Effects of coumaphos on locomotor activities of different honeybee (Apis mellifera L.) subspecies and ecotypes

The effects of acute sublethal doses of coumaphos, an acaricide used against Varroa destructor infestation in beekeeping, on the locomotor activities of four native honeybee subspecies of Türkiye including two ecotypes (Carniolan honeybee -A. m. carnica, Syrian honeybee -A. m. syriaca, Caucasian honeybee- A. m. caucasica, and Muğla and Yığılca ecotypes of Anatolian honeybee A. m. anatoliaca) were investigated using an individual locomotor activity monitoring system. Analysis of locomotor activity data in the first 12-h, last 12-h, and 24-h time periods showed that bees from caucasica and carnica subspecies were not affected by coumaphos at all three acute doses (1, 2, and 5 μg coumaphos in 10 μl sucrose syrup for each bee). In contrast, bees from A. m. syriaca subspecies showed significantly elevated locomotor activity levels at 2 and 5 μg coumaphos doses within the first 12 h. Bees from both Muğla and Yığılca ecotypes of anatoliaca subspecies also showed elevated locomotor activity levels at 5 μg coumaphos dose but the magnitude of increase was lower in these ecotypes compared to that seen in syriaca subspecies in the first 12-h period. In general, increasing doses of coumaphos resulted in increased locomotor activity (locomotor activity), with differences in sensitivity across honeybee populations. Possible mechanisms underlying this variance and suggestions for further studies are discussed

Influence of environmental experience on aversive conditioning in honey bees (Apis mellifera L.)

International audiencePrevious experience in a natural environment with a stimulus has lasting influences on honey bee behavior, as demonstrated in laboratory studies of appetitive conditioning. However, it is unknown whether the same holds true for studies of aversive conditioning. Aversive conditioning is important for insects such as honey bees to survive environmental risks. Previous experience in natural settings may lead to maladaptive behavioral patterns in bees exposed to new risks. This study presents the first examination of the effect of a visual stimulus presented in a naturalistic setting on aversive conditioning, using the shuttle box choice chamber paradigm. The present study examines both the effect of the visual stimuli, as well as differences present between the Apis mellifera subspecies of mellifera and ligustica. Results support the presence of behavioral biases based on the visual stimulus presented prior to the experimental sessions

Towards Automatic Honey Bee Flower-Patch Assays with Paint Marking Re-Identification

In this paper, we show that paint markings are a feasible approach to automatize the analysis of behavioral assays involving honey bees in the field where marking has to be as lightweight as possible. We contribute a novel dataset for bees re-identification with paint-markings with 4392 images and 27 identities. Contrastive learning with a ResNet backbone and triplet loss led to identity representation features with almost perfect recognition in closed setting where identities are known in advance. Diverse experiments evaluate the capability to generalize to separate IDs, and show the impact of using different body parts for identification, such as using the unmarked abdomen only. In addition, we show the potential to fully automate the visit detection and provide preliminary results of compute time for future real-time deployment in the field on an edge device.Comment: Paper 17, workshop "CV4Animals: Computer Vision for Animal Behavior Tracking and Modeling", in conjunction with Computer Vision and Pattern Recognition (CVPR 2023), June 18, 2023, Vancouver, Canad

Dopamine and Octopamine Influence Avoidance Learning of Honey Bees in a Place Preference Assay

Biogenic amines are widely characterized in pathways evaluating reward and punishment, resulting in appropriate aversive or appetitive responses of vertebrates and invertebrates. We utilized the honey bee model and a newly developed spatial avoidance conditioning assay to probe effects of biogenic amines octopamine (OA) and dopamine (DA) on avoidance learning. In this new protocol non-harnessed bees associate a spatial color cue with mild electric shock punishment. After a number of experiences with color and shock the bees no longer enter the compartment associated with punishment. Intrinsic aspects of avoidance conditioning are associated with natural behavior of bees such as punishment (lack of food, explosive pollination mechanisms, danger of predation, heat, etc.) and their association to floral traits or other spatial cues during foraging. The results show that DA reduces the punishment received whereas octopamine OA increases the punishment received. These effects are dose-dependent and specific to the acquisition phase of training. The effects during acquisition are specific as shown in experiments using the antagonists Pimozide and Mianserin for DA and OA receptors, respectively. This study demonstrates the integrative role of biogenic amines in aversive learning in the honey bee as modeled in a novel non-appetitive avoidance learning assay

Forecasting the Influence of Climate Change on Agroecosystem Services: Potential Impacts on Honey Yields in a Small-Island Developing State

Global change poses numerous challenges to developing nations and small-island developing states (SIDSs). Among these are the effects of climate change on honeybees’ provisioning services including honey production. Here we ask two questions. First, what is the relationship between honey yield and climate in a tropical environment? Second, how does yield vary spatially under current climate and future scenarios of climate change? Focusing on the island of Puerto Rico, we developed an ensemble of bioclimatic models that were used in a geographical information system to identify suitable areas for honey production under current and future scenarios of climate change. A comparison between contemporary (1998–2005) and historical (1910–1974) honey yield data revealed a reduction in average yield, including variability, over time, with current yields averaging 5.3 L/colony. Three bioclimatic variables were retained by at least three models: temperature seasonality and mean temperature of the wettest quarter were negatively correlated with honey yields whereas precipitation of the wettest month was positively correlated. The four models varied in terms of their predictions but showed that both honey yields and areas suitable for honey production will decrease under scenarios of climate change. These results illustrate the possible impacts of climate change on honey and ultimately honeybees

A soft selective sweep during rapid evolution of gentle behaviour in an Africanized honeybee

Africanized honey bees (AHB) are notoriously aggressive, but in Puerto Rico they have a ‘gentle’ phenotype. Here, Avalos et al. show that there has been a soft selective sweep at several loci in the Puerto Rican AHB population and suggest a role in the rapid evolution of gentle behaviour

Varroa destructor parasitism and genetic variability at honey bee (Apis mellifera) drone congregation areas and their associations with environmental variables in Argentina

Varroa destructor is a serious ectoparasite of the western honey bee, Apis mellifera, which negatively impacts on colonies health and survival worldwide. Drone-mediated movement and the presence of the mite in Drone Congregation Areas (DCA) may play a relevant role in Varroa dispersal. The objectives of this study were to characterize mite infestation levels and genetic diversity in DCAs and surrounding apiaries and to explore putative environmental variables associated to Varroa infestation in two eco-climatic regions of Argentina (temperate, and subtropical). Phoretic mite proportions in DCAs and apiaries were estimated during spring. Landscape, topographic, and climate variables were described using satellite image classifications and data from public databases. The genetic composition of drones at the DCAs and workers from the surrounding apiaries was assessed using mitochondrial markers. In total, eleven DCAs were identified in both regions during 2017 and 2018. The mean proportion of Varroa was ca. 3 in 1,000 (0.0028 ± 0.0046) at the apiaries, and ca. 2 in 100 (0.0168 ± 0.0227) at the DCAs. No statistical differences were observed between apiaries and DCAs or between ecoregions, but the proportion of infested males at the DCAs was positively correlated to the distance to the apiary and a trend was observed toward higher mite loads in DCAs. Landscape and topography were not determinant for Varroa infestation at the DCAs but relative humidity and precipitation in the previous week of sampling, positively influenced infestation. More haplotypic diversity was detected in the DCAs compared to the surrounding apiaries, particularly in the subtropical region. While in this region high prevalence of Africanized (A1, A4) mitochondrial lineages was detected, European lineages (C1, C2j) were mostly found in apiaries and DCA in the temperate region. Our results provide valuable information on the dynamics of Varroa parasitism in apiaries and DCAs, and highlight the role of drones in mite dispersion and genetic variability of new colonies. The study of DCAs emerges as a tool for investigating not only honey bee reproduction and conservation, but also the impact of the environment on bee epidemiology.Instituto de GenéticaFil: Galindo Cardona, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scannapieco, Alejandra Carla. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; Argentina.Fil: Russo, Romina María. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; ArgentinaFil: Escalante, Karen. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales; ArgentinaFil: Geria, Martín. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales; ArgentinaFil: Lepori, Nicolás. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales; ArgentinaFil: Ayup, María Marta. Universidad Nacional de Tucumán. Instituto de Ecología Regional; Argentina.Fil: Muntaabski, Irina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; Argentina.Fil: Liendo, María Clara. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; Argentina.Fil: Landi, Lucas. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Giray, Tugrul. Universidad de Puerto Rico. Departamento de Biología; Puerto RicoFil: Monmany-Garzia, A. Carolina. Universidad Nacional de Tucumán. Instituto de Ecología Regional; ArgentinaFil: Galindo Cardona, Alberto. Fundación Miguel Lillo; Argentina.Fil: Galindo Cardona, Alberto. Universidad Nacional de Tucumán. Instituto de Ecología Regional; ArgentinaFil: Scannapieco, Alejandra Carla. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ayup, María Marta. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales; ArgentinaFil: Muntaabski, Irina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Liendo, María Clara. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Appetitive reversal learning differences of two honey bee subspecies with different foraging behaviors

We aimed to examine mechanistically the observed foraging differences across two honey bee, Apis mellifera, subspecies using the proboscis extension response assay. Specifically, we compared differences in appetitive reversal learning ability between honey bee subspecies: Apis mellifera caucasica (Pollman), and Apis mellifera syriaca (Skorikov) in a “common garden” apiary. It was hypothesized that specific learning differences could explain previously observed foraging behavior differences of these subspecies: A.m. caucasica switches between different flower color morphs in response to reward variability, and A.m. syriaca does not switch. We suggest that flower constancy allows reduced exposure by minimizing search and handling time, whereas plasticity is important when maximizing harvest in preparation for long winter is at a premium. In the initial or Acquisition phase of the test we examined specifically discrimination learning, where bees were trained to respond to a paired conditioned stimulus with an unconditioned stimulus and not to respond to a second conditioned stimulus that is not followed by an unconditioned stimulus. We found no significant differences among the subspecies in the Acquisition phase in appetitive learning. During the second, Reversal phase of the experiment, where flexibility in association was tested, the paired and unpaired conditioned stimuli were reversed. During the Reversal phase A.m. syriaca showed a reduced ability to learn the reverse association in the appetitive learning task. This observation is consistent with the hypothesis that A.m. syriaca foragers cannot change the foraging choice because of lack of flexibility in appetitive associations under changing contingencies. Interestingly, both subspecies continued responding to the previously rewarded conditioned stimulus in the reversal phase. We discuss potential ecological correlates and molecular underpinnings of these differences in learning across the two subspecies. In addition, in a supplemental experiment we demonstrated that these differences in appetitive reversal learning do not occur in other learning contexts.National Science Foundation (NSF)Publisher's Versio

Proboscis conditioning experiments with honeybees, Apis mellifera caucasica, with butyric acid and DEET mixture as conditioned and unconditioned stimuli

Three experiments are described investigating whether olfactory repellents DEET and butyric acid can support the classical conditioning of proboscis extension in the honeybee, Apis mellifera caucasica (Hymenoptera: Apidae). In the first experiment DEET and butyric acid readily led to standard acquisition and extinction effects, which are comparable to the use of cinnamon as a conditioned stimulus. These results demonstrate that the odor of DEET or butyric acid is not intrinsically repellent to honey bees. In a second experiment, with DEET and butyric acid mixed with sucrose as an unconditioned stimulus, proboscis conditioning was not established. After several trials, few animals responded to the unconditioned stimulus. These results demonstrate that these chemicals are gustatory repellents when in direct contact. In the last experiment a conditioned suppression paradigm was used. Exposing animals to butyric acid or DEET when the proboscis was extended by direct sucrose stimulation or by learning revealed that retraction of the proboscis was similar to another novel odor, lavender, and in all cases greatest when the animal was not permitted to feed. These results again demonstrate that DEET or butyric acid are not olfactory repellents, and in addition, conditioned suppression is influenced by feeding state of the bee.Peer reviewedPsychologyZoolog

A communal catalogue reveals Earth’s multiscale microbial diversity

Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity