Olivier Blight

Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale | IMBE · université d'Avignon

The Argentine ant is one of the five worst invasive ants. Recently it has been shown that one of the main compounds of its pygidial gland, iridomyrmecin, is used as a venom against competitors and enemies. Here, we explore the variability in the quantities of iridomyrmecin of individual workers, along a range of locations pertaining to both its nat...

Ants are arthropods providing crucial ecosystem services such as soil structuring, nutrient cycling, seed dispersal and pest predation. Thus, their abundance and diversity need to be considered in approaches to improve sustainability of land use such as Mediterranean viticulture. In our study, we tested whether (1) inter-row vegetation and the abse...

Classifying organisms has a wide use and a long history in ecology. However, the meaning of a 'group of or-ganisms' and how to group organisms is still the subject of much theoretical and empirical work. Achieving this long quest requires simplifying the complexity of species niches for which relevant morphological, behavioural, biochemical or life...

Ecological engineering of degraded ecosystems often manipulates plants, with positive outcomes for their restoration or ecosystem services production. The importance of soil biota for successional plant communities has prompted consideration of direct inoculation (active) or attraction (passive) of soil organisms as a relevant restoration strategy....

The decline of arthropod populations observed in many parts of the world is a major component of the sixth mass extinction with intensive agriculture being one of its main drivers. Biodiversity-friendly farming practices are taking centre stage in the recovery process. In vineyards, vegetation cover is commonly used for production purposes, to redu...

Urbanization modifies environments worldwide creating opportunities for the establishment of invasive species, natives or non-natives, a main driver of global change. To understand the process of biological invasion, we need to decipher the interactions between urbanization and species traits. Within the Mediterranean Tapinoma nigerrimum species co...

Il y a déjà plus de 10 ans, le 7 août 2009, plusieurs millions de litres d’hydrocarbures (4 700 000 L) se déversaient en plein centre de la Réserve naturelle nationale des coussouls de Crau, en Provence-Alpes-Côte d’Azur, à la suite de la rupture accidentelle d’un oléoduc. Environ 5 ha d’un écosystème de pelouse méditerranéenne de type steppique, c...

There is a need to provide evidence-based assessments of the risks posed by invasive alien species (IAS) to underpin policies and prioritise action. Here we present the risk assessment for Wasmannia auropunctata. The risk assessments and associated management annexes were produced alongside tasks to develop and maintain a risk assessment template a...

There is a need to provide evidence-based assessments of the risks posed by invasive alien species (IAS) to underpin policies and prioritise action. Here we present the risk assessment of Solenopsis richteri. The risk assessments and associated management annexes were produced alongside tasks to develop and maintain a risk assessment template and t...

The decline of arthropod populations observed in many parts of the world is a major component of the sixth mass extinction with intensive agriculture being one of its main drivers. Biodiversity-friendly farming practices are taking centre stage in the recovery process. In vineyards, vegetation cover is commonly used for production purposes, to redu...

One of the main traits of invasive ants is the formation of supercolonies, large networks of polygynous nests lacking intraspecific competition, which allows them to reach high densities that facilitate their spread. However, different supercolonies exhibit different success in expanding along the world. Here, we explore whether the main chemical d...

The Argentine ant is an invasive species that has spread all over the world and is organized in several supercolonies. While there are many studies about factors promoting the expansion of the species, little is known about the factors affecting the variation in spread among the different supercolonies. We examined the environmental and spatial var...

Biodiversity-friendly farming practices are taking centre stage, with herbicide use sparking major public debate on human health. Vegetation cover is increasingly used to enhance agroecosystem biodiversity and functions, providing important ecosystem services like biological pest control. However, further information is required on the relationship...

Within ant communities, the biotic resistance of native species against invasive ones is expected to be rare, because invasive species are often highly dominant competitors. The invasive Argentine ant (Linepithema humile (Mayr)) often demonstrated numerical dominance against its opponents, increased aggressiveness, and ability to quickly recruit to...

Le 07 août 2009, la fuite accidentelle d’un oléoduc provoquait une marée noire terrestre sur plus de 5 hectares dans la plaine de la Crau, au cœur d’une réserve naturelle située dans le sud-est de la France. Devant l’ampleur de la pollution générée par les 4 700 m3 de pétrole brut épandu, 72 000 tonnes de sols pollués sont retirées l’année suivant...

Within a local assemblage, ecosystem engineers can have major impacts on population dynamics, community composition and ecosystem functions by transforming or creating new habitats. They act as an ecological filter altering community composition through a set of environmental variables. The impact of ants on their environment has been widely studie...

Dry grasslands of the North‐western Mediterranean Basin are semi‐natural species‐rich ecosystems, composed of many annual species and some structuring perennial species. As these grasslands have been used as rangelands for centuries, human management (grazing; fire regimes) is one of their main ecological and evolutionary drivers, along with the Me...

Prioritising the management of invasive alien species (IAS) is of global importance and within Europe integral to the EU IAS regulation. To prioritise management effectively the risks posed by IAS need to be assessed, but so too does the feasibility of their management. While the risk of IAS to the EU has been assessed, the feasibility of managemen...

Although not widely used, ecosystem engineers represent a promising and sustainable tool in nature-based ecosystem management and restoration. In grassland ecosystems, a few invertebrates that engineer soils have been identified as key species regulating soil nutrients and plant communities' diversity and dynamics. Here, we assessed the role of the...

Les fourmis, de par leurs actions mécaniques et chimiques sur leur environnement, sont souvent qualifiées d’ingénieures de l’écosystème, notamment au sein des formations végétales herbacées. En effet, la construction de galeries et de dépotoirs occasionne des changements dans la nature organique et minérale du sol qui peuvent notamment modifier les...

Seed dispersal mutualisms are essential to ensure the survival of diverse plant species and communities worldwide. Here, we investigated whether the invasive Argentine ant can replace native ants by fulfilling their functional role in the seed dispersal of the rare and threatened endemic myrmecochorous plant, Anchusa crispa, in Corsica (France). Ou...

Les fourmis sont des ingénieurs des écosystèmes dans les milieux de type « pelouse » Cependant alors que leurs impacts sur la végétation ont été largement étudiés, leurs rôles sur la faune du sol sont encore peu connus Bien que les pelouses possèdent généralement une importante biodiversité depuis la deuxième moitié du 20 e siècle, une perte signif...

La plaine de la Crau, située au sud-est de la France, comprend, notamment, un écosystème de type steppique d’environ 11 500 hectares dont cinq hectares ont été dégradés par une fuite d’hydrocarbure en 2009. Suite au transfert de 72 000 tonnes de sol identique provenant d’une carrière à proximité, une régénération de la végétation a été mesurée aprè...

Identifying the factors that promote the success of biological invasions is a key pursuit in ecology. To date, the link between animal personality and invasiveness has rarely been studied. Here, we examined in the laboratory how Argentine ant populations from the species’ native and introduced ranges differed in a suite of behaviours related to spe...

Consistent individual differences in personality traits should be favoured when those traits contribute to consistent individual fitness differences. However, how variations in behaviours are related to productivity remains scarcely explored in social species, particularly in insects. Here, we investigated whether exploratory, boldness, and brood r...

Among invasive species, ants are a particularly prominent group with enormous impacts on native biodiversity and ecosystem functioning. Globalization and ongoing climate change are likely to increase the rate of ant invasions in the future, leading to simultaneous introductions of several highly invasive species within the same area. Here, we inves...

Climate change and biological invasions are among the greatest threats to biodiversity, and their impacts might increase by the end of this century. Among invasive species, ants are a prominent group due to their negative impacts on native species, ecosystem processes, human and animal health, agro-ecosystems, and the economy. Ants are expected to...

Caste determination in social insects has long been considered to exemplify socially mediated phenotypic plasticity: young larvae can develop into queens or workers depending on the social environment. However, recent studies have challenged this view by showing that, in some species, larval development can be biased early by factors such as larval...

Social insects have been particularly evolutionarily successful: they dominate terrestrial ecosystems all over the globe. Their success stems from their social organization, where one or a few individuals reproduce, whereas others carry out different colony tasks. From an evolutionary standpoint, social species are particularly interesting because...

Plusieurs stations d’habitats différents ont été échantillonnées sur le site-atelier pour déterminer la richesse de la myrmécofaune et rechercher des espèces d’intérêt biologique ou des espèces invasives. Le résultat de cette étude met en évidence une richesse insoupçonnée en fourmis, avec 34 espèces, représentant près de 16% de la myrmécofaune fra...

Social insects have been particularly evolutionarily successful: they dominate terrestrial ecosystems all over the globe. Their success stems from their social organization, where one or a few individuals reproduce, whereas others carry out different colony tasks. From an evolutionary standpoint, social species are particularly interesting because...

Ants are among the most problematic invasive species. They displace numerous native species, alter ecosystem processes, and can have negative impacts on agriculture and human health. In part, their success might stem from a departure from the discovery–dominance trade-off that can promote coexistence in native ant communities, that is, invasive ant...

Ants figure prominently among the worst invasive species because of their enormous ecological and economic impacts. However, it remains to be investigated which species would be behaviourally dominant when confronted with another invasive ant species, should two species be introduced in the same area. In the future, many regions might have suitable...

1. Competition by dominant species is thought to be key to structuring ant communities. However, recent findings suggest that the effect of dominant species on communities is less pronounced than previously assumed.2. The aim of the present study was to identify the role of dominant ants in the organisation of Mediterranean communities, particularl...

Abstract In invasion areas, the Argentine ant (Linepithema humile) forms huge supercolonies with free exchange of individuals among nests. Two continental supercolonies on the French mediterranean coast, the Main European supercolony and the Corsican supercolony, are known to contain workers showing moderate to high levels of inter-supercolony aggr...

Correct species identification is a precondition for biological study, yet despite a long history of morphological investigations, the systematic position of many ant species remains unclear. Here, we compared and identified cuticular hydrocarbon profiles of workers of several species of Tapinoma from Algeria, Morocco, Israel, France (mainland and...

Les auteurs signalent la découverte en France continentale du Tenebrionidae Cnemeplatia atropos A. Costa, 1847, et rapportent une nouvelle observation de cette espèce en Corse.

In their invasive ranges, Argentine ant populations often form one geographically vast supercolony, genetically and chemically uniform within which there is no intraspecific aggression. Here we present regional patterns of intraspecific aggression, cuticular hydrocarbons (CHCs) and population genetics of 18 nesting sites across Corsica and the Fren...

The dry grasslands of La Crau, a pseudo-steppe ecosystem located in Southern France, have experienced drastic reduction and degradation due to intensive agricultural activities for the past 50years, leading to changes in their beetle assemblage. This valuable ecosystem is characterized by 50% stone cover, consisting of remnants from an old riverbed...

The Argentine ant, Linepithema humile, has invaded urban, agricultural, and natural habitats worldwide, causing economic damages and disrupting ecosystem processes. As a contribution to Argentine ant management, the present study aimed to test in situ the efficacy of an imidacloprid gel bait. We tested the gel efficacy in terms of Argentine ant era...

Argentine ants (Linepithema humile) usually actively displace native ants through a combination of rapid recruitment, high numerical dominance and intense aggressive fights. However, in some cases, native ants can offer a strong resistance. In Corsica, a French Mediterranean island, local resistance by the dominant Tapinoma nigerrimum has been prop...

The Argentine ant (Linepithema humile, Mayr) is a highly invasive species that has successfully spread from its native range in South America across many zones of the globe. In Southern Europe, two continental supercolonies have been identified, the Catalonian supercolony and the main European supercolony spreading over 6,000km. In Corsica, a Frenc...

In introduced areas, Argentine ant (Linepithema humile) is known to form huge colony structured called supercolony with free exchange of individuals among nests. Here, we present analyzes of Argentine ant recognition cues (cuticular hydrocarbons) and aggressive interactions between 8 coastal sites in Provence-Côte d’Azur (France). The results of be...

The Argentine ant, Linepithema humile (Dolichoderinae), is one of the most widespread invasive ant species in the world. When established in optimal habitat, this species usually excludes most other local ants and can heavily impact other arthropods as well. Although Argentine ants have been present in southern Europe for more than 100 years, they...

Since the middle of the 20th century, improvements in analytical technologies have permitted the identification of cuticular hydrocarbons present on the cuticle of almost all insects. Concomitantly, a great deal of attention has been paid to the determination of their role at the individual, colonial, and populational level. Many studies pointed to...