So near and yet so far: Harmonic radar reveals reduced homing ability of nosema infected honeybees

Pathogens may gain a fitness advantage through manipulation of the behaviour of their hosts. Likewise, host behavioural changes can be a defence mechanism, counteracting the impact of pathogens on host fitness. We apply harmonic radar technology to characterize the impact of an emerging pathogen - Nosema ceranae (Microsporidia) - on honeybee (Apis mellifera) flight and orientation performance in the field. Honeybees are the most important commercial pollinators. Emerging diseases have been proposed to play a prominent role in colony decline, partly through sub-lethal behavioural manipulation of their hosts. We found that homing success was significantly reduced in diseased (65.8%) versus healthy foragers (92.5%). Although lost bees had significantly reduced continuous flight times and prolonged resting times, other flight characteristics and navigational abilities showed no significant difference between infected and non-infected bees. Our results suggest that infected bees express normal flight characteristics but are constrained in their homing ability, potentially compromising the colony by reducing its resource inputs, but also counteracting the intra-colony spread of infection. We provide the first high-resolution analysis of sub-lethal effects of an emerging disease on insect flight behaviour. The potential causes and the implications for both host and parasite are discussed

So near and yet so far: Harmonic radar reveals reduced homing ability of nosema infected honeybees

Pathogens may gain a fitness advantage through manipulation of the behaviour of their hosts. Likewise, host behavioural changes can be a defence mechanism, counteracting the impact of pathogens on host fitness. We apply harmonic radar technology to characterize the impact of an emerging pathogen - Nosema ceranae (Microsporidia) - on honeybee (Apis mellifera) flight and orientation performance in the field. Honeybees are the most important commercial pollinators. Emerging diseases have been proposed to play a prominent role in colony decline, partly through sub-lethal behavioural manipulation of their hosts. We found that homing success was significantly reduced in diseased (65.8%) versus healthy foragers (92.5%). Although lost bees had significantly reduced continuous flight times and prolonged resting times, other flight characteristics and navigational abilities showed no significant difference between infected and non-infected bees. Our results suggest that infected bees express normal flight characteristics but are constrained in their homing ability, potentially compromising the colony by reducing its resource inputs, but also counteracting the intra-colony spread of infection. We provide the first high-resolution analysis of sub-lethal effects of an emerging disease on insect flight behaviour. The potential causes and the implications for both host and parasite are discussed

Effects of Pesticide Residue Accumulation on Honey Bee (\u3ci\u3eApis mellifera\u3c/i\u3e L.) Development & Implications for Hive Management

Honey bee (Apis mellifera L.) colonies face annual declines of 40% in the United States. Pesticides play a role in these losses. Pesticide residues picked up from the environment as well as beekeeper-applied compounds may accumulate within the hive. The effects of pesticide accumulation in comb on bee health mitigation of accumulation have not been well-studied. To examine pesticide exposure on health and development, chlorothalonil and the amitraz metabolite N-(2,4-dimethylphenyl) formamidine (DMPF), two pesticides found in hive products, were applied to brood comb. Queen bees were caged onto treated and control comb and egg laying and development were assessed. Adult bee health measures were also examined to determine the indirect effects on worker bee tasks. Results from this study indicates that bee larvae reared in comb with DMPF developed significantly smaller acini within the hypopharyngeal glands. Exposure to newer chemistries, does not typically result in rapid high losses of worker bees but instead colonies exhibit slow chronic losses over time, indicating impacts may be due to persistent residual effects within the colony. Here, we assessed the use of dead bee traps for monitoring pesticide incidents to identify exposure at the onset. To assess efficacy of traps, worker bees were treated with imidacloprid or freeze-killed bees (positive control) and put back into hives to determine trap recapture rate. Dead bee traps recaptured 27.7% of bees from the positive control group though sub-lethal doses of imidacloprid bees were recovered at significantly lower rates. Traps from three separate apiaries were also monitored weekly to assess seasonal patterns of losses and found distinct differences for each apiary between months in observed abnormal mortality. Results from this study may determine how factors like pesticides can be monitored and may lead to management recommendations. This thesis concludes with a detailed instructional guide for beekeepers to properly build and use them as well as provides other resources to encourage beekeepers to monitor for other hive stressors. Advisor: Judy Wu-Smar

So near and yet so far: harmonic radar reveals reduced homing ability of Nosema infected honeybees.

© 2014 Wolf et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Citation: Wolf S, McMahon DP, Lim KS, Pull CD, Clark SJ, et al. (2014) So Near and Yet So Far: Harmonic Radar Reveals Reduced Homing Ability of Nosema Infected Honeybees. PLoS ONE 9(8): e103989. doi:10.1371/journal.pone.0103989Pathogens may gain a fitness advantage through manipulation of the behaviour of their hosts. Likewise, host behavioural changes can be a defence mechanism, counteracting the impact of pathogens on host fitness. We apply harmonic radar technology to characterize the impact of an emerging pathogen--Nosema ceranae (Microsporidia)--on honeybee (Apis mellifera) flight and orientation performance in the field. Honeybees are the most important commercial pollinators. Emerging diseases have been proposed to play a prominent role in colony decline, partly through sub-lethal behavioural manipulation of their hosts. We found that homing success was significantly reduced in diseased (65.8%) versus healthy foragers (92.5%). Although lost bees had significantly reduced continuous flight times and prolonged resting times, other flight characteristics and navigational abilities showed no significant difference between infected and non-infected bees. Our results suggest that infected bees express normal flight characteristics but are constrained in their homing ability, potentially compromising the colony by reducing its resource inputs, but also counteracting the intra-colony spread of infection. We provide the first high-resolution analysis of sub-lethal effects of an emerging disease on insect flight behaviour. The potential causes and the implications for both host and parasite are discussed.Biotechnology and Biological Sciences Research Council (BBSRC)Department for Environment Food & Rural Affairs (DEFRA)Natural Environment Research Council (NERC)The Scottish GovernmentWellcome Trus

Ant-proofing the apiary

During the warmer months the infiltration of ants into an apiary can provide the beekeeper with some serious problems. At a time when his thoughts should be on extraction and honey crop problems, the hive-owner is little interested in studying the habits of various attacking ants, and cannot afford to waste valuable time in devising methods of ant eradication

Spatio-Temporal Patterns act as Computational Mechanisms governing Emergent behavior in Robotic Swarms

open access articleOur goal is to control a robotic swarm without removing its swarm-like nature. In other words, we aim to intrinsically control a robotic swarm emergent behavior. Past attempts at governing robotic swarms or their selfcoordinating emergent behavior, has proven ineffective, largely due to the swarm’s inherent randomness (making it difficult to predict) and utter simplicity (they lack a leader, any kind of centralized control, long-range communication, global knowledge, complex internal models and only operate on a couple of basic, reactive rules). The main problem is that emergent phenomena itself is not fully understood, despite being at the forefront of current research. Research into 1D and 2D Cellular Automata has uncovered a hidden computational layer which bridges the micromacro gap (i.e., how individual behaviors at the micro-level influence the global behaviors on the macro-level). We hypothesize that there also lie embedded computational mechanisms at the heart of a robotic swarm’s emergent behavior. To test this theory, we proceeded to simulate robotic swarms (represented as both particles and dynamic networks) and then designed local rules to induce various types of intelligent, emergent behaviors (as well as designing genetic algorithms to evolve robotic swarms with emergent behaviors). Finally, we analysed these robotic swarms and successfully confirmed our hypothesis; analyzing their developments and interactions over time revealed various forms of embedded spatiotemporal patterns which store, propagate and parallel process information across the swarm according to some internal, collision-based logic (solving the mystery of how simple robots are able to self-coordinate and allow global behaviors to emerge across the swarm)

Spartan Daily, April 29, 1968

Volume 55, Issue 113https://scholarworks.sjsu.edu/spartandaily/5058/thumbnail.jp

Hygienic behaviour in honey bees

This thesis focuses on hygienic behaviour in honey bees. In beekeeping, brood diseases incur heavy economical and biological costs and are no longer effectively treated with chemicals. Previous research has shown how hygienic behaviour, a trait expressed by c. 10% of unselected colonies, can be effective in reducing the impact and presence of such diseases. Hygienic behaviour is experimentally measured using the freeze-killed brood (FKB) bioassay and can be increased by selective breeding, generating lines of hygienic colonies. Chapter 4 demonstrates that the relative rarity of hygienic behaviour in unselected colonies is not because it incurs a cost via the removal of healthy brood. Chapter 5 - 6 focus on the impact of external factors on hygienic behaviour. Specifically, we demonstrate that the presence of brood, amount of food, and strength of the colony affect hygienic levels (Chapter 5). Chapter 6 shows that hygienic behaviour does not correlate with agressiviness or agitated behaviour. When breeding honey bees, it is possible to exploit instrumental insemination to have complete control over the genetic composition of the resulting progeny. This technique is however laborious and requires particular equipment and training. In Chapter 7 we show that it is possible to obtain acceptable levels of hygienic behaviour without artificial insemination. Chapter 8 illustrates how we obtained the first breeing line of hygienic honey bees through a selective breeding program that saw its first milestone in autumn 2013 when we detected high levels of hygienic behaviour. The results obtained represent the foundation for future research projects. Chapter 9 presents a valid, minimal methodology to keep virgin queens. We tested a variety of methods and factors to determine the best, mos cost-effective way to maintain queens for the week prior their introduction into a queenless hive. The results obtained provide some insights on both basic and applied aspects of honey bee breeding for hygienic behaviour and represent the foundation of what will be an ongoing selection programme towards a disease-resistant honey bee