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Animal Cognition Jun 2022Quantitative information is omnipresent in the world and a wide range of species has been shown to use quantities to optimize their decisions. While most studies have...
Quantitative information is omnipresent in the world and a wide range of species has been shown to use quantities to optimize their decisions. While most studies have focused on vertebrates, a growing body of research demonstrates that also insects such as honeybees possess basic quantitative abilities that might aid them in finding profitable flower patches. However, it remains unclear if for insects, quantity is a salient feature relative to other stimulus dimensions, or if it is only used as a "last resort" strategy in case other stimulus dimensions are inconclusive. Here, we tested the stingless bee Trigona fuscipennis, a species representative of a vastly understudied group of tropical pollinators, in a quantity discrimination task. In four experiments, we trained wild, free-flying bees on stimuli that depicted either one or four elements. Subsequently, bees were confronted with a choice between stimuli that matched the training stimulus either in terms of quantity or another stimulus dimension. We found that bees were able to discriminate between the two quantities, but performance differed depending on which quantity was rewarded. Furthermore, quantity was more salient than was shape. However, quantity did not measurably influence the bees' decisions when contrasted with color or surface area. Our results demonstrate that just as honeybees, small-brained stingless bees also possess basic quantitative abilities. Moreover, invertebrate pollinators seem to utilize quantity not only as "last resort" but as a salient stimulus dimension. Our study contributes to the growing body of knowledge on quantitative cognition in invertebrate species and adds to our understanding of the evolution of numerical cognition.
Topics: Animals; Bees; Cognition; Flowers
PubMed: 34812987
DOI: 10.1007/s10071-021-01581-6 -
Scientific Reports May 2023Formic acid is the main component of the ant's major weapon against enemies. Being mainly used as a chemical defense, the acid is also exploited for recruitment and...
Formic acid is the main component of the ant's major weapon against enemies. Being mainly used as a chemical defense, the acid is also exploited for recruitment and trail marking. The repelling effect of the organic acid is used by some mammals and birds which rub themselves in the acid to eliminate ectoparasites. Beekeepers across the world rely on this effect to control the parasitic mite Varroa destructor. Varroa mites are considered the most destructive pest of honey bees worldwide and can lead to the loss of entire colonies. Formic acid is highly effective against Varroa mites but can also kill the honeybee queen and worker brood. Whether formic acid can also affect the behavior of honey bees is unknown. We here study the effect of formic acid on sucrose responsiveness and cognition of honey bees treated at different live stages in field-relevant doses. Both behaviors are essential for survival of the honey bee colony. Rather unexpectedly, formic acid clearly improved the learning performance of the bees in appetitive olfactory conditioning, while not affecting sucrose responsiveness. This exciting side effect of formic acid certainly deserves further detailed investigations.
Topics: Bees; Animals; Ants; Cognition; Drug-Related Side Effects and Adverse Reactions; Mitochondrial ADP, ATP Translocases; Sucrose; Varroidae; Mammals
PubMed: 37225773
DOI: 10.1038/s41598-023-35540-7 -
Proceedings of the National Academy of... Mar 2021
Topics: Humans; Metagenome; Metagenomics; Microbiota; Sociobiology
PubMed: 33593943
DOI: 10.1073/pnas.2100934118 -
Heredity Feb 2021Cuticular hydrocarbons (CHCs) have two fundamental functions in insects. They protect terrestrial insects against desiccation and serve as signaling molecules in a wide... (Review)
Review
Cuticular hydrocarbons (CHCs) have two fundamental functions in insects. They protect terrestrial insects against desiccation and serve as signaling molecules in a wide variety of chemical communication systems. It has been hypothesized that these pivotal dual traits for adaptation to both desiccation and signaling have contributed to the considerable evolutionary success of insects. CHCs have been extensively studied concerning their variation, behavioral impact, physiological properties, and chemical compositions. However, our understanding of the genetic underpinnings of CHC biosynthesis has remained limited and mostly biased towards one particular model organism (Drosophila). This rather narrow focus has hampered the establishment of a comprehensive view of CHC genetics across wider phylogenetic boundaries. This review attempts to integrate new insights and recent knowledge gained in the genetics of CHC biosynthesis, which is just beginning to incorporate work on more insect taxa beyond Drosophila. It is intended to provide a stepping stone towards a wider and more general understanding of the genetic mechanisms that gave rise to the astonishing diversity of CHC compounds across different insect taxa. Further research in this field is encouraged to aim at better discriminating conserved versus taxon-specific genetic elements underlying CHC variation. This will be instrumental in greatly expanding our knowledge of the origins and variation of genes governing the biosynthesis of these crucial phenotypic traits that have greatly impacted insect behavior, physiology, and evolution.
Topics: Animals; Drosophila; Hydrocarbons; Insecta; Phenotype; Phylogeny
PubMed: 33139902
DOI: 10.1038/s41437-020-00380-y -
Current Biology : CB Jan 2022Solitary foraging insects, such as ants, maintain an estimate of the direction and distance to their starting location as they move away from it, in a process known as...
Solitary foraging insects, such as ants, maintain an estimate of the direction and distance to their starting location as they move away from it, in a process known as path integration. This estimate, commonly known as the "home vector," is updated continuously as the ant moves and is reset as soon as it enters its nest, yet ants prevented from returning to their nest can still use their home vector when released several hours later. This conjunction of fast update and long persistence of the home vector memory does not directly map to existing accounts of short-, mid-, and long-term memory; hence, the substrate of this memory remains unknown. Chill-coma anesthesia has previously been shown to affect associative memory retention in fruit flies and honeybees. We investigate the nature of path integration memory by anesthetizing ants after they have accumulated home vector information and testing if the memory persists on recovery. We show that after anesthesia the memory of the distance ants have traveled is degraded, but the memory of the direction is retained. We also show that this is consistent with models of path integration that maintain the memory in a redundant Cartesian coordinate system and with the hypothesis that chill-coma produces a proportional reduction of the memory, rather than a subtractive reduction or increase of noise. The observed effect is not compatible with a memory based on recurrent circuit activity and points toward an activity-dependent molecular process as the basis of path integration memory.
Topics: Anesthesia; Animals; Ants; Coma; Cues; Desert Climate; Homing Behavior
PubMed: 34852215
DOI: 10.1016/j.cub.2021.11.039 -
STAR Protocols Dec 2023Agent-based models are composed of individual agents coded for traits, such as cooperation and cheating, that interact in a virtual world based on defined rules. Here,...
Agent-based models are composed of individual agents coded for traits, such as cooperation and cheating, that interact in a virtual world based on defined rules. Here, we describe the use of an agent-based model of homologous recombination in bacteria playing a public goods game. We describe steps for software installation, setting model parameters, running and testing models, and visualization and statistical analysis. This protocol is useful in analyses of horizontal gene transfer, bacterial sociobiology, and game theory. For complete details on the use and execution of this protocol, please refer to Lee et al..
Topics: Game Theory; Bacteria
PubMed: 37980566
DOI: 10.1016/j.xpro.2023.102733 -
Current Biology : CB Nov 2018Observations of animals feeding in aggregations are often interpreted as events of social foraging, but it can be difficult to determine whether the animals arrived at...
Observations of animals feeding in aggregations are often interpreted as events of social foraging, but it can be difficult to determine whether the animals arrived at the foraging sites after collective search [1-4] or whether they found the sites by following a leader [5, 6] or even independently, aggregating as an artifact of food availability [7, 8]. Distinguishing between these explanations is important, because functionally, they might have very different consequences. In the first case, the animals could benefit from the presence of conspecifics, whereas in the second and third, they often suffer from increased competition [3, 9-13]. Using novel miniature sensors, we recorded GPS tracks and audio of five species of bats, monitoring their movement and interactions with conspecifics, which could be inferred from the audio recordings. We examined the hypothesis that food distribution plays a key role in determining social foraging patterns [14-16]. Specifically, this hypothesis predicts that searching for an ephemeral resource (whose distribution in time or space is hard to predict) is more likely to favor social foraging [10, 13-15] than searching for a predictable resource. The movement and social interactions differed between bats foraging on ephemeral versus predictable resources. Ephemeral species changed foraging sites and showed large temporal variation nightly. They aggregated with conspecifics as was supported by playback experiments and computer simulations. In contrast, predictable species were never observed near conspecifics and showed high spatial fidelity to the same foraging sites over multiple nights. Our results suggest that resource (un)predictability influences the costs and benefits of social foraging.
Topics: Animal Migration; Animals; Behavior, Animal; Chiroptera; Feeding Behavior; Flight, Animal; Population Density; Population Dynamics; Predatory Behavior; Social Behavior
PubMed: 30393034
DOI: 10.1016/j.cub.2018.09.064 -
Proceedings. Biological Sciences Jun 2023Many social insects display age polyethism: young workers stay inside the nest, and only older workers forage. This behavioural transition is accompanied by genetic and...
Many social insects display age polyethism: young workers stay inside the nest, and only older workers forage. This behavioural transition is accompanied by genetic and physiological changes, but the mechanistic origin of it remains unclear. To investigate if the mechanical demands on the musculoskeletal system effectively prevent young workers from foraging, we studied the biomechanical development of the bite apparatus in leaf-cutter ants. Fully matured foragers generated peak bite forces of around 100 mN, more than one order of magnitude in excess of those measured for freshly eclosed callows of the same size. This change in bite force was accompanied by a sixfold increase in the volume of the mandible closer muscle, and by a substantial increase of the flexural rigidity of the head capsule, driven by a significant increase in both average thickness and indentation modulus of the head capsule cuticle. Consequently, callows lack the muscle force capacity required for leaf-cutting, and their head capsule is so compliant that large muscle forces would be likely to cause damaging deformations. On the basis of these results, we speculate that continued biomechanical development post eclosion may be a key factor underlying age polyethism, wherever foraging is associated with substantial mechanical demands.
Topics: Animals; Biomechanical Phenomena; Ants; Muscles; Bite Force; Gastropoda
PubMed: 37312549
DOI: 10.1098/rspb.2023.0355 -
Journal of Comparative Physiology. A,... Jul 2023Efficient spatial orientation in the natural environment is crucial for the survival of most animal species. Cataglyphis desert ants possess excellent navigational... (Review)
Review
Efficient spatial orientation in the natural environment is crucial for the survival of most animal species. Cataglyphis desert ants possess excellent navigational skills. After far-ranging foraging excursions, the ants return to their inconspicuous nest entrance using celestial and panoramic cues. This review focuses on the question about how naïve ants acquire the necessary spatial information and adjust their visual compass systems. Naïve ants perform structured learning walks during their transition from the dark nest interior to foraging under bright sunlight. During initial learning walks, the ants perform rotational movements with nest-directed views using the earth's magnetic field as an earthbound compass reference. Experimental manipulations demonstrate that specific sky compass cues trigger structural neuronal plasticity in visual circuits to integration centers in the central complex and mushroom bodies. During learning walks, rotation of the sky-polarization pattern is required for an increase in volume and synaptic complexes in both integration centers. In contrast, passive light exposure triggers light-spectrum (especially UV light) dependent changes in synaptic complexes upstream of the central complex. We discuss a multisensory circuit model in the ant brain for pathways mediating structural neuroplasticity at different levels following passive light exposure and multisensory experience during the performance of learning walks.
Topics: Animals; Ants; Learning; Brain; Cues; Walking; Homing Behavior; Desert Climate
PubMed: 36494572
DOI: 10.1007/s00359-022-01600-y -
Proceedings. Biological Sciences Feb 2019Colour processing at early stages of visual pathways is a topic of intensive study both in vertebrate and invertebrate species. However, it is still unclear how colour...
Colour processing at early stages of visual pathways is a topic of intensive study both in vertebrate and invertebrate species. However, it is still unclear how colour learning and memory formation affects an insect brain in the peripheral processing stages and high-order integration centres, and whether associative colour experiences are reflected in plasticity of underlying neuronal circuits. To address this issue, we used Camponotus blandus ants as their proven colour learning and memory capabilities, precisely controllable age and experience, and already known central visual pathways offer unique access to analyse plasticity in neuronal circuits for colour vision in a miniature brain. The potential involvement of distinct neuropils-optic lobes (OLs), mushroom body (MB) input (collar) and output (vertical lobe), anterior optic tubercle (AOTU) and central complex (CX)-in associative colour experiences was assessed by quantification of volumetric and synaptic changes (MB collar) directly after colour conditioning and, 3 days later, after the establishment of long-term memory (LTM). To account for potential effects of non-associative light exposure, we compared neuronal changes in the brain of colour-naive foragers with those of foragers that had been exposed to light in a non-associative way. The results clearly show that the OLs, AOTU, and CX respond with plastic changes after colour learning and LTM formation. This suggests a complex neuronal network for colour learning and memory formation involving multiple brain levels. Such a colour-processing network probably represents an efficient design promoting fast and accurate behavioural decisions during orientation and navigation.
Topics: Animals; Ants; Color; Learning; Neuronal Plasticity; Neuropil; Random Allocation; Visual Pathways
PubMed: 30963920
DOI: 10.1098/rspb.2018.2813