Polygyny and strong genetic structuring within an isolated population of the wood ant Formica rufa

Social structuring of populations within some Formica species exhibits considerable variation going from monodomous and monogynous populations to polydomous, polygynous populations. The wood ant species Formica rufa appears to be mainly monodomous and monogynous throughout most of its distribution area in central and northern Europe. Only occasionally it was mentioned that F. rufa can have both polygynous and monogynous colonies in the same geographical region. We studied an isolated polydomous F. rufa population in a deciduous mixed forest in the north-west of Belgium. The level of poly-domy within the colonies varied from monodomous to 11 nests per colony. Our genetic analysis of eight variable microsatellites suggest an oligo- to polygynous structure for at least the major part of the sampled nests. Relatedness amongst nest mate workers varies considerable within the population and colonies but confirms in general a polygynous structure. Additionally high genetic diversity (e.g. up to 8 out of 11 alleles per nest for the most variable locus) and high within nest genetic variance (93%) indicate that multiple queens contribute to the gene pool of workers of the same nest. Moreover significant genetic structuring among colonies indicates that gene flow between colonies is restricted and that exchange of workers between colonies is very limited. Finally we explain how possible factors as budding and the absence of Serviformica can explain the differences in genetic structure within this polygynous F. rufa population

First Record of Five Ant Species (Hymenoptera: Formicidae) from Rwanda

peer reviewedAnt studies conducted in Rwanda have reported a total of 105 ant species. However, this is an underestimation of the total ant richness since Rwanda is in a region rich in biodiversity. To fill the gaps, ants have been sampled in planted forests, coffee plantations, and different other land use types since 2017. Specimens have been collected using pitfall traps and hand collection, digitized, and identified to subfamily, genus, and species level. Results indicated that five ant species were found in Rwanda for the first time. These are Camponotus acvapimensis, Camponotus schoutedeni, Camponotus sericeus, Odontomachus assiniensis and Tetramorium sericeiventre. Specimens are deposited at the Royal Belgian Institute of Natural Science and the Rwanda Ant Collection. We recommend more ant studies focussing on their mode of living. This will result in more ant species newly recorded in the country and possibly new to scienc

The use of low cost compact cameras with focus stacking functionality in entomological digitization projects

Digitization of specimen collections has become a key priority of many natural history museums. The camera systems built for this purpose are expensive, providing a barrier in institutes with limited funding, and therefore hampering progress. An assessment is made on whether a low cost compact camera with image stacking functionality can help expedite the digitization process in large museums or provide smaller institutes and amateur entomologists with the means to digitize their collections. Images of a professional setup were compared with the Olympus Stylus TG-4 Tough, a low-cost compact camera with internal focus stacking functions. Parameters considered include image quality, digitization speed, price, and ease-of-use. The compact camera’s image quality, although inferior to the professional setup, is exceptional considering its fourfold lower price point. Producing the image slices in the compact camera is a matter of seconds and when optimal image quality is less of a priority, the internal stacking function omits the need for dedicated stacking software altogether, further decreasing the cost and speeding up the process. In general, it is found that, aware of its limitations, this compact camera is capable of digitizing entomological collections with sufficient quality. As technology advances, more institutes and amateur entomologists will be able to easily and affordably catalogue their specimens

Ant biodiversity conservation in Belgian calcareous grasslands: active management is vital

A list of ant species collected in eight calcareous grasslands in the Viroin valley (Viroinval, Belgium) is presented. Thirty species were identified, including Temnothorax albipennis, for the first time recorded in Belgium. Ant community composition and chorology of some ant species are discussed. Recommendations on how to use ant community composition and nest densities of several ant species to evaluate management in calcareous grasslands are given. It appears that in locations with encroachment of tall grasses (especially Brachypodium pinnatum) and spontaneous afforestation, due to a complete lack of or to inadequate management, most of the often rare xerophilic ant species are replaced by mesophilic, rather common species

Impact of chemical fertilizers on diversity and abundance of soil-litter arthropod communities in coffee and banana plantations in southern Rwanda

peer reviewedFew studies explored effects of chemical fertilizers on diversity and abundance of soillitter arthropods in the tropics. To fill this gap, a study focussed on the abundance of soil-litter arthropods and selected soil physicochemical properties in coffee plantations treated with chemical fertilizers and in plantations of coffee and banana treated with organic fertilizers and organic mulches in southern Rwanda. Each land use was replicated three times. Soil-litter arthropods were collected using pitfall traps and hand collection. They were identified to the family level using dichotomous keys. Soil have been collected using auger and taken to the laboratory for the analysis of soil pH, soil organic carbon, total nitrogen, phosphorus, and cation exchange capacity. Findings indicated a total of 12,945 individuals distributed into 3 classes, 16 orders, 50 families and 92 morphospecies, with higher abundance and diversity in coffee plantations treated with organic fertilizers and organic mulches. Collected soil-litter arthropods were mainly classified in the class Insecta, dominated in numbers by ants (Hymenoptera: Formicidae), while Coleoptera and Hemiptera had more families. However, soil under coffee plantations treated with organic fertilizers and organic mulches was acidic compared with the soil under coffee plantations treated with inorganic fertilizers and banana plantations treated with organic fertilizers and organic mulches. The relationships between soil-litter arthropods and soil physicochemical properties suggest that soil-litter arthropods respond to the land use independently from soil physicochemical properties. We recommend further studies in coffee and other crop plantations in other regions of Rwanda to verify the findings of this study

They live under our streets: ant nests (Hymenoptera, Formicidae) in urban pavements

peer reviewedIn the context of global insect decline, the urbanisation process plays a key role. However, urban pavements, which are considered to be impervious to biodiversity, can harbour ground-nesting insects under certain conditions. Recent observations have revealed the presence of Formicidae nests under urban pavements. The aim of this work is to determine the species richness of Formicidae nesting under urban pavements in the Brussels-Capital Region (Belgium) and to characterise their nest environment and soil texture. Seven ant species were identified in 120 nesting sites: Lasius niger, Lasius brunneus, Lasius flavus, Lasius fuliginosus, Tetramorium caespitum, Tetramorium impurum and Myrmica rugulosa. Concrete slabs or natural stones with a sandy sub-layer are the main structures in which ants nest. In addition, nests were mainly found under modular pavements with degraded rigid joints. The results of this work highlight the capacity of urban structures to host part of ant biodiversity in cities

From theory to practice: a photographic inventory of museum collections to optimize collection management

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

Distribution and habitat preferences of Galápagos ants (Hymenoptera: Formicidae).

Presentamos la primera revisión exhaustiva de los taxones de hormigas del archipiélago de Galápagos. La revisión se basa en datos recopilados durante búsquedas bibliográficas, encuestas de campo y la revisión de especímenes de museos, e incluye información sobre la distribución, hábitat y ecología de 47 especies. Se supone que al menos nueve de estas especies son nativas o endémicas de las islas y al menos 32 especies se han introducido a través de vías asociadas a los humanos. Se desconoce el estado de las seis especies restantes. La información compilada en este estudio nos permitirá comprender mejor el papel ecológico de las especies indígenas y su potencial como indicadores de la salud del ecosistema. La información de referencia sobre la distribución de hormigas introducidas será indispensable para evaluar el impacto y la propagación dentro del archipiélago.We present the first comprehensive review of the ant taxa of the Galápagos archipelago. The review is based on data gathered during literature searches, field surveys, and the revision ofmuseum specimens, and includes information on the distribution, habitat, and ecology of 47 species. At least nine of these species are assumed to be native or endemic to the islands and at least 32 species have been introduced through human-associated pathways. The status of the remaining six species is unknown. The information compiled in this study will allow us to better understand the ecological role of indigenous species and their potential as indicators of ecosystem health. Baseline information on the distribution of introduced ants will be indispensable for assessing impact and spread within the archipelago

Diversity and abundance of soil-litter arthropods and their relationships with soil physicochemical properties under different land uses in Rwanda

peer reviewedSoil-litter arthropods are critical for ecosystem functioning and sensitive to land use change, and hence to the variations in soil physicochemical properties. The relationships between soil-litter arthropod communities and soil physicochemical properties, however, remain poorly studied in Rwanda. We explored the relationships between the families of soil-litter arthropods and soil properties in exotic and native tree species, and in varieties of coffee and banana plantations. Soil-litter arthropods were sampled by using Berlese funnels, hand sorting, and pitfall traps, and were identified to the family level. Soil cores were collected and analysed for soil pH, available phosphorus, total nitrogen, soil organic carbon, silt, clay and sand. A total of 3176 individuals of soil-litter arthropods were collected, identified and classified into 13 orders and 23 families. Higher abundance was found in soil and litter sampled in plots of native tree species and banana plantations compared to exotic tree species and coffee plantations. Higher diversity was found in plots of native and exotic tree species. The analysis of soil physicochemical properties indicated that native tree species offer suitable conditions of studied soil properties. The study of the relationships between the land use, soil properties and families of soil-litter arthropods indicated positive correlations and relationships mainly in native tree species. We conclude that forest with native tree species play an important role in the conservation of soil-litter arthropods and for maintenance of better soil conditions