Nicolas Châline

University of São Paulo | USP · Department of Experimental Psychology

In social species, the phenotype and fitness of an individual depend in part on the genotype of its social partners. However, how these indirect genetic effects affect genotype fitness in competitive situations is poorly understood in animal societies. We therefore studied phenotypic plasticity and fitness of two clones of the ant Cerapachys biroi...

Restricted reproduction is traditionally posited as the defining feature of eusocial insect workers. The discovery of worker reproduction in foreign colonies challenges this view and suggests that workers' potential to pursue selfish interests may be higher than previously believed. However, whether such reproductive behaviour truly relies on a rep...

In insect societies, worker policing controls genetic conflicts between individuals and increases colony efficiency [1-6]. However, disentangling relatedness from colony-level effects is usually impossible [7-11]. We studied policing in the parthenogenetic ant Cerapachys biroi, where genetic conflicts are absent due to clonality [12, 13] and reprod...

Context-dependent decision-making conditions individual plasticity and is an integrant part of alternative reproductive strategies. In eusocial Hymenoptera (ants, bees and wasps), the discovery of worker reproductive parasitism recently challenged the view of workers as a homogeneous collective entity and stressed the need to consider them as auton...

With urbanization increasing globally, conservation ecologists need to characterize the functioning of ecosystems embedded in urban landscapes. Ubiquitous and hyperdiverse, ants are an ideal model taxon for this purpose. Here we compared diversity, richness, and abundance of ants in a forest fragment and a green urban area within the City of São Pa...

Social animals often coordinate behavioural activities for the gathering, maintenance and protection of resources. In eusocial insects, morphological and/or behavioural heterogeneity among worker caste allows division of labour and, in some instances, the specialization of individuals in specific tasks. In leaf-cutting ants (genus Atta), the divisi...

Meliponine bees use chemical-based nestmate discrimination to protect their colonies from unrelated intruders. However, species from the Amazon basin are relatively poorly known from this perspective. Here, we investigated Melipona paraensis nestmate discrimination in different contexts (nests vs. neutral arenas), testing aggression in bees facing...

While pillaging the brood of other ant colonies, Eciton army ants accumulate prey in piles, or caches, along their foraging trails. Widely documented, these structures have historically been considered as by-products of heavy traffic or aborted relocations of the ants' temporary nest, or bivouac. However, we recently observed that caches of the hoo...

While pillaging the brood of other ant colonies, Eciton army ants accumulate prey in piles, or caches, along their foraging trails. Widely documented, these structures have historically been considered as byproducts of heavy traffic or aborted relocations of the ants’ temporary nest, or bivouac. However, we recently observed that caches of the hook...

Ants show collective and individual behavioural flexibility in their response to immediate context, choosing for example between different foraging strategies. In Pachycondyla striata, workers can forage solitarily or recruit and guide nestmates to larger food sources through tandem running. Although considered more ancestral and less efficient tha...

O forragemento pode ocorrer de forma solitária ou envolver recrutamento por tandem running.

While pillaging brood of other social insects, Eciton army ants often accumulate prey in piles (or caches) along their foraging trails. Descriptions scattered throughout the past 100 years link this behavior to foraging-related migration. However, no empirical work has yet investigated its adaptive value. Here we asked whether caches facilitate pre...

Judgment bias tests have become an important tool in the assessment of animals’ affective states. Subjects are first trained to discriminate between two cues associated with a positive and a less-positive outcome. After successful training, they are confronted with an ambiguous cue, and responses are used for judgment bias assessment. In spatial se...

The army ant Eciton rapax still little known in your natural history. The nesting habits of E. rapax are still poorly studied, being an important gap for understanding the ecology of this species. Our study recorded and described E. rapax nesting sites. The study was carried out in a region of Amazon primary forest, in dry land areas, in Bragança C...

In social groups, competition often gives rise to conflicts, which are regulated through a variety of mechanisms. In several social insect species, the conflict for male production that takes place between workers after queen loss, is regulated through the establishment of a reproductive hierarchy. A recent study of Neoponera apicalis showed that w...

Various organisms emit malodorous secretions against competitors, and the potential use of these secretions in pest management should be investigated. For example, some ant species feed on similar resources as dung beetles, which might have led to counter chemical defences in dung beetles. We tested whether pygidial secretions of the dung beetle Ca...

In the book The Insect Societies, Wilson proposed categories of sociality that were presented as a landmark unification of terminology in the study of social behavior. Since then, many new behavioral patterns have been described, but they could not be fitted into any of the available categories, undermining the consensus around that well-establishe...

Potential negative effects of the synthetic veterinary pharmaceutical, Ivermectin, on non-target fauna have generated a search for less-toxic alternatives. Thus, Neem plant extract (Azadirachta indica A. Juss) has been used as a natural alternative to replace Ivermectin worldwide. However, little is known about the effects of this natural veterinar...

Potential negative effects of the synthetic veterinary pharmaceutical, Ivermectin, on non-target fauna have generated a search for less-toxic alternatives. Thus, Neem plant extract ( Azadirachta indica A. Juss) has been used as a natural alternative to replace Ivermectin worldwide. However, little is known about the effects of this natural veterina...

The dung roller beetle Canthon smaragdulus (Scarabaeinae) has a pair of pygidial glands whose secretions have different functions. However, the factors influencing the production of pygidial secretions in these dung beetles are not known. This study is the first to evaluate differences in the amount of pygidial secretions produced by C. smaragdulus...

As funções ecológicas realizadas pelos besouros escarabeíneos, ou “rola-bostas”, foram estudadas nos três principais sistemas de uso do solo da região do Caparaó Capixaba: lavouras de café, pastagens e fragmentos florestais. Nos ambientes de florestas foi observada uma maior quantidade média de fezes enterradas em relação aos cafezais, já nas pasta...

1. The ecological success of social insects lies in their ability to prevent the exploitation of colony resources by competitors or parasites. Nestmate recognition is therefore of crucial importance in maintaining the integrity of the colony. Furthermore, inter-colony competitive relationships are often complex, as many species discriminate between...

It is well known that age influences organism mobility. This was demonstrated in vertebrates (such as mammals and birds) but has been less studied in invertebrates with the exception of Drosophila and the nematode Caenorhabditis elegans. Here we studied the influence of age on the mobility of the orb-weaving spider Zygiella x-notata during web cons...

Communication and behaviour in poneromorph ants - Understanding the complex mechanisms underlying the evolution of social behaviour is a fundamental question in ethology. Inclusive fitness theory allows precise predictions on the occurrence of both cooperation and conflicts in social groups, but at a proximal level various mechanisms have evolved i...

Communication and behaviour in poneromorph ants - Understanding the complex mechanisms underlying the evolution of social behaviour is a fundamental question in ethology. Inclusive fitness theory allows precise predictions on the occurrence of both cooperation and conflicts in social groups, but at a proximal level various mechanisms have evolved i...

All individuals in social insect colonies benefit from being informed about the presence and fertility state of reproducers. This allows the established reproductive individuals to maintain their reproductive monopoly without the need for physical control, and the non-reproductive individuals to make appropriate reproductive choices. Here, we studi...

Communication and behaviour in poneromorph ants - Understanding the complex mechanisms underlying the evolution of social behaviour is a fundamental question in ethology. Inclusive fitness theory allows precise predictions on the occurrence of both cooperation and conflicts in social groups, but at a proximal level various mechanisms have evolved i...

Aging is often associated with reduced behavioral performance such as decreased locomotion or food consumption, related to a deterioration in physiological functions. In orb-web spiders, webs are used to capture prey and aging can affect web-building behavior and web structure. Here, we investigated the effect of aging on prey capture in the orb-we...

Dominance hierarchies allow group-living animals to regulate the partitioning of reproduction, but the recognition systems underlying dominance interactions remain equivocal. Individual recognition, a cognitively complex recognition system, is often posited as an important mechanism for the regulation of linear dominance hierarchies because of its...

Although cuticular hydrocarbons (CHCs) have received much attention from biologists because of their important role in insect communication, few studies have addressed the chemical ecology of clonal species of eusocial insects. In this study we investigated whether and how differences in CHCs relate to the genetics and reproductive dynamics of the...

The impact of social parasites on their hosts' fitness is a strong selective pressure that can lead to the evolution of adapted defence strategies. Guarding the nest to prevent the intrusion of parasites is a widespread response of host species. If absolute rejection of strangers provides the best protection against parasites, more fine-tuned strat...

We previously reported the existence of a unique policing system in the clonal ant Cerapachys biroi, where individuals that fail to synchronize to the colony reproductive dynamics and reproduce without control are recognized and executed by their nestmates. These executions help maintain the alternation of reproductive and foraging phases, a colony...

Background Social parasitism is an important selective pressure for social insect species. It is particularly the case for the hosts of dulotic (so called slave-making) ants, which pillage the brood of host colonies to increase the worker force of their own colony. Such raids can have an important impact on the fitness of the host nest. An arms rac...

Identified cuticular hydrocarbons of species’ chemical profiles. Mean percentages (±S.D) of the different compounds in the chemical profiles of M. ravouxi (M. rav), T. unifasciatus from Anduze (T. uni_And) and Fontainebleau (T. uni_Font), T. rabaudi (T. rab) and T. nylanderi from Anduze (T. nyl_And) and Fontainebleau (T. nyl_Font). Compounds were i...

Distances between centroids. Distance between centroids for the chemical profiles of populations of M. ravouxi, T. nylanderi from Anduze and Fontainebleau, T. rabaudi and T. unifasciatus from Anduze and Fontainebleau.

Ageing is known to induce profound effects on physiological functions but only a few studies have focused on its behavioural alterations. Orb-webs of spiders, however, provide an easily analysable structure, the result of complex sequences of stereotypical behaviours that are particularly relevant to the study of ageing processes. We chose the orb...

Social parasites exploit complete societies, on which they are dependent. In ants, slave-making species invade, exploit and raid host colonies, impacting their survival and exerting powerful selection pressure on their host species. Recent studies suggest that host ant species may develop a parasite brood intolerance, which could be the first step...

Behavioural bioassays have shown that worker honeybees can distinguish between worker-laid and queen-laid eggs. By eating worker-laid eggs, nest-mate workers pre-vent each other from reproducing, a behaviour known as worker policing. However, the recognition cue used by worker honeybees to discriminate between worker-laid and queen-laid eggs remain...

Slave-making ants exploit the worker force of host colonies permanently and have to make recurrent raids in order to replenish the slave’s stock. Some of these parasite species exploit different host species and few studies so far have been devoted to host species recognition mechanisms. Here, we tried to determine if opportunist slave-making ants...

Caste differentiation leading to reproductive division of labor is the hallmark of insect societies. Insect colonies typically contain mated queens that reproduce and workers with reduced fertility that undertake the tasks required for colony maintenance and development. Despite the prediction that the proportion of morphological castes should vary...

Disease is one of the main factors driving both natural and artificial selection. It is a particularly important and increasing threat to the managed honeybee colonies, which are vital in crop pollination. Artificial selection for disease-resistant honeybee genotypes has previously only been carried out at the colony-level, that is, by using queens...

The question of the occurrence of nepotism in insect societies is central to inclusive fitness theory. Here we investigated the existence of nepotism in the facultative polygynous ant Ectatomma tuberculatum because various characteristics of this species may have favored the evolution of nepotistic behavior toward queens. We thus studied worker–que...

In eusocial Hymenoptera, the ability of workers to reproduce is a cause of conflict, both between the queen and workers and among workers. Reproductive decisions by workers depend on parameters such as colony size (which reduces the cost of selfish reproduction for the colony) or queen fertility. Indeed, queen signals inhibit reproduction from work...

Analyzed microsatellite sequences characteristics and variability. N = number of individuals, Na = number of polymorph alleles and Ho = mean heterozygosis rate observed for each locus in the R. lucifugus and R. l. corsicus colonies.

List of primers and PCR profiles used for amplification and sequencing.

Although much research has been carried out into European Reticulitermes taxonomy in recent years, there is still much discussion about phylogenetic relationships. This study investigated the evolution from intra- to interspecific phylogeny in the island subspecies Reticulitermes lucifugus corsicus and threw new light on this phenomenon. An integra...

Nestmate recognition is a key feature of social insects, as it preserves colony integrity. However, discrimination of non-nestmates and nestmate recognition mechanisms are highly variable according to species and social systems. Here, we investigated the intraspecific level of aggression in the facultative polygynous and polydomous ant, Ectatomma t...

Pheromone trails are self-organized processes, where colony-level behaviour emerges from the activity of many individuals responding to local information. The Pharaoh's ant is an important model species for investigating pheromone trails. Here we show that Pharaoh's ant foragers mark with trail pheromones, using their stinger, on both the outward a...

Division of labor, the specialization of workers on different tasks, largely contributes to the ecological success of social insects [1, 2]. Morphological, genotypic, and age variations among workers, as well as their social interactions, all shape division of labor [1-12]. In addition, individual experience has been suggested to influence workers...

We characterized 20 microsatellite loci in the long-tailed tit, Aegithalos caudatus. Polymorphic loci were identified by testing 114 loci that had been originally isolated in other avian species. The loci were characterized in 23–163 unrelated long-tailed tits from a British population and displayed between two and 42 alleles, with observed heteroz...

ABStrACt Survival and caste differentiation were observed under controlled con-ditions in orphaned experimental colonies of the subterranean termites Reticulitermes grassei and R. santonensis. Worker colonies had different sizes (30, 50, 100, 200 and 300); after 12 and 32 months the differentiation of colony members in other castes was observed. tw...

In queen-right honeybee colonies workers detect and eat the vast majority of worker-laid eggs, a behaviour known as worker policing. However, if a colony becomes permanently queen-less then up to 25% of the worker population develops their ovaries and lay eggs, which are normally reared into a final batch of males. Ovary development in workers is a...

Honey bee males and queens mate in mid air and can fly many kilometres on their nuptial flights. The conservation of native honey bees, such as the European black bee (Apis mellifera mellifera), therefore, requires large isolated areas to prevent hybridisation with other subspecies, such as A. m. ligustica or A. m. carnica, which may have been intr...

In social insect colonies, recognition of nestmates, kinship, caste and reproductive status is crucial both for individuals and for the colony. The recognition cues used are thought to be chemical, with the hydrocarbons found on the cuticle of insects often cited as being particularly important. However, in honeybees (Apis mellifera) the role of cu...

Nepotism is an important potential conflict in animal societies. However, clear evidence of nepotism in the rearing of queens in social insects is limited and controversial. In the honey bee, Apis mellifera, multiple mating by queens leads to the presence of many patrilines within each colony. When the colonies reproduce through swarming, workers r...

Despite worker-laid and queen-laid honeybee eggs having significantly different hydrocarbon profiles, bioassays and chemical supplementation studies show that changing the hydrocarbon profile does not affect egg identity. Furthermore, full-sized eggs that are tested just before being laid or just after being laid have similar hydrocarbon patterns b...

In honeybees, worker policing via egg eating enforces functional worker sterility in colonies with a queen and brood. It is thought that queens mark their eggs with a chemical signal, indicating that their eggs are queen-laid. Worker-laid eggs lack this signal and are, therefore, eaten by policing workers. Anarchistic worker honeybees have been hyp...

In queenright colonies of Apis mellifera, worker policing normally eliminates worker-laid eggs thereby preventing worker reproduction. However, in queenless colonies that have failed to rear a replacement queen, worker reproduction is normal. Worker policing is switched off, many workers have active ovaries and lay eggs, and the colony rears a last...

DNA sampling of insects frequently relies upon lethal or invasive methods. Because insect colonies contain numerous workers it is often possible to destructively sample workers for genetic analysis. However, this is not possible if queens or workers must remain alive after sampling. Neither is it possible to remove an entire leg, wing or other appe...

In many animals reproductive success is determined after insemination by the interaction of male and female processes. While sperm competition is reasonably well understood in some taxa, other processes, such as cryptic female choice and differential early embryo mortality resulting from genetic incompatibilities, are less well understood. The rela...