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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 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 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
The digitization of museum specimens is a key priority in the Digital Era. Digital databases help to avoid unnecessary manipulation hazards to delicate collections, increase their accessibility to third party researchers, and contribute to the ongoing documentation of global biodiversity. Time, workforce and the need of specialized infrastructures limit the processing of the vast number of specimens in natural history collections. Cheaper, easy-to-use methods and volunteer programs are developing quickly to help bridge the gap. We present the results of combining citizen science for the digitization of an entomological collection in conjunction with the cooperation of a taxonomic expert for the remote identification of samples. In addition, we provide an assessment of the avoided monetary costs and the time needed for each step of the process. A photographic inventory of specimens belonging to the leaf beetle genus Calligrapha was compiled by volunteers using a low-cost compact camera and the species were identified using these images. Using digital photographs allowed for a rapid screening of specimens in the collection and resulted in an updated taxonomic identification of the Calligrapha collection at the Royal Belgian Institute of Natural Sciences. The pictures of the specimens and their original labels, as well as the new information from this endeavor were placed in an online public catalogue. This study demonstrates a worked example of how digitization has led to a practical, useful outcome through cooperation with an end user and highlights the value of museum collection digitization projects
Located in Library / RBINS Staff Publications 2018
Lamto savanna soil known to have low agronomic value paradoxically has one of the highest grasses biomass productions in the world. During recent surveys, ant nest were encountered under some grass tufts and it as suggested that ants are able to influence the availability of resources for these grasses and also other organisms. An interaction is suspected between these savanna grass tufts and their associated ants. Three grasses species Andropogon schirensis, Hyparrhenia diplandra and Loudetia simplex were chosen to inventory ant communities associated with grass tufts and to assess the influence of ant communities on growth and productivity of perennial grasses. Three study sites were chosen and each was subdivided in two experimental plots of 2500 m². By systematic digging out method we were collected 38 ant species under grass tufts. They belong to 19 genera and 7 sub-families. Lamto herbaceous stratum was dominated by Camponotus acvapinensis. Diameter measures of grass tufts base at ground level, have allowed establishing the link between the size of ant nest and grass tufts size. Pearson coefficient r ranged no correlation between the size of ants nest and grass tufts size. The association rate with ants of one of the grasses Hyparrhenia diplandra was greater than for two other grasses studied Andropogon schirensis and Loudetia simplex (54.208 % versus 49.433 %, and 38.496 % respectively). Parameters such as grasses height, diameter (at ground level, and 10 cm above), dry biomass and seeds production were assessed. The results showed that Hyparrhenia diplandra with ant nest recorded the best results of growth and productivity. Association with ants nest is beneficial for the growth and productivity of Lamto perennial grasses.
Located in Library / RBINS Staff Publications 2018
Article Reference Do private coffee standards ‘walk the talk’ in improving socio-economic and environmental sustainability?
Private sustainability standards cover an increasingly large production area and involve an increasing number of farmers worldwide. They raise expectations among consumers about the economic, ethical and environmental implications of food production and trade; and attract donor funding to certification schemes. The sustainability impact of standards remains unclear as research focuses on either economic or environmental implications. We analyze both the socio-economic and environmental impacts of coffee standards in Uganda and show that these are not in line with expectations created towards consumers. We find that standards improve either productivity and farm incomes or biodiversity and carbon storage but fail to eliminate trade-offs between socioeconomic and environmental outcomes, even when combined in multiple certification. Our analysis is based on a unique combination of economic survey data and ecological field inventory data from a sample of certified and noncertified coffee farms. Our findings are relevant for farmers, food companies, policy-makers, donors and consumers. They imply that combining different standards in multiple certification is counterproductive; that the design of standards could improve to mitigate observed trade-offs between economic and environmental outcomes; and that this requires increased productivity within ecological boundaries, rather than a price premium and added control mechanisms through multiple certification
Located in Library / RBINS Staff Publications 2018
Article Reference Étude ostéologique de deux crémations provenant du site de Postel (Province d'Anvers, âge du Bronze)
Two cremations dating from the Bronze Age were discovered in the 1950s in a burial mound in Postel in the province of Antwerp. The colour of the skeletal remains indicates a homogeneous cremation with a temperature of at least 800°C. The most ancient individual (dated to phase I of the construction of the burial mound) is the most complete: about ¾ of its remains, which belong to all anatomical categories, were transferred from the pyre to the grave. The osteological study reveals that it was probably an adult male who was at least 25 years of age. The second subject is more recent (dated to Phase III) and is thought to have been an individual of undetermined sex, under 20 years old. The smaller quantity of remains and the absence of some anatomical categories, including fragile and small bones, that this was a deliberate sorting made by the cremation officiant. This type of selection has already been seen in other Belgian sites dating from the Bronze Age and later.
Located in Library / RBINS Staff Publications 2023
Article Reference First records of a supercolonial species of the Tapinoma nigerrimum complex in Belgium (Hymenoptera: Formicidae)
In the summer of 2014, a highly supercolonial Tapinoma was discovered in Ostend, Belgium. This was the first time a Tapinoma species with an invasive behaviour was discovered outdoors in Belgium. The ant belongs to the most widely distributed of four recognized species of the Tapinoma nigerrimum complex and is the only known species being invasive in areas north of the Mediterranean zone. In a first attempt to eliminate the species, a Demand 10CS insecticide solution treatment was initiated in 2015. First results illustrate that this treatment might be efficient, however a long-term monitoring of the site and its neighbourhood are suggested.
Located in Library / RBINS Staff Publications
Article Reference First observations in Belgium of the introduced ‘minute hooded beetle’ Arthrolips fasciata (Erichson, 1842) (Coleoptera: Corylophidae)
In September 2020 a specimen of the Corylophidae Arthrolips fasciata (Erichson, 1842) was discovered in mushrooms on decaying beech in a garden in Sint-Denijs-Westrem. In October 2020 a second specimen of this species was discovered in Beisbroek Sint-Andries Bruges also on decaying beech. These are the first records of the species in Belgium. Hence, we expect more Belgian records of this species in the near future. A species list of the Corylophidae known to occur in Belgium is given.
Located in Library / RBINS Staff Publications 2020