I am interested in the complex interactions that govern collective behaviour, ecology, and self-organisation within social insects. My research centres upon the intersection between fundamental investigations of colony functioning, and applied work in ecology and epidemiology. I utilise ants, honey bees, bumble bees, and termites as models to assess network dynamics, with a focus on the role of interindividual heterogeneity.
Currently, I am involved in projects pertaining to honey bee epidemiology and genetics, the dynamics of parasite-pathogen interactions within insect colonies, the effect of mosquito control compounds upon bumble bees, and the detection and behavioural classification of invasive hornets using artificial intelligence.
The central aim of my research is to leverage an understanding of the rules underpinning complex systems; both to solve real-world challenges, and enhance mechanistic knowledge at a variety of scales. I value social insect models, as they provide tractable and fascinating tools with which to investigate applied and fundamental questions in biology.
Rojas-Nossa SV, O'Shea-Wheller TA, Poidatz J, Mato S, Osborne J, Garrido J (2023). Predator and pollinator? an invasive hornet alters the pollination dynamics of a native plant. Basic and Applied Ecology, 71, 119-128.
O'Shea-Wheller TA, Curtis RJ, Kennedy PJ, Groom EKJ, Poidatz J, Raffle DS, Rojas-Nossa SV, Bartolomé C, Dasilva-Martins D, Maside X, et al (2023). Quantifying the impact of an invasive Hornet on Bombus terrestris Colonies. Commun Biol, 6(1).
Abstract: Quantifying the impact of an invasive Hornet on Bombus terrestris Colonies.
The invasive hornet Vespa velutina nigrithorax is considered a proliferating threat to pollinators in Europe and Asia. While the impact of this species on managed honey bees is well-documented, effects upon other pollinator populations remain poorly understood. Nonetheless, dietary analyses indicate that the hornets consume a diversity of prey, fuelling concerns for at-risk taxa. Here, we quantify the impact of V. velutina upon standardised commercially-reared colonies of the European bumblebee, Bombus terrestris terrestris. Using a landscape-scale experimental design, we deploy colonies across a gradient of local V. velutina densities, utilising automated tracking to non-invasively observe bee and hornet behaviour, and quantify subsequent effects upon colony outcomes. Our results demonstrate that hornets frequently hunt at B. terrestris colonies, being preferentially attracted to those with high foraging traffic, and engaging in repeated-yet entirely unsuccessful-predation attempts at nest entrances. Notably however, we show that B. terrestris colony weights are negatively associated with local V. velutina densities, indicating potential indirect effects upon colony growth. Taken together, these findings provide the first empirical insight into impacts on bumblebees at the colony level, and inform future mitigation efforts for wild and managed pollinators.
O'Shea-Wheller TA, Rinkevich FD, Danka RG, Simone-Finstrom M, Tokarz PG, Healy KB (2022). A derived honey bee stock confers resistance to Varroa destructor and associated viral transmission. Sci Rep, 12(1).
Abstract: A derived honey bee stock confers resistance to Varroa destructor and associated viral transmission.
The ectoparasite Varroa destructor is the greatest threat to managed honey bee (Apis mellifera) colonies globally. Despite significant efforts, novel treatments to control the mite and its vectored pathogens have shown limited efficacy, as the host remains naïve. A prospective solution lies in the development of Varroa-resistant honey bee stocks, but a paucity of rigorous selection data restricts widespread adoption. Here, we characterise the parasite and viral dynamics of a Varroa-resistant honey bee stock, designated 'Pol-line', using a large-scale longitudinal study. Results demonstrate markedly reduced Varroa levels in this stock, diminished titres of three major viruses (DWV-A, DWV-B, and CBPV), and a two-fold increase in survival. Levels of a fourth virus that is not associated with Varroa-BQCV-do not differ between stocks, supporting a disruption of the transmission pathway. Further, we show that when decoupled from the influence of Varroa levels, viral titres do not constitute strong independent predictors of colony mortality risk. These findings highlight the need for a reassessment of Varroa etiology, and suggest that derived stocks represent a tractable solution to the Varroa pandemic.
McNamara TD, O’Shea-Wheller TA, DeLisi N, Dugas E, Caillouet KA, Vaeth R, Wallette D, Healy K (2020). An Efficient Alternative to the CDC Gravid Trap for Southern House Mosquito (Diptera: Culicidae) Surveillance. Journal of Medical Entomology, 58(3), 1322-1330.
Abstract: An Efficient Alternative to the CDC Gravid Trap for Southern House Mosquito (Diptera: Culicidae) Surveillance
Abstract . West Nile virus (WNV) is the most prevalent arbovirus found throughout the United States. Surveillance of surface breeding Culex vectors involved in WNV transmission is primarily conducted using CDC Gravid traps. However, anecdotal claims from mosquito abatement districts in Louisiana assert that other trap types may be more suited to WNV surveillance. To test the validity of these assertions, we conducted a series of trapping trials and WNV surveillance over 3 yr to compare the efficacy of multiple trap types. First, we compared the CDC Gravid trap, CO2-baited New Standard Miniature Blacklight traps, and CO2-baited CDC light traps with either an incandescent light, a red light, or no light. We found that the CDC Gravid trap and CO2-baited no-light CDC Light trap collected the most mosquitoes. Second, we conducted additional, long-term trapping and WNV surveillance to compare these two trap types. We found that CO2-baited no-light CDC traps collected more of the local WNV vector, Culex quinquefasciatus (Say, Diptera, Culicidae), and detected WNV with greater sensitivity. Finally, we conducted trapping to compare the physiological states of Cx. quinquefasciatus and diversity of collected mosquitoes. CO2-baited no-light CDC light traps collected more unfed Cx. quinquefasciatus while Gravid traps collected more blooded Cx. quinquefasciatus; both traps collected the same number of gravid Cx. quinquefasciatus. Additionally, we found that CO2-baited no-light CDC light traps collected a larger diversity of mosquito species than Gravid traps.
O’Shea-Wheller TA, Hunt ER, Sasaki T (2020). Functional Heterogeneity in Superorganisms: Emerging Trends and Concepts. Annals of the Entomological Society of America, 114(5), 562-574.
Abstract: Functional Heterogeneity in Superorganisms: Emerging Trends and Concepts
Abstract . Social insects are biological benchmarks of self-organization and decentralized control. Their integrated yet accessible nature makes them ideal models for the investigation of complex social network interactions, and the mechanisms that shape emergent group capabilities. Increasingly, interindividual heterogeneity, and the functional role that it may play, is seen as an important facet of colonies’ social architecture. Insect superorganisms present powerful model systems for the elucidation of conserved trends in biology, through the strong and consistent analogies that they display with multicellular organisms. As such, research relating to the benefits and constraints of heterogeneity in behavior, morphology, phenotypic plasticity, and colony genotype provides insight into the underpinnings of emergent collective phenomena, with rich potential for future exploration. Here, we review recent advances and trends in the understanding of functional heterogeneity within social insects. We highlight the scope for fundamental advances in biological knowledge, and the opportunity for emerging concepts to be verified and expanded upon, with the aid of bioinspired engineering in swarm robotics, and computational task allocation.
O'Shea-Wheller TA (2019). Honeybees show a context-dependent rightward bias. Biology Letters, 15(2), 20180877-20180877.
Abstract: Honeybees show a context-dependent rightward bias
. Lateralized behaviour in social insects is of biological significance, as certain lateral biases appear to have emerged in tandem with eusociality, and thus can provide insights into its functioning. Here, I investigate behavioural asymmetry in an ecologically important social insect, the honeybee . Apis mellifera. . Experiments show that foraging bees exhibit a strong rightward turning bias, accompanied by reduced decision latency when entering open cavities, yet demonstrate no directional preference in sequential choice-mazes. A rightward exploration preference within unknown cavities is consistent with current information relating to the physiology of this species, with workers being better equipped for sensory investigation and threat response using their right antenna and eye. Furthermore, when applied to collective nest-choice scenarios, a similar bias would promote the uniform assessment of nest cavities, and consistency in quorum attainment. Conversely, such laterality appears to provide no immediate advantage in enclosed decision-maze systems, where thigmotaxis instead predominates. As such, my results show that directional biases in . A. mellifera . are extent, yet context-dependent, thus providing a simple and optimized response to varied social challenges. .
Kennedy P, Baron G, Qiu B, Freitak D, Helanterä H, Hunt ER, Manfredini F, O'Shea-Wheller T, Patalano S, Pull CD, et al (2017). Deconstructing Superorganisms and Societies to Address Big Questions in Biology. Trends Ecol Evol, 32(11), 861-872.
Abstract: Deconstructing Superorganisms and Societies to Address Big Questions in Biology.
Social insect societies are long-standing models for understanding social behaviour and evolution. Unlike other advanced biological societies (such as the multicellular body), the component parts of social insect societies can be easily deconstructed and manipulated. Recent methodological and theoretical innovations have exploited this trait to address an expanded range of biological questions. We illustrate the broadening range of biological insight coming from social insect biology with four examples. These new frontiers promote open-minded, interdisciplinary exploration of one of the richest and most complex of biological phenomena: sociality.
O'Shea-Wheller TA, Masuda N, Sendova-Franks AB, Franks NR (2017). Variability in individual assessment behaviour and its implications for collective decision-making. Proceedings of the Royal Society B: Biological Sciences, 284(1848), 20162237-20162237.
Abstract: Variability in individual assessment behaviour and its implications for collective decision-making
. Self-organized systems of collective behaviour have been demonstrated in a number of group-living organisms. There is, however, less research relating to how variation in individual assessments may facilitate group decision-making. Here, we investigate this using the decentralized system of collective nest choice behaviour employed by the ant . Temnothorax albipennis, . combining experimental results with computational modelling. In experiments, isolated workers of this species were allowed to investigate new nest sites of differing quality, and it was found that for any given nest quality, there was wide variation among individuals in the durations that they spent within each nest site. Additionally, individual workers were consistent in spending more time in nest sites of higher quality, and less time in those of lower quality. Hence, the time spent in a new nest site must have included an assessment of nest quality. As nest site visit durations (henceforth termed assessment durations) are linked to recruitment, it is possible that the variability we observed may influence the collective decision-making process of colonies. Thus, we explored this further using a computational model of nest site selection, and found that heterogeneous nest assessments conferred a number of potential benefits. Furthermore, our experiments showed that nest quality assessments were flexible, being influenced by experience of prior options. Our findings help to elucidate the potential mechanisms underlying group behaviour, and highlight the importance of heterogeneity among individuals, rather than precise calibration, in shaping collective decision-making. .
O'Shea-Wheller TA, Wilson-Aggarwal DK, Edgley DE, Sendova-Franks AB, Franks NR (2016). A social mechanism facilitates ant colony emigrations over different distances. Journal of Experimental Biology
Abstract: A social mechanism facilitates ant colony emigrations over different distances
Behavioural responses enable animals to react rapidly to fluctuating environments. In eusocial organisms, such changes are often enacted at the group level, but may be organised in a decentralised fashion by the actions of individuals. However, the contributions of different group members are rarely homogenous, and there is evidence to suggest that certain ‘keystone’ individuals are important in shaping collective responses. Accordingly, investigations of the dynamics and structuring of behavioural changes at both the group and individual level, are crucial for evaluating the relative influence of different individuals. Here, we examine the composition of tandem running behaviour during colony emigrations in the ant species Temnothorax albipennis. Tandem running is modulated in response to emigration distance, with more runs being conducted when a more distant nest site must be reached. We show that certain individuals are highly active in the tandem running process, attempting significantly more work in the task. Contrary to expectations, however, such individuals are in fact no more successful at conducting tandem runs than their less active nest mates. Instead, it seems that when more tandem runs are required, colonies rely on greater recruitment of workers into the process. The implications of our study are that in some cases, even when apparently ‘key’ individuals exist within a group, their relative contribution to task performance may be far from decisive.
O’Shea-Wheller TA, Sendova-Franks AB, Franks NR (2016). Migration control: a distance compensation strategy in ants. The Science of Nature, 103(7-8).
Masuda N, O'shea-Wheller TA, Doran C, Franks NR (2015). Computational model of collective nest selection by ants with heterogeneous acceptance thresholds. R Soc Open Sci, 2(6).
Abstract: Computational model of collective nest selection by ants with heterogeneous acceptance thresholds.
Collective decision-making is a characteristic of societies ranging from ants to humans. The ant Temnothorax albipennis is known to use quorum sensing to collectively decide on a new home; emigration to a new nest site occurs when the number of ants favouring the new site becomes quorate. There are several possible mechanisms by which ant colonies can select the best nest site among alternatives based on a quorum mechanism. In this study, we use computational models to examine the implications of heterogeneous acceptance thresholds across individual ants in collective nest choice behaviour. We take a minimalist approach to develop a differential equation model and a corresponding non-spatial agent-based model. We show, consistent with existing empirical evidence, that heterogeneity in acceptance thresholds is a viable mechanism for efficient nest choice behaviour. In particular, we show that the proposed models show speed-accuracy trade-offs and speed-cohesion trade-offs when we vary the number of scouts or the quorum threshold.
O'Shea-Wheller TA, Sendova-Franks AB, Franks NR (2015). Differentiated Anti-Predation Responses in a Superorganism. PLoS One, 10(11).
Abstract: Differentiated Anti-Predation Responses in a Superorganism.
Insect societies are complex systems, displaying emergent properties much greater than the sum of their individual parts. As such, the concept of these societies as single 'superorganisms' is widely applied to describe their organisation and biology. Here, we test the applicability of this concept to the response of social insect colonies to predation during a vulnerable period of their life history. We used the model system of house-hunting behaviour in the ant Temnothorax albipennis. We show that removing individuals from directly within the nest causes an evacuation response, while removing ants at the periphery of scouting activity causes the colony to withdraw back into the nest. This suggests that colonies react differentially, but in a coordinated fashion, to these differing types of predation. Our findings lend support to the superorganism concept, as the whole society reacts much like a single organism would in response to attacks on different parts of its body. The implication of this is that a collective reaction to the location of worker loss within insect colonies is key to avoiding further harm, much in the same way that the nervous systems of individuals facilitate the avoidance of localised damage.
Hunt ER, O'Shea-Wheller T, Albery GF, Bridger TH, Gumn M, Franks NR (2014). Ants show a leftward turning bias when exploring unknown nest sites. Biol Lett, 10(12).
Abstract: Ants show a leftward turning bias when exploring unknown nest sites.
Behavioural lateralization in invertebrates is an important field of study because it may provide insights into the early origins of lateralization seen in a diversity of organisms. Here, we present evidence for a leftward turning bias in Temnothorax albipennis ants exploring nest cavities and in branching mazes, where the bias is initially obscured by thigmotaxis (wall-following) behaviour. Forward travel with a consistent turning bias in either direction is an effective nest exploration method, and a simple decision-making heuristic to employ when faced with multiple directional choices. Replication of the same bias at the colony level would also reduce individual predation risk through aggregation effects, and may lead to a faster attainment of a quorum threshold for nest migration. We suggest the turning bias may be the result of an evolutionary interplay between vision, exploration and migration factors, promoted by the ants' eusociality.
Laycock I, Cotterell KC, O'Shea-Wheller TA, Cresswell JE (2014). Effects of the neonicotinoid pesticide thiamethoxam at field-realistic levels on microcolonies of Bombus terrestris worker bumble bees. Ecotoxicology and Environmental Safety, 100(1), 153-158.
Abstract: Effects of the neonicotinoid pesticide thiamethoxam at field-realistic levels on microcolonies of Bombus terrestris worker bumble bees
Laycock I, Cotterell KC, O'Shea-Wheller TA, Cresswell JE (2014). Effects of the neonicotinoid pesticide thiamethoxam at field-realistic levels on microcolonies of Bombus terrestris worker bumble bees. Ecotoxicol Environ Saf, 100, 153-158.
Abstract: Effects of the neonicotinoid pesticide thiamethoxam at field-realistic levels on microcolonies of Bombus terrestris worker bumble bees.
Neonicotinoid pesticides are currently implicated in the decline of wild bee populations. Bumble bees, Bombus spp. are important wild pollinators that are detrimentally affected by ingestion of neonicotinoid residues. To date, imidacloprid has been the major focus of study into the effects of neonicotinoids on bumble bee health, but wild populations are increasingly exposed to alternative neonicotinoids such as thiamethoxam. To investigate whether environmentally realistic levels of thiamethoxam affect bumble bee performance over a realistic exposure period, we exposed queenless microcolonies of Bombus terrestris L. workers to a wide range of dosages up to 98 μgkg(-1) in dietary syrup for 17 days. Results showed that bumble bee workers survived fewer days when presented with syrup dosed at 98 μg thiamethoxamkg(-1), while production of brood (eggs and larvae) and consumption of syrup and pollen in microcolonies were significantly reduced by thiamethoxam only at the two highest concentrations (39, 98 μgkg(-1)). In contrast, we found no detectable effect of thiamethoxam at levels typically found in the nectars of treated crops (between 1 and 11 μgkg(-1)). By comparison with published data, we demonstrate that during an exposure to field-realistic concentrations lasting approximately two weeks, brood production in worker bumble bees is more sensitive to imidacloprid than thiamethoxam. We speculate that differential sensitivity arises because imidacloprid produces a stronger repression of feeding in bumble bees than thiamethoxam, which imposes a greater nutrient limitation on production of brood.