Claire Detrain

• PhD
• Research Director at Université Libre de Bruxelles

Insect societies, which are at a high risk of disease outbreaks, have evolved sanitary strategies that contribute to their social immunity. Here, we investigated in the red ant Myrmica rubra, how the discarding of nestmate cadavers is socially organized depending on the associated pathogenicity. We examined whether necrophoresis is carried out by a...

Ant colonies are often considered to be highly efficient societies skilled at cooperating and sharing workload among workers. Yet, several studies have revealed low colony activity levels and a subgroup of specialized inactive individuals, raising questions about their role. This study investigates whether these inactive ants differ in their sensit...

The use of predatory arthropods in biological pest control in agriculture can generate resistance by farmers when these beneficials become noxious for them or their crops. The African weaver ant, Oecophylla longinoda (Hymenoptera: Formicidae), an effective biocontrol agent of pests, particularly Bactrocera dorsalis fruit flies in mango orchards in...

Honeydew is the keystone of many interactions between aphids and their predators, parasitoids, and mutualistic partners. Despite the crucial importance of honeydew in aphid-ant mutualism, very few studies have investigated the potential impacts of climate change on its production and composition. Here, we quantified changes in sugar compounds and t...

Although the activity levels of insect societies are assumed to contribute to their ergonomic efficiency, most studies of the temporal organization of ant colony activity have focused on only a few species. Little is known about the variation in activity patterns across colonies and species, and in different environmental contexts. In this study, t...

The ecological success of ants relies on their high level of sociality and cooperation between genetically related nestmates. However, these group-living insects suffer from elevated risks of disease outbreak in the whole nest. To face this sanitary challenge, social and spatial distancing of pathogen-exposed individuals from susceptible nestmates...

Eusocial insects are exposed to a wide range of pathogens while foraging outside their nest. We know that opportunistic scavenging ants are able to assess the sanitary state of food and to discriminate a prey which died from infection by the entomopathogenic fungus Metarhizium brunneum. Here, we investigate whether a contamination of the environmen...

Honeydew is the keystone of many interactions between aphids and their predators, parasitoids, or mutualistic partners. Despite the crucial importance of honeydew in the aphid-ant mutualism, very few studies have investigated the potential impact of climate change on its production and composition. Here, we quantified changes in the sugar compounds...

1. Climate change will likely affect the association between species interacting at different trophic levels. However, studies focusing on the impact of an elevation of temperature on ant‐hemipteran mutualism remain scarce. 2. In the present study we investigated, in laboratory conditions, the foraging behaviour of the ant Lasius niger and its mutu...

Insect societies are challenged by harmful pathogens that originate from waste, such as faeces, food leftovers or corpses. The discarding of waste to outside the nest reduces these sanitary risks and contributes to the social immunity of ant colonies. In this study, we tested whether the nest-cleaning behaviour in Myrmica rubra colonies differed de...

Ants are the hosts of many microorganisms, including pathogens that are incidentally brought inside the nest by foragers. This is particularly true for scavenging species, which collect hazardous food such as dead insects. Foragers limit sanitary risks by not retrieving highly infectious prey releasing entomopathogenic fungal spores. This study inv...

In social insects, collective choices between food sources are based on self-organized mechanisms where information about resources are locally processed by the foragers. Such a collective decision emerges from the competition between pheromone trails leading to different resources but also between the recruiting stimuli emitted by successful forag...

The nest architecture of social insects deeply impacts the spatial distribution of nestmates their interactions, information exchanges and collective responses. In particular, the number of nest entrances can influence the interactions taking place beyond the nest boundaries and the emergence of collective structures like foraging trails. Here, we...

Nests of social insects are an important area for the exchange of food and information among workers. We investigated how the topology of nest chambers (as opposed to nest size or environmental factors) affects the spatial distribution of nestmates and the foraging behavior of Myrmica rubra ant colonies. Colonies were housed in artificial nests, ea...

The ecological success of ants relies on their ability to discover and collectively exploit available resources. In this process, the nest entrances are key locations at which foragers transfer food and information about the surrounding environment. We assume that the number of nest entrances regulates social exchanges between foragers and inner-ne...

Insect societies have developed sanitary strategies, one of which is the avoidance of infectious food resources as a primary line of defence. Using binary choices, we investigated whether Myrmica rubra ants can identify prey that has been artificially infected with the entomopathogenic fungus, Metarhizium brunneum. We compared the ants' foraging be...

Division of labor in social insects has been explained by response threshold models which are based on differential responses to task-specific stimuli. In the present study, we argue that other types of stimuli, such as location-related cues, which are correlated with but not directly linked to task performance, may be significant. Using the black...

Non-granivorous ant species that contribute to seed dispersal (myrmecochory sensu stricto) are assumed to benefit from the larval consumption of elaiosomes, the lipid-rich appendages of myrmecochorous seeds. It is, however, questionable whether this ant–plant interaction is truly mutualistic, since some ant partners do not show a clear-cut fitness...

Recent studies about mutualism consider the complexity and versatility of the relationship, in addition to highlighting the importance of the cost/benefit balance between the two protagonists. Because species interactions are highly dependent on the environment, the climate changes foreseen for the coming years are expected to have significant impa...

1. Myrmecochory sensu stricto is an ant–plant mutualism in which non‐granivorous ants disperse plant diaspores after feeding on their nutrient‐rich seed appendage, the elaiosome. Phenological traits associated with the diaspore can influence the behaviour of ants and thus their ultimate efficiency as seed dispersers. 2. This study investigated how...

Nest entrances are key locations where information about environmental opportunities and constraints are shared between foragers and inner-nest workers. However, despite its functional value, we still lack a detailed characterisation of the interface between the nest and the environment. Here, we identified the social interface in the ant Myrmica r...

As entomopathogens are detrimental to the development or even survival of insect societies, ant colonies should avoid digging into a substrate that is contaminated by fungal spores. Here, we test the hypotheses that Myrmica rubra ant workers (i) detect and avoid fungus-infected substrates and (ii) excavate nest patterns that minimize their exposure...

Water motion, because of its potential to dislodge intertidal organisms, plays a crucial role in shaping marine communities as it creates available spaces suitable for interactions, settlement and colonization. To understand how water flow influences the behavioural ecology of benthic species such as echinoids, we investigated how the sea urchin Pa...

Group-living species have to deal with higher risks of exposure to pathogens and of disease propagation between group members. Insect societies have therefore evolved behaviours that contribute to the social immunity of the whole colony. Here, we investigate how the sanitary strategies displayed by ants depend on colony size, which is known to infl...

In social insects, individuals infected by pathogens withdraw from the nest, preventing the spread of diseases among genetically related nestmates and thereby contributing to the ‘social immunity’ of the colony. Here we investigated the extent to which the isolation of sick ants correlates with changes in their behavioural responses to environmenta...

1. Aphid‐tending ants that feed on honeydew have evolved strategies against aphidophagous insects and tune their aggressive behaviour according to the level of danger for their trophobionts. Here we investigate how L asius niger L innaeus ( H ymenoptera: F ormicidae) ants react to different instars of E pisyrphus balteatus D e G eer ( D iptera: S y...

Myrmecochory is the process of seed dispersal by ants; however, it is highly challenging to study, mainly because of the small size of both partners and the comparatively large range of dispersal. The mutualistic interaction between ants and seeds involves the former retrieving diaspores, consuming their elaiosome (a nutrient-rich appendage), and t...

Understanding how climate change will affect species interactions is a challenge for all branches of ecology. We have only limited understanding of how increasing temperature and atmospheric CO2 and O3 levels will affect pheromone-mediated communication among insects. Based on the existing literature, we suggest that the entire process of pheromona...

Social insects have evolved an array of individual and social behaviours that limit pathogen entrance and spread within the colony. The detection of ectoparasites or of fungal spores on a nestmate body triggers their removal by allogrooming and appears as a primary component of social prophylaxis. However, in the case of fungal infection, one may w...

Mutualistic interactions between ant and aphid species have been the subject of considerable historical and contemporary investigations, the primary benefits being cleaning and protection for the aphids and carbohydrate-rich honeydew for the ants. Questions remained, however, as to the volatile semiochemical factor influencing this relationship. A...

Myrmecochorous diaspores bear a nutrient-rich appendage, the elaiosome, attractive to ant workers that retrieve them into the nest, detach the elaiosome and reject the seed intact. While this interaction is beneficial for the plant partner by ensuring its seed dispersal, elaio-some consumption has various effects −positive, negative or none − on an...

Ants have developed prophylactic and hygienic behaviours in order to limit risks of pathogenic outbreaks inside their nest, which are often called social immunity. Here, we test whether ants can adapt the "social immune response" to the level of pathogenic risk in the colony. We challenged Myrmica rubra colonies with dead nestmates that had either...

The mutualistic relationships between certain ant and aphid species are well known, the primary benefits being protection for the aphids and carbohydrate-rich honeydew for the ants. Questions remain, however, as to the exact semiochemical factors that establish and maintain such relationships. In this study, we used a series of treatments and assoc...

Sociality increases exposure to pathogens. Therefore, social insects have developed a wide range of behavioural defences, known as ‘social immunity’. However, the benefits of these behaviours in terms of colony survival have been scarcely investigated. We tested the survival advantage of prophylaxis, i.e. corpse removal, in ants. Over 50 days, we c...

In the ant species Tetramorium caespitum, collective foraging relies on group mass communication in which successful scouts lay a recruitment trail but also guide a group of nestmates to the food source. We conducted experiments to understand how group leaders may improve the success of recruits in reaching the food source and whether they adjust t...

Carbohydrate sources such as plant exudates, nectar and honeydew represent the main source of energy for many ant species and contribute towards maintaining their mutualistic relationships with plants or aphid colonies. Here we characterise the sensitivity, feeding response curve and food intake efficiency of the aphid tending ant, Lasius niger for...

In many vertebrates and invertebrates, living in a group may influence the life history traits, physiology and behaviour of its individual members, whereas genetic relatedness affects social interactions among individuals in a group. The two-spotted spider mite Tetranychus urticae is characterised by a communal organization, in which silk productio...

The aphid–ant mutualistic relationships are not necessarily obligate for neither partners but evidence is that such interactions provide them strong advantages in terms of global fitness. While it is largely assumed that ants actively search for their mutualistic partners namely using volatile cues; whether winged aphids (i.e. aphids’ most mobile f...

The division of labour plays a major role in the success of social insects. For instance, through social prophylaxis, the spread of pathogens within the colony can be reduced if corpse removal is the concern of a specialized group of ants. However, in relatively small colonies, the number of dead individuals and the amount of waste may be too low t...

In order to decrease the risk of pathogen transmission, ants remove corpses from the vicinity of nests, but little is known about the underlying mechanisms. In particular, it is unclear how the odor profile of corpses changes with time since death and how any changes might relate to behavior. We have addressed these questions in the red ant Myrmica...

In silk-spinning arthropods, silk can be used for web building, protection, and communication. Silk is an informative material about the presence of conspecifics. It can therefore inform on habitat suitability and hence assist in habitat choice. In this context, we investigated the influence of silk on microhabitat choice by the two-spotted spider...

The two-spotted spider mite Tetranychus urticae is a silk producer known to live in groups. Its silk production plays an important role in protection against external aggressions (predators, rains, etc.). It is also used for group dispersal through the formation of silkballs or as a thread during individual migration by walking. Until now, the role...

Optimality theory predicts that females tend to maximize their offspring survival by choosing the egg-laying site. In this context, the use of conspecific cues allows a more reliable assessment of the habitat quality. To test this hypothesis, Tetranychus urticae Koch is an appropriate biological model as it is a phytophagous mite living in group, p...

Living in groups raises important issues concerning waste management and related sanitary risks. Social insects such as ants live at high densities with genetically related individuals within confined and humid nests, all these factors being highly favorable for the spread of pathogens. Therefore, in addition to individual immunity, a social prophy...

For collective decisions to be made, the information acquired by experienced individuals about resources' location has to be shared with naïve individuals through recruitment. Here, we investigate the properties of collective responses arising from a leader-based recruitment and a self-organized communication by chemical trails. We develop a genera...

The mutualistic relationships that occur between myrmecophilous aphids and ants are based on the rich food supply that honeydew represents for ants and on the protection they provide against aphid natural enemies. While aphid predators and parasitoids actively forage for oviposition sites by using aphid semiochemicals, scouts of aphid-tending ant s...

Choosing a suitable habitat is a main step in the settlement process, particularly for species having weak movement abilities. Reliable cues are thus needed for habitat selection. In silk-spinning arthropods, silk can be used as a social cue to select an appropriate location. Silk can also provide information on the presence of related or non-relat...

Competition acts as a major force in shaping spatially and/or temporally the foraging activity of ant colonies. Interference competition between colonies in particular is widespread in ants where it can prevent the physical access of competitors to a resource, either directly by fighting or indirectly, by segregating the colony foraging areas. Alth...

Spatial distribution of ant workers within the nest is a key element of the colony social organization contributing to the efficiency of task performance and division of labour. Spatial distribution must be efficiently organized when ants are highly starved and have to get food rapidly. By studying ants’ behaviour within the nest during the beginni...

The two-spotted spider mite Tetranychus urticae is a silk producer known to live in groups with a common silk web that can cover entire plants and protect mites against predators, rain and wind. Silk also plays an important role during collective migration by aerial dispersal or by walking. In this context, we studied the locomotor activity i.e. ti...

Tetranychus urticae (Acari: Tetranychidae) is a phytophagous mite that forms huge colonies. All active members of a colony (immatures and matures, females and males) spin silken threads. These mites construct a common web that protects the colony from external aggression. The silk coverage is well-known to provide advantages to the colony but very...

The two-spotted spider mite Tetranychus urticae is a silk producer known to live in groups. Its silk production plays an important role in protection against external aggressions (predators, rains, etc.). It is also used for group dispersal through the formation of silkballs or as a thread during individual migration by walking. Until now, the role...

In social insects, the foraging activity usually increases with the length of food deprivation. In Lasius niger, a mass-recruiting ant species, the foraging adjustment to the level of food deprivation is regulated by the scout that fed at the food source and by the response of the nestmates to signals performed by the scout inside the nest. In this...

In social insects, rejection of dead nestmates is a common hygienic behaviour that allows colonies to reduce pathogen transmission within the nest. We investigated which orientation processes, chemical cues or individual memory, are used by the common red ant, Myrmica rubra, when it removes dead nestmates far from the nest. Myrmica rubra colonies v...

While food recruitment and foraging have been the subject of many studies, the regulation of the food sharing behaviour remains poorly understood. In this study, we focused on trophallaxis (or mouth-to-mouth food exchange) within a group of worker ants as the first step in characterizing food sharing behaviours. In particular, we wanted to investig...

Tetranychus urticae is a phytophagous mite that forms colonies of several thousand individuals. These mites construct a common web to protect the colony. When plants become overcrowded and food resources become scarce, individuals gather at the plant apex to form a ball composed of mites and their silk threads. This ball is a structure facilitating...

House dust mites (Dermatophagoides pteronyssinus) are widespread in the furniture and mattresses of homes throughout Eurasia. Because human occupation induces wide diurnal fluctuations in temperature and relative humidity, the most favourable locations for mites change constantly and they must migrate repeatedly. Here, we triggered and studied mite...

Honeydew is the keystone on which ant–aphid mutualism is built. The present study investigates how each sugar identified in Aphis fabae Scopoli honeydew acts upon the feeding and the laying of a recruitment trail by scouts of the aphid-tending ant Lasius niger Linnaeus, and thus may enhance collective exploitation by the ant mutualists. The feeding...

In many vertebrates and invertebrates, individuals reared in isolation show biological modi-fications compared with those reared in groups of two of more. The spider mite Tetranychus urticae is characterised by a communal organization and displays some forms of cooperative behaviour (aggregation and common web spinning). To evaluate the potential f...

In the process of seed dispersal by ants (myrmecochory), foragers bring diaspores back to their nest, then eat the elaiosome and usually reject viable seeds outside the nest. Here, we investigate what happens inside the nest, a barely known stage of the myrmecochory process, for two seed species (Viola odorata, Chelidonium majus) dispersed either b...

Exploration allows animals to discover food resources, detect competitors and update their general knowledge of the habitat surroundings. Although the vital importance of exploration, its functional and proximal complexity is often underestimated. In this article, we study the exploring activities of Lasius niger, an aphid-tending ant species that...

We investigated whether the physical castes of the dimorphic ant Pheidole pallidula (Nylander) (Hymenoptera: Formicidae), are involved in determining within-nest activities and how their social investment in everyday tasks is influenced by large changes in the colony's caste ratio. Although the large-headed majors are morphologically distinct from...

In social insects, each behavioural group holds information that may be crucial for the colony's functioning and regulation. We investigated which behavioural group plays the key role in the regulation of recruitment and how it manages to tune the foraging effort according to the level of starvation in the colony. We focused on recruiters and recru...

In the ant species Tetramorium caespitum, communication and foraging patterns rely on group-mass recruitment. Scouts having discovered food recruit nestmates and behave as leaders by guiding groups of recruits to the food location. After a while, a mass recruitment takes place in which foragers follow a chemical trail. Since group recruitment is cr...

Ants collect and disperse seeds that bear an attractive nutritive body called the elaiosome. In mesic habitats, many myrmecochorous plant species have elaiosomes that are usually soft and desiccation-sensitive. The aim of this study was to link the desiccation rate of two species of seeds (Chelidonium majus and Viola odorata) to the seed-removing b...

Nest building in social insects is among the collective processes that show highly conservative features such as basic modules (chambers and galleries) or homeostatic properties. Although ant nests share common characteristics, they exhibit a high structural variability, of which morphogenesis and underlying mechanisms remain largely unknown. We co...

In group living, species spatial distribution results from responses to environmental heterogeneity and/or mutual interactions between individuals. These mutual interactions can be regulated by genetic and/or epigenetic factors. In this study, we focus on genetic factors and investigate how the spatial distribution of some individuals colonizing a...

In the absence of complex communication and a global knowledge of the environment, cockroaches are able to assess the availability of resources and to reach a consensual decision: the group aggregates in a single resting site. We show that the aggregation dynamics and the collective shelter selection of cockroaches are influenced by their social co...

The cuticular hydrocarbons (CHCs) of the ant Lasius niger are described. We observe a high local colony specificity of the body cuticular profile as predicted for a monogynous and multicolonial species. The CHCs show a low geographical variation among different locations in France. The CHCs on the legs also are colony specific, but their relative q...

Although group effect and collective decisions have been described in many insect species, the behavioral mechanisms involved in the process remain poorly documented at the individual level. We examined how individual behavior depends on the environmental context and we precisely characterized the behavioral rules leading to settlement of individua...

The decision for a Lasius niger forager to lay a chemical trail and launch recruitment to a food source is governed by an internal individual threshold. The value of this threshold triggering chemical communication is not set by the maximal capacity of the crop. Actually, trail-laying ants are still able to drink additional food encountered on thei...

Tetranychus urticae (Acari: Tetranychidae) is a phytophagous mite that forms colonies of several thousand individuals. Like spiders, every individual produces abundant silk strands and is able to construct a common web for the entire colony. Despite the importance of this silk for the biology of this worldwide species, only one previous study sugge...

Aphid – ant mutualism: an outdoor study of the benefits for Aphis fabae. Aphid – ant relationships are common examples of mutualism. Aphids are indeed submitted to predation and therefore require protection, while ants are continuously looking for new sugar sources. The present work aimed to study the benefits that a mutualistic relationship with L...

Aphid - ant relationships are common examples of mutualism. Aphids are indeed submitted to predation and therefore require protection, while ants are continuously looking for new sugar sources. The present work aimed to study the benefits that a mutualistic relationship with Lasius niger (Hymenoptera, Formicidae) could bring to the black bean aphid...

This chapter compares collective decisions in hives and in ant nests by relating the properties of recruiting signals to the foraging strategies displayed by these two insect societies. It describes the main positive and negative feedbacks that help foragers self-regulate their activities according to environmental constraints and opportunities. Ev...

Seed dispersal by ants (i.e. myrmecochory) is usually considered as a mutualism: ants feed on nutritive bodies, called elaiosomes, before rejecting and dispersing seeds in their nest surroundings. While mechanisms of plant dispersal in the field are well documented, the behaviour of the ant partner was rarely investigated in details. Here, we compa...

Ant colonies that undergo long starvation periods have to tune their exploratory and foraging responses to face their food needs. Although the number of foragers is known to increase with food deprivation in the ant Lasius niger, such enhanced food exploitation is not related to a more intense recruitment by successful scouts. We thus suggest that...

Collective behavior based on self-organization has been shown in group-living animals from insects to vertebrates. These findings have stimulated engineers to investigate approaches for the coordination of autonomous multirobot systems based on self-organization. In this experimental study, we show collective decision-making by mixed groups of cock...

Larvae of the sawfly Arge (Hymenoptera, Argidae) are exposed to predators such as ants. Their defence mechanisms, which have been almost unstudied, were investigated by behavioural observations coupled to a morphological approach and by testing the bioactivity of several body parts. Arge larvae raised their abdomen when contacted by Myrmica rubra w...

The spatial distribution of individuals is an important subject in many fields because it conditions the levels of interactions among individuals, and more generally the structuring as well as the organization of populations. Increase in density of individuals in a given area can be induced by environmental stimuli and/or by interactions among indi...

The spatial distribution of individuals is an important subject in many fields because it conditions the levels of interactions among individuals, and more generally the structuring as well as the organization of populations. Increase in density of individuals in a given area can be induced by environmental stimuli and/or by interactions among indi...

Collective behavior based on self-organization has been shown in group-living animals from insects to vertebrates. These findings have stimulated engineers to investigate approaches for the coordination of autonomous multirobot systems based on self-organization. In this experimental study, we show collective decision-making by mixed groups of cock...

The decision for an ant forager to launch recruitment is governed by an internal response threshold. Here, we demonstrate that this threshold (the desired volume) triggering trail-laying increases under starvation. As a consequence, highly starved foragers lay a recruitment trail and bring back to the nest higher quantities of food from large unlim...

In mixed societies of robots and cockroaches, several insect-like- robot (Insbot) and animals interact in order to perform collective decision- making. Many gregarious species are able to collectively select a resting site without any leadership. The key process is based on the modulation of the probability of leaving the shelter according to the t...