The genetic variability in 25 honey bee colonies from different regions of Bulgaria with diverse hygienic behaviour (super hygienic, hygienic and non-hygienic) has been studied. Alloenzyme analysis ...of two systems (MDH-1 and EST-3) corresponding to 2 loci was used in order to characterize the colony polymorphism. Totally 1,150 worker bees were included in this investigation. MDH-1 locus was found to be polymorphic in all of the studied colonies, having two alleles – MDH-165 and MDH-1100. The EST-3 locus was fixed in ten of the investigated colonies. Polymorphism with total presence of four alleles of this locus (EST-380, EST-388, EST-3100 and EST-3118) was found in the other studied colonies. The calculated polymorphism was between 50% and 100%. The observed and expected heterozygosities (Ho and He) ranged from 0.296 to 0.354 and from 0.280 to 0.332 in non-hygienic and super hygienic groups, respectively. The calculated mean observed and expected heterozygosities were 0.320 and 0.307, respectively. The calculated Fst and Nm levels demonstrated lower differentiation between super hygienic and hygienic colonies and higher differentiation between super hygienic and non-hygienic colonies. Dissimilarities between levels of polymorphism, heterozygosity, Fst, Nm and allele frequencies in the studied groups of colonies with different hygienic behaviour were found and discussed. The results of the present study provide new information concerning relations between hygienic behaviour and allozyme characteristics which could be used for future selection with honey bees in Bulgaria.
Healthcare-associated infections (HAIs) are considered to be one of the biggest health problems as they continue to be an important cause of morbidity and mortality worldwide. They cannot be ...completely prevented, but their incidence can be significantly limited. Preventive action is the most important measure in this case. Due to the frequent interaction between healthcare professionals and patients, the crucial importance of hand hygiene is therefore emphasised. Adherence to good disinfection and hand washing practices remains around 40%, which can be improved by using a variety of nudge tools to promote desired hygienic behaviour. We conducted an open observation of employees and visitors with participation. The aim of this study was to determine the actual status of hand disinfection in a selected healthcare facility amongst doctors, registered nurses, medical technicians, cleaners, and visitors or parents of children; then, we selected and introduced three nudge tools of desired hygiene behaviour and analysed their effectiveness; finally, we provided suggestions for the use of nudge tools of desired hygiene behaviour with the aim of influencing doctors, registered nurses, medical technicians, cleaners, and visitors or parents of children so that they disinfect their hands properly. The actual state of hand disinfection was determined on the basis of observation without introducing any changes; then, we separately introduced three nudge tools, posters with an inscription and picture, the scent of citrus, and flashing lights. The obtained results were analysed with the help of the SpeedyAudit Lite application, and the effectiveness of each nudge tool and the adequacy of hand disinfection by categories of people were compared. In general, posters with a picture and an inscription contributed the most to more consistent disinfection of employees’ hands, while the scent of citrus and flashing lights contributed slightly less.
Hygienic behaviour is a natural mechanism of colony-level disease resistance to brood pathogens and has been reported in honey bees and stingless bees. A novel brood disease was recently confirmed in ...the Australian stingless bees Tetragonula carbonaria Smith and Tetragonula hockingsi Cockerell and there is a paucity of data available on hygienic behaviour in these species. To address this, we investigated hygienic behaviour in eight colonies of T. carbonaria and four colonies of T. hockingsi, using brood freeze-kill and pin-kill assays. Hygienic behaviour was present in both species and was rapidly expressed in both assays. In T. carbonaria, the mean time (± SE) for removal of freeze-killed and pin-killed brood was 9.1 ± 1.9 hours and 8.2 ± 0.9 hours, respectively (n = 8; one trial per assay). In T. hockingsi, removal of freeze-killed and pin-killed brood was 14.1 ± 5.1 hours and 10.4 (no SE) hours, respectively. There was no significant difference (α = 0.05) in time taken to complete the hygienic behaviour phases (detection, uncapping, removal or cell dismantling) between assay type or assay order in both species. However, intercolony variation was observed in both species in the assays, suggesting that like honey bees, hygienic behaviour may have a genetic component. Tetragonula carbonaria and T. hockingsi displayed significantly faster detection, uncapping, removal and cell dismantling times than any of the stingless bees or most honey bees studied previously. This may, in part, explain why stingless bees appear to suffer from relatively few brood diseases.
Abstract
Backgrounds
Preventive behaviours are an essential way to slow down and eliminate the transmission of SARS-CoV-2. The aim of this study was to estimate adherence to preventive behaviors and ...to identify whether any subgroups were not adopting these behaviours and for whom greater engagement in these approaches was indicated.
Methods
In this cross-sectional study, we obtained data from a random sample of a panel representing men and women of adult age residing in Hungary (
N
= 5254). The survey included questions about the frequencies of preventive behaviours, perceived susceptibility and severity of COVID-19.
Results
We found four factors of preventive behaviours: using physical barriers (mask and gloves), avoidance of close contacts, personal hygiene, and preparation. We identified two broadly adherent groups (36.8 and 45.3%) and two non-adherent groups (13.1 and 4.8%). Being male and being aged between 18 and 29 years were the strongest predictors of non-adherence. Concern about the severity of COVID-19 was a predictor of adherence.
Conclusions
To ensure maximal adherence to preventive behaviours for COVID-19, additional strategies should focus on their adoption by men and young adults.
The hygienic behavior in honey bees is a complex polygenic trait that serves as a natural defense mechanism against bacterial and fungal brood diseases and
mites infesting brood cells. The aim of ...this study was to evaluate the effect of a dietary amino acids and vitamins supplement “BEEWELL AminoPlus” on hygienic behavior of
colonies combating microsporidial and viral infections. The experiment was performed during a one-year period on 40 colonies alloted to five groups: one supplemented and infected with
and four viruses (Deformed wing virus - DWV, Acute bee paralysis virus - ABPV, Chronic bee paralysis virus - CBPV and Sacbrood virus – SBV), three not supplemented, but infected with
and/ or viruses, and one negative control group. Beside the l isted pathogens, honey bee trypanosomatids were also monitored in all groups.
The supplement “BEEWELL AminoPlus” induced a significant and consistent increase of the hygienic behavior in spite of the negative effects of
and viral infections.
and viruses significantly and consistently decreased hygienic behavior, but also threatened the survival of bee colonies. The tested supplement showed anti-
effect, since the
infection level significantly and consistently declined only in the supplemented group. Among infected groups, only the supplemented one remained
-free throughout the study. In conclusion, diet supplementation enhances hygienic behavior of honey bee colonies and helps them fight the most common infections of honey bees.
Animals living in large colonies are especially vulnerable to infectious pathogens and may therefore have evolved additional defences. Eusocial insects supplement their physiological immune systems ...with ‘social immunity’, a set of adaptations that impedes the entrance, establishment, and spread of pathogens in the colony. We here find that honey bee workers (
Apis mellifera
) that had been experimentally immune-challenged with bacterial lipopolysaccharide (LPS) often exited the hive and subsequently died; some individuals were dragged out by other workers, while others appeared to leave voluntarily. In a second experiment, we found that healthy workers treated with surface chemicals from LPS-treated bees were evicted from the hive more often than controls, indicating that immune-challenged bees produce chemical cues or signals that elicit their eviction. Thirdly, we observed pairs of bees under lab conditions, and found that pairs spent more time apart when one member of the pair had received LPS, relative to controls. Our findings suggest that immune-challenged bees altruistically banish themselves, and that workers evict sick individuals which they identify using olfactory cues, putatively because of (kin) selection to limit the spread of pathogens within colonies.
Significance statement
Just as in humans, animals living in large groups must contend with infectious diseases. Social insects such as honey bees have evolved a range of behavioural and organisational defences against disease, collectively termed ‘social immunity’. Here, we describe experiments in which we introduced immune-stimulated bee workers into hives to study social immunity. We find that bees that were wounded or immune-challenged were more likely to leave the hive—resulting in their death—compared to healthy controls. Some of the bees leaving the hive were ejected by other workers, while some left the hive seemingly by choice: we thus find evidence for both ‘banishment’ of immune-challenged bees and self-imposed exile. Furthermore, using experiments transferring chemical signals between healthy and immune stimulated bees, we establish that the latter are identified for banishment by the chemicals present on their body surface.
The Central Australian desert ant
Melophorus bagoti
maintains ground-nesting colonies in the semi-desert habitat. These ants manage waste by dumping items outside the nest. To examine this process, ...we placed organic and non-organic materials that are associated with either low or high pathogenic risk around or into the nest and observed the nest’s response. We found that generally, ants dumped high-pathogenic-risk materials (dead larvae, dead ants of the colony, foraged food, moth, and non-nest cicada exoskeleton) further from the nest than low-pathogenic-risk ones (sand, buffel grass, cookies), with the exception of (organic) larval shells from their own nest, which were also dumped close to the nest. This pattern of dumping suggests that these ants choose their dumping distance based on how spoilable the experimental materials are.
Abstract
Bee queen breeding was conducted for local and Carniolan honey bee strains, as well as hybrids resulting from cross-pollination, using both natural and artificial insemination methods. The ...hygienic behavior test was conducted using liquid nitrogen freezing method. The results showed that the hybrid bee strain T3 outperformed with detection and removal rates of 92.66% and 87.50% respectively, 48 hours after the study, regardless of the insemination method. The results also demonstrated the superiority of the natural insemination method, regardless of the studied strain, with detection and removal rates of 85.66% and 78.66% respectively, 48 hours after the killing process. The results also showed the interaction between the bee strain and the insemination method, 48 hours after the killing process, with significant superiority for treatment T2A1 in terms of detection and removal rates at 98.00% and 96.66% respectively. It was followed by treatment T3A2, which had no significant difference in detection rate (94.33%) and a removal rate of 89.00%, which was not significantly different from treatment T3A1 with a removal rate of 86.00%.
Leaf-cutter ants (
Atta
and
Acromyrmex
species) exhibit complex social organizations that have fascinated scientists for decades. The leaf-cutter ants belong to a subgroup of fungus-growing ants, ...which live with fungus inside their nests. The behaviours exhibited by these ants are closely linked to their social organization, which involves intricate division of labour, caste systems, and cooperative tasks. This review article provides an overview of the behaviors associated with the social organization of leaf-cutter ants. It explores various aspects of their social organization, including foraging behavior, hitchhiking behaviour, hygienic behaviour, social organization and environmental influences. The leaf cutter ants have the instinct to forage, as they walk around the nest to cut leaf fragments from plants, then transport those fragments with their jaws and go back to the nest to cultivate a special fungus garden within the colony. By synthesizing existing knowledge, this review highlights the intricate relationships between behaviors and the social structure of leaf-cutter ants, shedding light on the underlying mechanisms and evolutionary implications. Furthermore, it identifies research gaps and proposes future directions for studying leaf-cutter ant behaviors, including emerging techniques and interdisciplinary approaches. The behaviors correlating with the social organization of leaf-cutter ants showcase the intricate mechanisms underlying their highly organized societies. In conclusion, this review contributes to our understanding of the fascinating behaviors exhibited by leaf-cutter ants and their implications in the broader context of social insect societies.
Hygienic behaviour is a group defence in which dead or diseased individuals are excluded. In the honeybee, Apis mellifera, hygienic behaviour refers to uncapping and removing dead and diseased larvae ...and pupae from sealed brood cells. We quantified removal of freeze-killed and chalkbrood-infected larvae from open cells in 20 colonies. We also measured removal of freeze-killed brood from sealed cells. Study colonies ranged from non-hygienic to fully hygienic (52–100% removal within 2 days). All larvae killed in open cells were removed. This shows that all colonies, including those with low hygienic behaviour against dead brood in sealed cells, are highly hygienic against dead brood in open cells and suggests that low hygienic behaviour against dead brood in sealed cells is a trait in its own right. This may also contribute to understanding why hygienic behaviour is uncommon in A. mellifera, which is puzzling as it reduces several diseases without detrimental effects. In particular, the result provides indirect support for the hypothesis that there are two adaptive peaks conferring disease resistance: (i) high hygienic behaviour: diseased brood are removed quickly, in some cases before becoming infective; (ii) low hygienic behaviour: diseased brood remain isolated within sealed cells.
This article is part of the Theo Murphy meeting issue ‘Evolution of pathogen and parasite avoidance behaviours'.
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