In 2017, the European Commission initiated the EurBeST study to explore the possibilities of using selective breeding of honey bees to increase Varroa resistance traits. One of the specific aims of the study was to assess the process of honey bee queen breeding through an economic analysis. The methodology for calculating the costs of queen production (queen rearing and mating), colony evaluation and expenses for estimating breeding values is based on the Cost of Production (CoP). Cost data were collected via tailor-made questionnaires and interviews performed in five European countries (France, Germany, Greece, Italy, and Poland). The sample population consisted of 20 queen producers and 20 performance testers who participated in the study. The results showed that the average costs for queen production amounted to 22.58 per queen, ranging from 8.22 in Poland to 37.30 in France. The difference between the selling price and the production cost was on average 3.08 per queen, ranging from 15.86 in Germany to -12.30 in France. On average, the colony evaluation costs were 193.40 per colony. The average cost for breeding value estimation per queen was 8.09 . Thus, the average total cost per selected queen was 224 . The selective breeding of honey bees is an efficient way to increase productivity, reduce colony losses, improve bee health and enable profitable operations, but it is expensive, is usually promoted, practiced and implemented by scientists and researchers, and in most cases is financed by external sources.

Here we cover a wide range of methods currently in use and recommended in modern queen rearing, selection and breeding. The recommendations are meant to equally serve as standards for both scientific and practical beekeeping purposes. The basic conditions and different management techniques for queen rearing are described, including recommendations for suitable technical equipment. As the success of breeding programmes strongly depends on the selective mating of queens, a subchapter is dedicated to the management and quality control of mating stations. Recommendations for the handling and quality control of queens complete the queen rearing section. The improvement of colony traits usually depends on a comparative testing of colonies. Standardized recommendations for the organization of performance tests and the measurement of the most common selection characters are presented. Statistical methods and data preconditions for the estimation of breeding values which integrate pedigree and performance data from as many colonies as possible are described as the most efficient selection method for large populations. Alternative breeding programmes for small populations or certain scientific questions are briefly mentioned, including also an overview of the young and fast developing field of molecular selection tools. Because the subject of queen rearing and selection is too large to be covered within this paper, plenty of references are given to facilitate comprehensive studies.

Honey bees (Apis mellifera) have a peculiar and complex reproductive biology, with queens being polyandrous and mating with several drones during one or more mating (nuptial) flights in so-called drone congregation areas. Observing the virgin queens' and drones' flight behaviour provides data to understand and interpret a portion of the honey bees' complex reproductive process. Observing the behaviour of the virgin queens on the hive entrance also serves to estimate the distance from the mating place or potential drone congregation areas (DCAs) as well as to detect the presence of airborne drones in the area.In this paper, we provide a detailed description of the methodology used for observing queens' and drones' flights during the period of expected mating. In addition, we provide information about required equipment, tools as well as step by step description of the observation and recordkeeping process.

Click to increase image sizeClick to decrease image size Disclosure statementNo potential conflict of interest was reported by the authors.

The parasitic mite Varroa destructor (Anderson & Trueman) spends the dispersal phase of its life cycle on adult honeybees (Apis mellifera L.). The meaning of this phase for both bees and mites is still not well understood. This especially applies to prolonged dispersal phases as a result of brood interruptions. Hence, it is highly important to unravel this phase for understanding the underlying biological mechanisms and implementing this knowledge in beekeeping practice and research efforts. We investigated the effects of brood interruptions on honeybee colonies and the mites naturally infesting them. Reproduction parameters, brood infestation and recapping frequency were monitored over 60 days after brood interruptions of varying durations. Our results show that recapping frequency and mite non-reproduction increased during the interruption of egg laying. The duration of interruption and the time elapsed afterwards additionally affected the occurrence of reproductive failure. Hence, the reproduction of mites was affected by brood breaks immediately and in the long run.

In this study, we investigated the effect of queen caging on honey bee colonies’ post-treatment development and the optimal timing of method application on honey production during the main summer nectar flow. We conducted the study in nine apiaries (N = 9) across six Mediterranean countries, with a total of 178 colonies. The colonies were divided into three test groups: QC1, QC2, and C. The QC1 group involved queens caged for a total of 28 days before the expected harvesting day. In the QC2 group, queens were caged for 28 days, but only 14 days before the expected harvesting day. The C group consisted of queens that were not caged, and the colonies received common local treatments. In both the QC1 and QC2 groups, the colonies were treated with a 4.2% oxalic acid (OA) solution by trickling after the queen release. Our findings revealed no significant adverse effects (p > 0.05) on colony strength at the end of the study resulting from queen caging. However, significantly lower amounts of honey were extracted from the QC1 group compared to both the QC2 group (p = 0.001) and the C group (p = 0.009). Although there were no initial differences in Varroa destructor infestation between the groups, ten weeks later, a significantly higher infestation was detected in the C group compared to both the QC1 group (p < 0.01) and the QC2 group (p = 0.003). Overall, our study demonstrates that queen caging, in combination with the use of OA, is an effective treatment for controlling V. destructor. However, the timing of caging plays a crucial role in honey production outcomes.

The selection of honeybee strains resistant to the ectoparasitic mite Varroa destructor is generally considered as one of the most sustainable ways of coping with this major bee parasite. Thus, breeding efforts increasingly focus on resistance parameters in addition to common beekeeping traits like honey yield and gentleness. In every breeding effort, the success strongly depends on the quantifiability and heritability of the traits accounted. To find the most suitable traits among the manifold variants to assess Varroa resistance, it is necessary to evaluate how easily a trait can be measured (i.e., testing effort) in relation to the underlying heritability (i.e., expected transfer to the following generation). Various possible selection traits are described as beneficial for colony survival in the presence of Varroa destructor and therefore are measured in breeding stocks around the globe. Two of them in particular, suppressed mite reproduction (SMR, sensu lato any reproductive failure of mother mites) and recapping of already sealed brood cells have recently gained increasing attention among the breeders because they closely resemble resistance mechanisms of some Varroa-surviving honeybee populations. However, it was still unknown whether the genetic background of the trait is sufficient for targeted selection. We therefore investigated the heritabilities and genetic correlations for SMR and REC, distinguishing between recapping of infested cells (RECinf) and all cells (RECall), on an extensive dataset of Buckfast and Carniolan stock in Germany. With an accessible h² of 0.18 and 0.44 for SMR and an accessible h² of 0.44 and 0.40 for RECinf, both traits turned out to be very promising for further selection in the Buckfast and Carnica breeding population, respectively.

Resistance traits of honeybees (Apis mellifera) against their major parasite Varroa destructor have fascinated scientists and breeders for long. Nevertheless, the mechanisms underlying resistance are still largely unknown. The same applies to possible interactions between host behaviours, mite reproduction and seasonal differences. Two resistance traits, reproductive failure of mites and recapping of brood cells, are of particular interest. High rates of recapping at the colony level were found to correspond with low reproductive success of mites. However, the direct effect of recapping on mite reproduction is still controversial and both traits seem to be very variable in their expression. Thus, a deeper knowledge of both, the effect of recapping on mite reproduction and the seasonal differences in the expression of these traits is urgently needed. To shed light on this host-parasite interaction, we investigated recapping and mite reproduction in full-grown colonies naturally infested with V. destructor. Measurements were repeated five times per year over the course of 3 years. The reproductive success of mites as well as the recapping frequency clearly followed seasonal patterns. Thereby, reproductive failure of mites at the cell level was constantly increased in case of recapping. Interestingly, this did not apply to the occurrence of infertile mites. In line with this, recapping activity in fertile cells was most frequent in brood ages in which mite offspring would be expected. Our results suggest that mite offspring is the main target of recapping. This, in turn, leads to a significantly reduced reproductive success of the parasite.

Click to increase image sizeClick to decrease image size AcknowledgementWe would like to thank Dr. Cecilia Costa, Prof. Dr. Sreten Andonov, Dr. Jakob Wegener, Mr. Thomas Galea, Assist. Prof. Marin Kovačić, and Mr. Jeremy Groome for the valuable suggestions for improvement of the article.Disclosure statementNo potential conflict of interest was reported by the authors.

The study was conducted to explore alternatives for mating control as a part of honey bee breeding programs for genetic improvement & conservation of local honey bee (Apis mellifera) populations in Croatia (HR), Macedonia (MK) and Slovenia (SI). We observed nuptial flights of 87 virgin queens (30 in HR, 35 in MK and 22 in SI) on potential sites. Mating success was related to the presence of drone producing colonies, but even at locations chosen for their isolation from known apiaries, mating success of 70% was achieved. On average, queens performed nuptial flights on 1.8 days in HR, 1.6 to 4.3 days in MK and 1.6 to 2.4 days in SI. Unsuccessful nuptial flights were two/threefold shorter than successful flights.

Die Milbe Varroa destructor ist ein global vorkommender, bienenspezifischer Ektoparasit und eine der größten Bedrohungen der westlichen Honigbiene (Apis mellifera L.). Die Ameisensäure ist eine der effektivsten organischen Säuren in der Varroamilbenbekämpfung, allerdings muss ihr Einsatz nach Wegfall der Standardzulassung in Deutschland im Rahmen der Verordnung (EU) 2019/6 (TierAMVO 2018) rechtlich neu bewertet werden. Diese Studie untersucht die Wirksamkeit und Nebenwirkungen einer 60%igen Ameisensäurebehandlung in verschiedenen handelsüblichen Verdunstersystemen unter kontrollierten Bedingungen. Im Versuch wurden zweizargige Bienenvölker einmalig entweder mit der herkömmlichen Standarddosierung (230 g) Ameisensäure oder versuchsweise mit doppelter Dosierung (460 g) mittels Liebig Dispenser® oder Nassenheider Professional®-Langzeitverdunster behandelt. Als Referenz zu einem zugelassenen Ameisensäure-Präparat wurde eine weitere Gruppe mit Formic Pro®-Gelstreifen behandelt, wohingegen die Negativkontrollgruppe keiner Behandlung ausgesetzt war. Anschließend wurde über einen Zeitraum von zwei Monaten kontinuierlich der Milbenabfall untersucht. Die Ergebnisse belegen eine hohe und zuverlässige Wirksamkeit von mehr als 95,00 % der Verdunster unter doppelter Ameisensäure-Dosierung, während die Behandlung mittels herkömmlicher Dosierung bei beiden Dispensern mittlere Wirksamkeiten von über 75,00 % erreichten. Die Effektivität der Formic Pro®-Gelstreifen lag im Mittel bei über 90,00 %. Dies belegt die hohe Wirksamkeit einer 60%igen Ameisensäure in der Verdunsterapplikation gegen die Varroa-Milbe. Um auch Nebenwirkungen dieser hohen Effektivität darzustellen, wurden im Behandlungszeitraum und bis zu 14 Tage danach der Bienentotenfall regelmäßig ausgezählt sowie Königinnenverluste notiert. Die Standarddosierung der Ameisensäure erzielte nicht mehr tote Bienen als die unbehandelte Kontrollgruppe, während die doppelte Dosierung und die Gelstreifen zu deutlich größeren Bienenverlusten führten. Erhöhte Königinnenverluste zeigten sich vor allem in der Gruppe der Formic Pro®-Streifen.

Honeybee health and the species' gut microbiota are interconnected. Also noteworthy are the multiple niches present within hives, each with distinct microbiotas and all coexisting, which we termed "apibiome". External stressors (e.g. anthropization) can compromise microbial balance and bee resilience. We hypothesised that (1) the bacterial communities of hives located in areas with different degrees of anthropization differ in composition, and (2) due to interactions between the multiple microbiomes within the apibiome, changes in the community of a niche would impact the bacteria present in other hive sections. We characterised the bacterial consortia of different niches (bee gut, bee bread, hive entrance and internal hive air) of 43 hives from 3 different environments (agricultural, semi-natural and natural) through 16S rRNA amplicon sequencing. Agricultural samples presented lower community evenness, depletion of beneficial bacteria, and increased recruitment of stress related pathways (predicted via PICRUSt2). The taxonomic and functional composition of gut and hive entrance followed an environmental gradient. Arsenophonus emerged as a possible indicator of anthropization, gradually decreasing in abundance from agriculture to the natural environment in multiple niches. Importantly, after 16 days of exposure to a semi-natural landscape hives showed intermediate profiles, suggesting alleviation of microbial dysbiosis through reduction of anthropization.

As usual in science, where one answer raises new questions, following our attempt to demystify the basic concept of honey bee breeding with our article The Basic Concept of Honey Bee Breeding Programs (Uzunov et al., 2017) questions were raised on details about the implementation of a breeding program.