Abstract. 1. We investigated ant communities in all main vegetation zones of the model island of ... more Abstract. 1. We investigated ant communities in all main vegetation zones of the model island of Santa Cruz in the Galápagos archipelago (155 collection points, spread over 21 sites; 28 ant species collected), and evaluated the distribution, coexistence, and effect of environmental factors in a community composed of endemic, probably endemic, and introduced ants of the New World and exotic origin. 2. Introduced species were the most frequent, occurring in 98% of the samples, yet endemic and probably endemic species still occurred in 54% of the samples, and constituted one of three most common species. The present study revealed that the habitat type along with altitude and the tree cover are the primary factors shaping ant community composition. Little evidence was found for a competitively structured assemblage of ant species. 3. The present study confirmed the predominance of two dominant invasive species, Solenopsis geminata Fabricius and Wasmannia auropunctata Roger, whose abundances are negatively correlated. The abundance of S. geminata is positively correlated with the overall species richness, and with the proportion of other introduced species. The presence of both invasive ants is associated with a low evenness of ant communities. 4. The present study (i) stresses the dominance of introduced species and the relative resistance of endemic species, (ii) highlights the on-going processes of species introductions and (iii) points out the need for adequate monitoring and conservation of the pristine and threatened environments that constitute the Galápagos Islands. Key words. Ant communities, biological invasions, Formicidae, Solenopsis geminata, Wasmannia auropunctata.
"Solenopsis is a widespread ant genus and the identification of its species is notoriously diffic... more "Solenopsis is a widespread ant genus and the identification of its species is notoriously difficult. Hence, investigation of their distribution along elevational gradients is challenging. Our aims were (1) to test the complementarity of the morphological and DNA barcoding approaches for Solenopsis species identification, and (2) to assess species diversity and distribution along an altitudinal gradient in the Ecuadorian Andes. Ants were collected in five localities between 1000 and 3000 m above sea level. In total, 24 morphospecies were identified along the gradient and 14 of them were barcoded. Seven morphospecies were confirmed by the molecular approach. Three others, occurring sympatrically and possessing clear diagnostic characters, showed low genetic divergence. Representatives of a further four morphospecies were split into nine clusters by COI and nuclear wingless genetic markers, suggesting the existence of cryptic species. Examination of gynes revealed potential diagnostic characters for morphological discrimination. Solenopsis species were found up to an altitudinal record of 3000 m. Most morphospecies (20 of 24) were found at a single elevation. Our results suggest a high species turnover along the gradient, and point to the use of morphological and DNA barcoding approaches as necessary for differentiating among Solenopsis species."
Tropical fire ant (TFA), Solenopsis geminata (Fabricius, 1804), is considered as one of the most ... more Tropical fire ant (TFA), Solenopsis geminata (Fabricius, 1804), is considered as one of the most serious threats to the terrestrial fauna of Galápagos, yet little is known about its distribution and impact in the archipelago. We reviewed literature, studied museum specimens and sampled over 62 sites on ten islands and islets in order to update the distribution of TFA. Since the 1980’s, species occurrences for TFA have increased from three to 115 localities, and the species is now recorded on seven islands and 11 islets. Sixty-six new records were registered since the last review in 2008, including the islets Bayas, Champion, Cuevas, and Eden. TFA seems to be present in a wide range of habitats with a clear predominance in human-disturbed zones. Our data, compiled with previous studies, suggest that TFA can behaviorally dominate other ants. TFA was collected on 28 nesting sites of endangered and/or endemic vertebrate species, where it constitutes a potential or proven threat. This study identifi es potential invasion sites as well as endemic species that may further be impacted by this highly invasive ant. It also recom- mends regular monitoring to prevent further invasion
During a ten-days ant course carried out in November 2012 within the framework of a Belgian Focal... more During a ten-days ant course carried out in November 2012 within the framework of a Belgian Focal Point to the Global Taxonomy Initiative GTI type 2 grant, eight students and four instructors collected 22 ant species at ten sites distributed along an altitudinal gradient on Santa Cruz Island in the Galápagos Archipelago (Ecuador). Disturbed and urbanized zones as well as natural areas were visited. We discuss the results and link the collected species to altitude and vegetation types occurring on Santa Cruz Island. Keywords: Formicidae, Galápagos Archipelago, habitat preferences, species lists, invasive species
DI-fusion, le Dépôt institutionnel numérique de l'ULB, est l'outil de référencementde la producti... more DI-fusion, le Dépôt institutionnel numérique de l'ULB, est l'outil de référencementde la production scientifique de l'ULB.L'interface de recherche DI-fusion permet de consulter les publications des chercheurs de l'ULB et les thèses qui y ont été défendues.
Abstract. 1. We investigated ant communities in all main vegetation zones of the model island of ... more Abstract. 1. We investigated ant communities in all main vegetation zones of the model island of Santa Cruz in the Galápagos archipelago (155 collection points, spread over 21 sites; 28 ant species collected), and evaluated the distribution, coexistence, and effect of environmental factors in a community composed of endemic, probably endemic, and introduced ants of the New World and exotic origin. 2. Introduced species were the most frequent, occurring in 98% of the samples, yet endemic and probably endemic species still occurred in 54% of the samples, and constituted one of three most common species. The present study revealed that the habitat type along with altitude and the tree cover are the primary factors shaping ant community composition. Little evidence was found for a competitively structured assemblage of ant species. 3. The present study confirmed the predominance of two dominant invasive species, Solenopsis geminata Fabricius and Wasmannia auropunctata Roger, whose abundances are negatively correlated. The abundance of S. geminata is positively correlated with the overall species richness, and with the proportion of other introduced species. The presence of both invasive ants is associated with a low evenness of ant communities. 4. The present study (i) stresses the dominance of introduced species and the relative resistance of endemic species, (ii) highlights the on-going processes of species introductions and (iii) points out the need for adequate monitoring and conservation of the pristine and threatened environments that constitute the Galápagos Islands. Key words. Ant communities, biological invasions, Formicidae, Solenopsis geminata, Wasmannia auropunctata.
"Solenopsis is a widespread ant genus and the identification of its species is notoriously diffic... more "Solenopsis is a widespread ant genus and the identification of its species is notoriously difficult. Hence, investigation of their distribution along elevational gradients is challenging. Our aims were (1) to test the complementarity of the morphological and DNA barcoding approaches for Solenopsis species identification, and (2) to assess species diversity and distribution along an altitudinal gradient in the Ecuadorian Andes. Ants were collected in five localities between 1000 and 3000 m above sea level. In total, 24 morphospecies were identified along the gradient and 14 of them were barcoded. Seven morphospecies were confirmed by the molecular approach. Three others, occurring sympatrically and possessing clear diagnostic characters, showed low genetic divergence. Representatives of a further four morphospecies were split into nine clusters by COI and nuclear wingless genetic markers, suggesting the existence of cryptic species. Examination of gynes revealed potential diagnostic characters for morphological discrimination. Solenopsis species were found up to an altitudinal record of 3000 m. Most morphospecies (20 of 24) were found at a single elevation. Our results suggest a high species turnover along the gradient, and point to the use of morphological and DNA barcoding approaches as necessary for differentiating among Solenopsis species."
Tropical fire ant (TFA), Solenopsis geminata (Fabricius, 1804), is considered as one of the most ... more Tropical fire ant (TFA), Solenopsis geminata (Fabricius, 1804), is considered as one of the most serious threats to the terrestrial fauna of Galápagos, yet little is known about its distribution and impact in the archipelago. We reviewed literature, studied museum specimens and sampled over 62 sites on ten islands and islets in order to update the distribution of TFA. Since the 1980’s, species occurrences for TFA have increased from three to 115 localities, and the species is now recorded on seven islands and 11 islets. Sixty-six new records were registered since the last review in 2008, including the islets Bayas, Champion, Cuevas, and Eden. TFA seems to be present in a wide range of habitats with a clear predominance in human-disturbed zones. Our data, compiled with previous studies, suggest that TFA can behaviorally dominate other ants. TFA was collected on 28 nesting sites of endangered and/or endemic vertebrate species, where it constitutes a potential or proven threat. This study identifi es potential invasion sites as well as endemic species that may further be impacted by this highly invasive ant. It also recom- mends regular monitoring to prevent further invasion
During a ten-days ant course carried out in November 2012 within the framework of a Belgian Focal... more During a ten-days ant course carried out in November 2012 within the framework of a Belgian Focal Point to the Global Taxonomy Initiative GTI type 2 grant, eight students and four instructors collected 22 ant species at ten sites distributed along an altitudinal gradient on Santa Cruz Island in the Galápagos Archipelago (Ecuador). Disturbed and urbanized zones as well as natural areas were visited. We discuss the results and link the collected species to altitude and vegetation types occurring on Santa Cruz Island. Keywords: Formicidae, Galápagos Archipelago, habitat preferences, species lists, invasive species
DI-fusion, le Dépôt institutionnel numérique de l'ULB, est l'outil de référencementde la producti... more DI-fusion, le Dépôt institutionnel numérique de l'ULB, est l'outil de référencementde la production scientifique de l'ULB.L'interface de recherche DI-fusion permet de consulter les publications des chercheurs de l'ULB et les thèses qui y ont été défendues.
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2. Introduced species were the most frequent, occurring in 98% of the samples,
yet endemic and probably endemic species still occurred in 54% of the samples, and
constituted one of three most common species. The present study revealed that the
habitat type along with altitude and the tree cover are the primary factors shaping ant community composition. Little evidence was found for a competitively structured
assemblage of ant species.
3. The present study confirmed the predominance of two dominant invasive species, Solenopsis geminata Fabricius and Wasmannia auropunctata Roger, whose abundances are negatively correlated. The abundance of S. geminata is positively correlated with the overall species richness, and with the proportion of other introduced species. The presence of both invasive ants is associated with a low evenness of ant communities.
4. The present study (i) stresses the dominance of introduced species and the relative resistance of endemic species, (ii) highlights the on-going processes of species introductions and (iii) points out the need for adequate monitoring and conservation of the pristine and threatened environments that constitute the Galápagos Islands.
Key words. Ant communities, biological invasions, Formicidae, Solenopsis geminata, Wasmannia auropunctata.
Galápagos Archipelago (Ecuador). Disturbed and urbanized zones as well as natural areas were visited. We discuss the results and link the collected species to altitude and vegetation types occurring on Santa Cruz Island.
Keywords: Formicidae, Galápagos Archipelago, habitat preferences, species lists, invasive species
2. Introduced species were the most frequent, occurring in 98% of the samples,
yet endemic and probably endemic species still occurred in 54% of the samples, and
constituted one of three most common species. The present study revealed that the
habitat type along with altitude and the tree cover are the primary factors shaping ant community composition. Little evidence was found for a competitively structured
assemblage of ant species.
3. The present study confirmed the predominance of two dominant invasive species, Solenopsis geminata Fabricius and Wasmannia auropunctata Roger, whose abundances are negatively correlated. The abundance of S. geminata is positively correlated with the overall species richness, and with the proportion of other introduced species. The presence of both invasive ants is associated with a low evenness of ant communities.
4. The present study (i) stresses the dominance of introduced species and the relative resistance of endemic species, (ii) highlights the on-going processes of species introductions and (iii) points out the need for adequate monitoring and conservation of the pristine and threatened environments that constitute the Galápagos Islands.
Key words. Ant communities, biological invasions, Formicidae, Solenopsis geminata, Wasmannia auropunctata.
Galápagos Archipelago (Ecuador). Disturbed and urbanized zones as well as natural areas were visited. We discuss the results and link the collected species to altitude and vegetation types occurring on Santa Cruz Island.
Keywords: Formicidae, Galápagos Archipelago, habitat preferences, species lists, invasive species