scholarly journals The parasite's long arm: a tapeworm parasite induces behavioural changes in uninfected group members of its social host

2015 ◽  
Vol 282 (1819) ◽  
pp. 20151473 ◽  
Author(s):  
Sara Beros ◽  
Evelien Jongepier ◽  
Felizitas Hagemeier ◽  
Susanne Foitzik
Keyword(s):  
Social Insects ◽  
Anomalous Behaviour ◽  
Ant Colonies ◽  
Phenotypic Changes ◽  
Flight Response ◽  
Behavioural Changes ◽  
Colony Fitness ◽  
Group Members ◽  
Temnothorax Nylanderi

Parasites can induce alterations in host phenotypes in order to enhance their own survival and transmission. Parasites of social insects might not only benefit from altering their individual hosts, but also from inducing changes in uninfected group members. Temnothorax nylanderi ant workers infected with the tapeworm Anomotaenia brevis are known to be chemically distinct from nest-mates and do not contribute to colony fitness, but are tolerated in their colonies and well cared for. Here, we investigated how tapeworm- infected workers affect colony aggression by manipulating their presence in ant colonies and analysing whether their absence or presence resulted in behavioural alterations in their nest-mates. We report a parasite-induced shift in colony aggression, shown by lower aggression of uninfected nest-mates from parasitized colonies towards conspecifics, potentially explaining the tolerance towards infected ants. We also demonstrate that tapeworm-infected workers showed a reduced flight response and higher survival, while their presence caused a decrease in survival of uninfected nest-mates. This anomalous behaviour of infected ants, coupled with their increased survival, could facilitate the parasites' transmission to its definitive hosts, woodpeckers. We conclude that parasites exploiting individuals that are part of a society not only induce phenotypic changes within their individual hosts, but in uninfected group members as well.

scholarly journals Major Evolutionary Transitions in Social Insects, the Importance of Worker Sterility and Life History Trade-Offs

2021 ◽  
Vol 9 ◽  
Author(s):  
Abel Bernadou ◽  
Boris H. Kramer ◽  
Judith Korb
Keyword(s):  
Life History ◽  
Social Insects ◽  
Division Of Labour ◽  
Evolutionary Transitions ◽  
Individual Level ◽  
Individual Fitness ◽  
Trade Offs ◽  
Group Members ◽  
The Individual ◽  
Worker Sterility

The evolution of eusociality in social insects, such as termites, ants, and some bees and wasps, has been regarded as a major evolutionary transition (MET). Yet, there is some debate whether all species qualify. Here, we argue that worker sterility is a decisive criterion to determine whether species have passed a MET (= superorganisms), or not. When workers are sterile, reproductive interests align among group members as individual fitness is transferred to the colony level. Division of labour among cooperating units is a major driver that favours the evolution of METs across all biological scales. Many METs are characterised by a differentiation into reproductive versus maintenance functions. In social insects, the queen specialises on reproduction while workers take over maintenance functions such as food provisioning. Such division of labour allows specialisation and it reshapes life history trade-offs among cooperating units. For instance, individuals within colonies of social insects can overcome the omnipresent fecundity/longevity trade-off, which limits reproductive success in organisms, when increased fecundity shortens lifespan. Social insect queens (particularly in superorganismal species) can reach adult lifespans of several decades and are among the most fecund terrestrial animals. The resulting enormous reproductive output may contribute to explain why some genera of social insects became so successful. Indeed, superorganismal ant lineages have more species than those that have not passed a MET. We conclude that the release from life history constraints at the individual level is a important, yet understudied, factor across METs to explain their evolutionary success.

scholarly journals Optimality in a partitioned task performed by social insects

2008 ◽  
Vol 4 (6) ◽  
pp. 627-629 ◽  
Author(s):  
Martin Burd ◽  
Jerome J Howard
Keyword(s):  
Social Insects ◽  
Social Insect ◽  
Leaf Tissue ◽  
Leaf Fragment ◽  
Ant Colonies ◽  
Tissue Processing ◽  
Leaf Cutting ◽  
Laboratory Colonies ◽  
Atta Colombica ◽  
Behavioural Adaptations

Biologists have long been aware that adaptations should not be analysed in isolation from the function of the whole organism. Here, we address the equivalent issue at the scale of a social insect colony: the optimality of component behaviours in a partitioned sequence of tasks. In colonies of Atta colombica , a leaf-cutting ant, harvested leaf tissue is passed from foragers to nest workers that distribute, clean, shred and implant the tissue in fungal gardens. In four laboratory colonies of A. colombica , we found that the highest colony-wide rate of leaf tissue processing in the nest was achieved when leaf fragment sizes were suboptimal for individual delivery rate by foragers. Leaf-cutting ant colonies appear to compromise the efficiency of collecting leaf tissue in order to increase their ability to handle the material when it arrives in the nest. Such compromise reinforces the idea that behavioural adaptations, like adaptations in general, must be considered within the context of the larger entity of which they are a part.

scholarly journals Dear Enemy Phenomenon in the Ant Ectatomma brunneum (Formicidae: Ectatomminae): Chemical Signals Mediate Intraspecific Agressive Interactions

Sociobiology ◽  
2019 ◽  
Vol 66 (2) ◽  
pp. 218
Author(s):  
Márlon César Pereira ◽  
Ellen Liciane Barbosa Firmino ◽  
Rafaella Caroline Bernardi ◽  
Luan Dias Lima ◽  
Ingrid De Carvalho Guimarães ◽  
...  
Keyword(s):  
Cuticular Hydrocarbon ◽  
Hydrocarbon Composition ◽  
Chemical Signals ◽  
Behavioral Strategies ◽  
Intraspecific Interactions ◽  
Ant Colonies ◽  
Dear Enemy ◽  
Ant Behavior ◽  
Dear Enemy Phenomenon ◽  
Group Members

The integrity of ant colonies depends exclusively on social relationships between their individuals, especially the ability of communication between group members, which is mainly mediated through chemical signals. Another important feature of ant behavior is territory defense, since they need to gather large amounts of food to feed their larvae, males and breeding females. Thereby, ants might display behavioral strategies to defend their territories from intruders. Here we investigated whether Ectatomma brunneum displays the Dear Enemy Phenomenon, what is the relationship between Cuticular Hydrocarbon composition and levels of aggression during their intraspecific interactions and which compounds and/or classes of compounds might be the most important to modulate the level of aggression. To test our hypothesis, we evaluated the levels of aggression through behavioral observations during interactions between 23 pairs of colonies nested in two distinct sites at varied distances. Then, we analyzed the cuticular chemical profile of the individuals involved in the interactions, and compared these results with the levels of aggression displayed between colonies tested. The results allow us to confirm our hypothesis that the DEP occurs in E. brunneum. The higher tolerance between closer colonies can be explained due to their kinship level in addition to sharing the same microhabitats. The results also showed there are significant differences in CHCs profiles, especially between colonies nested at relatively greater distances, and it is likely that differences in content of some branched alkanes are the most important to establish these differences and, therefore, the levels of aggression during the interactions.

scholarly journals Nest Entrances, Spatial Fidelity, and Foraging Patterns in the Red Ant Myrmica rubra: A Field and Theoretical Study

Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 317 ◽  
Author(s):  
Marine Lehue ◽  
Claire Detrain ◽  
Bertrand Collignon
Keyword(s):  
Spatial Distribution ◽  
Social Insects ◽  
Theoretical Study ◽  
High Fidelity ◽  
Nest Architecture ◽  
Myrmica Rubra ◽  
Foraging Patterns ◽  
Ant Colonies ◽  
Agent Model ◽  
Multi Agent

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 investigated in the field how the number of nest entrances impacted the foraging dynamics of Myrmica rubra ant colonies. We located the nest entrances where recruitment occurred towards sugar feeders placed in their surroundings. The nests showed one or multiple entrance(s) aggregated in clusters spaced by at least 15 cm. Foragers from colonies with two clusters of entrances were distributed more homogeneously among the feeders than those of colonies with one cluster. In addition, foragers always returned to the first discovered feeder and demonstrated a high fidelity to their original entrance. Finally, a multi-agent model highlighted that additional entrances and clusters of entrances delayed the mobilisation of workers but favoured the simultaneous exploitation of several sources, which was further enhanced by the spatial fidelity of foragers. Multiple nest entrances seem to be a way for medium-sized colonies to benefit from advantages conferred by polydomy while avoiding associated costs to maintain social cohesion.

scholarly journals Emergence of intercolonial variation in termite shelter tube patterns and prediction of its underlying mechanism

2015 ◽  
Vol 2 (11) ◽  
pp. 150360 ◽  
Author(s):  
Nobuaki Mizumoto ◽  
Kazuya Kobayashi ◽  
Kenji Matsuura
Keyword(s):  
Social Insects ◽  
Environmental Conditions ◽  
Lattice Model ◽  
Underlying Mechanism ◽  
Self Organization ◽  
Two Dimensional ◽  
Dimensional Lattice ◽  
Group Members ◽  
Collective Building ◽  
Number Of Individuals

Building behaviours occur in various organisms from bacteria to humans. Social insects build various structures such as large nests and underground galleries, achieved by self-organization. Structures built by social insects have recently been demonstrated to vary widely in size and shape within a species, even under the same environmental conditions. However, little is known about how intraspecific variation in structures emerges from collective behaviours. Here we show that the colony variation of structures can be generated by simply changing two behavioural parameters of group members, even with the same building algorithm. Our laboratory experiment of termite shelter tube construction demonstrated clear intercolonial variation, and a two-dimensional lattice model showed that it can be attributed to the extent of positive feedback and the number of individuals engaged in building. This study contributes to explaining the great diversity of structures emerging from collective building in social insects.

scholarly journals Sources of intraspecific variation in the collective tempo and synchrony of ant societies

2019 ◽  
Vol 30 (6) ◽  
pp. 1682-1690
Author(s):  
Grant Navid Doering ◽  
Kirsten A Sheehy ◽  
James L L Lichtenstein ◽  
Brian Drawert ◽  
Linda R Petzold ◽  
...  
Keyword(s):  
Intraspecific Variation ◽  
Social Insects ◽  
Activity Cycle ◽  
Behavioral Differences ◽  
Short Term ◽  
Ant Colonies ◽  
Collective Activity ◽  
Worker Activity ◽  
Animal Societies

Abstract Populations of independently oscillating agents can sometimes synchronize. In the context of animal societies, conspicuous synchronization of activity is known in some social insects. However, the causes of variation in synchrony within and between species have received little attention. We repeatedly assessed the short-term activity cycle of ant colonies (Temnothorax rugatulus) and monitored the movements of individual workers and queens within nests. We detected persistent differences between colonies in the waveform properties of their collective activity oscillations, with some colonies consistently oscillating much more erratically than others. We further demonstrate that colony crowding reduces the rhythmicity (i.e., the consistent timing) of oscillations. Workers in both erratic and rhythmic colonies spend less time active than completely isolated workers, but workers in erratic colonies oscillate out of phase with one another. We further show that the queen’s absence can impair the ability of colonies to synchronize worker activity and that behavioral differences between queens are linked with the waveform properties of their societies.

scholarly journals Social aging: Late-life fitness gains explain the absence of a selection shadow in ants

2021 ◽  
Author(s):  
LM Jaimes Nino ◽  
J. Heinze ◽  
J Oettler
Keyword(s):  
Old Age ◽  
Social Insects ◽  
Late Life ◽  
Apparent Absence ◽  
Ant Colonies ◽  
Adaptive Shift ◽  
Selection Strength ◽  
Selection For ◽  
Iteroparous Species ◽  
Plastic Trait

AbstractA key hypothesis for the occurrence of senescence is a decrease in the selection strength because of low late-life fitness – the so-called selection shadow. However, in social insects, aging is considered a plastic trait and senescence seems to be absent. By life-long tracking of 102 ant colonies, we find that queens increase sexual productivity in late life regardless of their absolute lifespan or worker investment. This indicates a genetically accommodated adaptive shift towards increasingly queen-biased caste ratios over the course of a queens’ life. Furthermore, mortality decreased with age, supporting the hypothesis that aging is adaptive. We argue that selection for late life reproduction diminishes the selection shadow of old age and leads to the apparent absence of senescence in ants, in contrast to most iteroparous species.

scholarly journals Extreme lifespan extension in tapeworm-infected ant workers

2021 ◽  
Vol 8 (5) ◽  
pp. 202118
Author(s):  
Sara Beros ◽  
Anna Lenhart ◽  
Inon Scharf ◽  
Matteo Antoine Negroni ◽  
Florian Menzel ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Social Insects ◽  
Lipid Content ◽  
Social Care ◽  
Separate Experiment ◽  
Lifespan Extension ◽  
Young Workers ◽  
Chemical Profile ◽  
Temnothorax Nylanderi ◽  
Tapeworm Infection

Social insects are hosts of diverse parasites, but the influence of these parasites on phenotypic host traits is not yet well understood. Here, we tracked the survival of tapeworm-infected ant workers, their uninfected nest-mates and of ants from unparasitized colonies. Our multi-year study on the ant Temnothorax nylanderi, the intermediate host of the tapeworm Anomotaenia brevis, revealed a prolonged lifespan of infected workers compared with their uninfected peers. Intriguingly, their survival over 3 years did not differ from those of (uninfected) queens, whose lifespan can reach two decades. By contrast, uninfected workers from parasitized colonies suffered from increased mortality compared with uninfected workers from unparasitized colonies. Infected workers exhibited a metabolic rate and lipid content similar to young workers in this species, and they received more social care than uninfected workers and queens in their colonies. This increased attention could be mediated by their deviant chemical profile, which we determined to elicit more interest from uninfected nest-mates in a separate experiment. In conclusion, our study demonstrates an extreme lifespan extension in a social host following tapeworm infection, which appears to enable host workers to retain traits typical for young workers.

Behavioural changes and flight response of a mosquito (Culicidae) and an earthworm (Lumbricidae), respectively, after exposure to imidacloprid

Ecotoxicology ◽  
2022 ◽  
Author(s):  
Palesa Andile Adrena Tsotesti ◽  
Simangele Sandra Mazibuko ◽  
Ngitheni Winnie-Kate Nyoka ◽  
Sanele Michelle Mnkandla ◽  
Tanya Fouché ◽  
...  
Keyword(s):  
Flight Response ◽  
Behavioural Changes
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