlation test and discussed on the influence of vegetation structure and farm management on the ant community structure. A total of 53 ant species belonging to 20 genera and five subfamilies were identified from a set of 51,525 workers collected. C‐score analysis supported the hypothesis that ant community were structured by competition. Negative relationships were found between dominant ant species. Farming practices which were mainly pruning, chemical treatment and habitat structure appeared to influence the ecological status and distribution of dominant ant species.
Located in Library / RBINS Staff Publications 2019
Article Reference An annotated checklist of the leaf beetles (Coleoptera, Chrysomelidae) from El Salvador, with additions from the Bechyné collection in the Royal Belgian Institute of Natural Sciences
A checklist of the species of leaf beetles (Coleoptera: Chrysomelidae) of El Salvador is presented based on data from literature and a digitization project of the Bechyné collection of the Royal Belgian Institute of Natural Sciences (RBINS). The RBINS collections contain a total of 2797 individual chrysomelid specimens from El Salvador, sorted into 89 species and 132 genera. In total, the current checklist contains 420 species, of which 33 are new records for El Slavador from the Bechyné collection. In these collections, there are also ten nomina nuda named by Bechyné, which need further study. The leaf beetle diversity in El Salvador, partly due to the country’s unstable political history, remains poorly studied, and many (new) species await discovery. This checklist provides a baseline for further study in El Salvador and nearby region.
Located in Library / RBINS Staff Publications 2019
Article Reference First record of the invasive longhorn crazy ant, Paratrechina longicornis (Latreille, 1802) (Hymenoptera: Formicidae) from Mt. Elgon, eastern Uganda
We report the first observation of the invasive longhorn crazy ant (Paratrechina longicornis) in the Mount Elgon region of eastern Uganda. About 43 000 ants were sampled in 256 locations throughout the Ugandan foot slopes of Mt. Elgon in the years 2014, 2015 and 2016. We found P. longicornis in five locations in and around the town of Budadiri, Sironko district. The visual species identification was confirmed by COI gene-based DNA barcoding. That this species was found in only a small area suggests that it has only been recently introduced. The impact that P. longicornis will have on the local agricultural system or the biodiversity within the Mount Elgon National Park remains unclear. The Mt. Elgon region is a unique key biodiversity area where baseline data can be collected now to quantify the effects of P. longicornis as it increases its distribution within the region
Located in Library / RBINS Staff Publications 2019
Article Reference Introduction history and genetic diversity of the invasive ant Solenopsis geminata in the Gala´pagos Islands
The Gala´pagos Islands constitute one of the most pristine tropical systems on Earth. However, the complex and fragile equilibrium of native species is threatened by invasive species, among which is one of the most successful ants in the world, the tropical fire ant, Solenopsis geminata. We characterized the genetic structure and diversity of populations of S. geminata in the Galapagos Islands and unravelled the archipelago colonization by combining Bayesian clustering methods and coalescent-based scenario testing. Using 12 microsatellite markers and one mitochondrial DNA fragment (COI), we analysed individuals collected in all main invaded islands of the archipelago and from the native areas in Costa Rica and mainland Ecuador. We also used mitochondrial DNA to infer evolutionary relationships of samples collected in Galapagos Islands, Ecuador, Costa Rica and other Latin American countries. Our results showed that genetic diversity was significantly lower in Galapagos Islands and mainland Ecuador populations when compared to Costa Rican populations, and that samples from Galapagos Islands and mainland Ecuador (Guayaquil) clustered in a single group and all share a single mtDNA haplotype. Approximate Bayesian Computation favoured a scenario assuming that populations from Galapagos Islands diverged from mainland Ecuador. The city of Guyaquil, an obligatory hub for tourism and trade, could act as a bridgehead.
Located in Library / RBINS Staff Publications 2018
Article Reference Impact of Laying Date and Fire Ants on Hatchlings of Chelonoidis porteri on Santa Cruz Island, Galápagos, Ecuador
Chelonoidis land tortoises are iconic species endemic to the Galápagos Islands of Ecuador. Their populations have been dramatically reduced by human activities in the last three centuries, including indirect effects such as the introduction of invasive species. We investigated the mortality of eggs and hatchlings in 48 nests of Chelonoidis porteri on Santa Cruz Island with regard to various mortality causes such as the occurrence of fire ants and the date of laying. The average mortality rate was 0.56. Tropical Fire Ants (Solenopsis geminata) were present within 1 m of 75% of the C. porteri nests, and we encountered fire ants in 12.5% of excavated nests. We found no relationship between Tropical Fire Ant abundance and C. porteri egg and hatchling survivorship. We observed no signs of mold inside the nests. We determined that early deposition dates were associated with lower clutch survival and identified egg development as the critical life stage. Finally, we discuss the potential impacts of fire ants and climate change on tortoise survival and reproduction and stress the importance of taking these factors into account for the conservation of the endemic land tortoises of the Galápagos
Located in Library / RBINS Staff Publications 2018
Article Reference The transition between coastal and offshore areas in the North Sea unraveled by suspended particle composition
Identifying the mechanisms that contribute to the variability of suspended particulate matter concentrations in coastal areas is important but difficult, especially due to the complexity of physical and biogeochemical interactions involved. Our study addresses this complexity and investigates changes in the horizontal spread and composition of particles, focusing on cross-coastal gradients in the southern North Sea and the English Channel. A semi-empirical model is applied on in situ data of SPM and its organic fraction to resolve the relationship between organic and inorganic suspended particles. The derived equations are applied onto remote sensing products of SPM concentration, which provide monthly synoptic maps of particulate organic matter concentrations (here, particulate organic nitrogen) at the surface together with their labile and less reactive fractions. Comparing these fractions of particulate organic matter reveals their characteristic features along the coastal-offshore gradient, with an area of increased settling rate for particles generally observed between 5 and 30 km from the coast. We identify this area as the transition zone between coastal and offshore waters with respect to particle dynamics. Presumably, in that area, the turbulence range and particle composition favor particle settling, while hydrodynamic processes tend to transport particles of the seabed back towards the coast. Bathymetry plays an important role in controlling the range of turbulent dissipation energy values in the water column, and we observe that the transition zone in the southern North Sea is generally confined to water depths below 20 m. Seasonal variations in suspended particle dynamics are linked to biological processes enhancing particle flocculation, which do not affect the location of the transition zone. We identify the criteria that allow a transition zone and discuss the cases where it is not observed in the domain. The impact of these particle dynamics on coastal carbon storage and export is discussed.
Located in Library / RBINS Staff Publications 2024 OA
Article Reference Espaces verts comme une alternative de conservation de la biodiversité en villes : le cas des fourmis (Hyménoptère : Formicidae) dans le district d’Abidjan (Côte d’Ivoire)
Objectif: Cette étude vise à évaluer le rôle des espaces verts dans la préservation de la biodiversité dans le district d’Abidjan (Côte d’Ivoire). Les fourmis ont été utilisées comme des indicateurs biologiques afin d’examiner l’influence des activités anthropiques sur la biodiversité de ces habitats localisés dans la matrice urbaine. Méthodologie et résultats : Les fourmis ont été collectées à l’aide d’appât de thon et du protocole ALL (pièges fosses et Winkler) dans trois types d’espaces verts (espaces verts publics, jardins botaniques et le Parc National du Banco). Les résultats indiquent que les espaces verts sont pollués (pourcentage de nuisance compris entre 1,7 % et 28,8 %) et illégalement occupés (pourcentage d’occupation compris entre 1,08 % à 52,3 %) par les activités humaines. Ces milieux abritent toutefois une faune de fourmis riche avec 176 espèces collectées. De plus, les jardins botaniques et les espaces verts publics partagent 8,51 % et 42,55 % des espèces de fourmis avec le Parc National du Banco, malgré leur faible connectivité à cet habitat naturel. Conclusion et application : Cette étude suggère que les espaces verts du district d’Abidjan présentent des atouts de conservation de la biodiversité, en particulier les fourmis. Toutefois, l’occupation de ces milieux par les activités commerciales conduit à leur dégradation progressive et à la disparition des communautés animales et végétales. Les résultats de cette étude devraient interpeller les décideurs à définir une politique de gestion des espaces verts et parcs urbains afin de rehausser leur valeur de conservation de la biodiversité en ville.
Located in Library / RBINS Staff Publications 2018
Article Reference Use of Soil and Litter Ants (Hymenoptera: Formicidae) as Biological Indicators of Soil Quality Under Different Land Uses in Southern Rwanda
The use of soil and litter arthropods as biological indicators is a way to assess environmental changes, where ant species in particular may serve as important indicators of soil quality. This study aimed at relating the abundance of soil and litter ant species to soil parameters under different tree species, both native and exotic, and varieties of coffee and banana plantations. Variations were found in soil physicochemical parameters. A total of 30 species belonging to 14 genera, and four subfamilies, the Formicinae, Dorylinae, Myrmicinae, and Ponerinae were identified. Higher abundance was found in coffee plantations compared to banana plantations, exotic and native tree species. Species of Camponotus cinctellus and Odontomachus troglodytes occurred in all land uses which is a sign of tolerance to a wide range of soil properties. In addition, these species, together with Myrmicaria SP02, Phrynoponera gabonensis, Camponotus SP06, Myrmicaria opaciventris, Pheidole SP03, Tetramorium simillimum, Pheidole SP01, and Tetramorium laevithorax were not strongly correlated with soil physicochemical parameters. Species of Pheidole SP02 and Camponotus SP05 were restricted to specific soil physicochemical properties, while species of Tetramorium zonacaciae and Bothroponera talpa discriminated between native tree species, coffee plantations, soil organic carbon, sandy soil texture, and aggregate stability. We concluded that these ant species can differently indicate the soil quality depending on the land use. We recommended further studies in order to generalize these findings
Located in Library / RBINS Staff Publications 2018
Article Reference Short-term changes in the structure of ant assemblages in a Guinean savanna under differing fire regimes at Lamto Scientific Reserve, Côte d’Ivoire
To maintain savanna vegetation, mid-seasonal fire has been applied since 1961 in the Lamto Savanna (Côte d’Ivoire). However, this prescribed fire has not impeded tree encroachment during recent years, nor have its effects on insect assemblages been documented. Also the impact of tree intrusion on insect assemblages is poorly studied in savanna. To prevent tree density increasing, a change in fire regime might be a solution. In this study, we examined the effect of different fire regimes (early, mid-seasonal and late fires) on leaf-litter ant assemblages in order to suggest appropriate measures for preventing tree invasion without having an effect on insect communities. Sampling was implemented by combining pitfall trapping and leaf-litter sampling before and after three different fire regimes, early, mid-seasonal and late fires. While the ant species richness declined after the passage of early and mid-seasonal fires, significantly more species were found in the burnt savanna after the late fire. However, the losses or gains of species due to different fire regimes did not cause severe changes in the ant species composition. Of the functional groups identified, only the generalists and specialist predators were respectively strongly affected by the early and mid-seasonal fires, certainly due to micro-habitat modification. Based on the trends observed in the present study, we suggest sampling other invertebrate fauna in similar savanna plots to find out if other insect groups have similar reactions to the applied fire regimes.
Located in Library / RBINS Staff Publications 2018