Institute for Bee Research Hohen Neuendorf

Friedrich-Wilhelm-Lübke-Koog, Germany

Institute for Bee Research Hohen Neuendorf

Friedrich-Wilhelm-Lübke-Koog, Germany
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Crailsheim K.,University of Graz | Brodschneider R.,University of Graz | Aupinel P.,French National Institute for Agricultural Research | Behrens D.,Martin Luther University of Halle Wittenberg | And 3 more authors.
Journal of Apicultural Research | Year: 2013

Originally, a method to rear worker honey bee larvae in vitro was introduced into the field of bee biology to analyse honey bee physiology and caste development. Recently, it has become an increasingly important method in bee pathology and toxicology. The in vitro method of rearing larvae is complex and can be developed as an art by itself, especially if the aim is to obtain queens or worker bees which, for example, can be re-introduced into the colony as able members. However, a more pragmatic approach to in vitro rearing of larvae is also possible and justified if the aim is to focus on certain pathogens or compounds to be tested. It is up to the researcher(s) to decide on the appropriate experimental establishment and design. This paper will help with this decision and provide guidelines on how to adjust the method of in vitro rearing according to the specific needs of the scientific project. Copyright © IBRA 2013.

Zakour M.K.,Institute for Bee Research Hohen Neuendorf | Bienefeld K.,Institute for Bee Research Hohen Neuendorf
Journal of Apicultural Research | Year: 2014

The principles of valuing biodiversity are well understood, but methodologies are not yet adequate for enhancing the diversity of honey bee genetic resources. Genetic diversity is generally assumed to be an important barrier against changing environmental conditions, yet some indigenous honey bee breeds are at risk of becoming extinct. The causes of this often stem from development policies in developing countries in the Middle East and other parts of the world, which have largely ignored well-adapted local breeds. The focus instead has been on the introduction of "improved", exotic ones. Hence, one potential way to ensure survival and promote conservation is by establishing selection programmes that improve efficiency and behaviour in endangered breeds, whilst maintaining their environmental adaptation. However, to develop appropriate genetic models and breeding strategies, genetic aspects and population peculiarities of honey bees must be taken into account. This study aimed at outlining all information needed to plan an efficient honey bee breeding programme, and illustrate this with the example of the endangered Syrian honey bee (Apis mellifera syriaca). © IBRA 2014 .

Costa C.,Italian Agricultural Research Council | Lodesani M.,Italian Agricultural Research Council | Bienefeld K.,Institute for Bee Research Hohen Neuendorf
Apidologie | Year: 2012

The aim of this study was to reveal the existence of locally adapted populations of Apis mellifera ligustica. To this end, the spring development and honey production of three sources of A. mellifera ligustica were compared in three Italian habitats differing in flora and climate, in order to investigate interactions between origin of the bees and test environment (GxE). The results from a total of 165 colonies showed significant GxE for the considered traits. Interestingly, for two of the considered origins, colonies produced most when kept in their region of origin. Honey production can be considered a measure of adaptation to environment as it reflects the ability of a colony to make the most profit of the plant nectar sources present in its surroundings. Thereby, this study shows that populations of locally adapted honeybees still exist in Italy, despite widespread use of commercially produced honeybee queens. © 2012 INRA, DIB and Springer-Verlag, France.

Fries I.,Swedish University of Agricultural Sciences | Chauzat M.-P.,Anses | Chen Y.-P.,U.S. Department of Agriculture | Doublet V.,Martin Luther University of Halle Wittenberg | And 11 more authors.
Journal of Apicultural Research | Year: 2013

Methods are described for working with Nosema apis and Nosema ceranae in the field and in the laboratory. For fieldwork, different sampling methods are described to determine colony level infections at a given point in time, but also for following the temporal infection dynamics. Suggestions are made for how to standardise field trials for evaluating treatments and disease impact. The laboratory methods described include different means for determining colony level and individual bee infection levels and methods for species determination, including light microscopy, electron microscopy, and molecular methods (PCR). Suggestions are made for how to standardise cage trials, and different inoculation methods for infecting bees are described, including control methods for spore viability. A cell culture system for in vitro rearing of Nosema spp. is described. Finally, how to conduct different types of experiments are described, including infectious dose, dose effects, course of infection and longevity tests. Copyright © IBRA 2013.

Zakour M.K.,Institute for Bee Research Hohen Neuendorf | Bienefeld K.,Institute for Bee Research Hohen Neuendorf
Journal of Apicultural Science | Year: 2013

To separate gentle from defensive bee types, a rating scale is the most reliable, economical, and practical evaluation system. In initiating a breeding programme for the indigenous Syrian honeybee Apis mellifera syriaca, a typical representative of the endangered subspecies of the Middle East, multiple measurements were used to generally monitor this behavior and verify whether the international Apimondia recommendations are suitable for such subspecies. A total of 72 beekeepers and three breeding centers provided performancetesting results from 969 colonies distributed throughout 75 apiaries in Syria. Each colony was tested, on average, 4.73 times (4584 records total). The defensive behavior of A. m. syriaca was found to be very aggressive (1.48 scored by a system ranging from 1 (aggressive) to 4 (gentle)). The low repeatability (0.19) of defensive behavior estimated using restricted maximal likelihood analysis and the low and skewed variation of the trait indicate that other scoring systems are expected to be more efficient for selective breeding towards gentle behavior.

Chakroborty N.K.,Free University of Berlin | Chakroborty N.K.,National Brain Research Center Manesar | Bienefeld K.,Institute for Bee Research Hohen Neuendorf | Menzel R.,Free University of Berlin
Apidologie | Year: 2015

Odor learning and odor discrimination were tested in a line of honeybees selected for increased hygienic behavior (HB) against the Varroa mite and compared with control bees (CB). Olfactory proboscis extension conditioning was used to quantify learning, discrimination, and generalization. Retention tests were performed after 1 h and after 1 day to probe the stability of memory. HB and CB did not differ in their learning, discriminating, generalizing, and remembering behavior when pairs of floral odors and pairs of sting pheromone and floral odor were tested. Colony odor used as a background odor during learning and discrimination reduced the performance in both groups, possibly due to an adaptation effect. This effect was found to be particularly strong in CB. In both groups of test bees, no learning was found if wax caps of Varroa-infected and Varroa-uninfected cells were used as test stimuli, possibly because of the common odors. Volatile odors from Varroa-infected and noninfected pupae, however, were learned and discriminated indicating that the volatile signals are strong enough to override the similar cues of pupae. HB performed somewhat better than CB when infected pupae were used as the rewarded stimulus, but the difference between the two groups of test bees was small. Taken together, we conclude that odor learning and discrimination do not differ between HB and CB as long as general odors are involved, but when specific odor profiles from infected pupae are used as the reinforced signal, then a slightly better performance is seen in HB. © 2015, INRA, DIB and Springer-Verlag France.

Bienefeld K.,Institute for Bee Research Hohen Neuendorf | Zautke F.,Institute for Bee Research Hohen Neuendorf | Gupta P.,Institute for Bee Research Hohen Neuendorf | Gupta P.,Free University of Berlin
Journal of Apicultural Research | Year: 2016

Honey bees manifest a rich repertoire of behavioral traits. These traits contribute to the successful establishment of a highly evolved social organization in the honey bee. In this study, we describe a novel observational methodology using infrared camera technology for the long-term, undisturbed investigation of behavioral traits of honey bee. An illustration of this methodology is provided through observations of hygienic behavior in response to varroa infestation. Using our method, we show that honey bee workers exhibit a systematic sequence of behavioral activities during the performance of hygienic behavior. The results of this study support the hypothesis that the uncapping of varroa-parasitized brood cells is driven by abnormal odors from the parasitized pupae. © 2016 International Bee Research Association

Bauer D.,Institute for Bee Research Hohen Neuendorf | Bienefeld K.,Institute for Bee Research Hohen Neuendorf
Naturwissenschaften | Year: 2013

The nests of European honeybees (Apis mellifera) are organised into wax combs that contain many cells with a hexagonal structure. Many previous studies on comb-building behaviour have been made in order to understand how bees produce this geometrical structure; however, it still remains a mystery. Direct construction of hexagons by bees was suggested previously, while a recent hypothesis postulated the self-organised construction of hexagonal comb cell arrays; however, infrared and thermographic video observations of comb building in the present study failed to support the self-organisation hypothesis because bees were shown to be engaged in direct construction. Bees used their antennae, mandibles and legs in a regular sequence to manipulate the wax, while some bees supported their work by actively warming the wax. During the construction of hexagonal cells, the wax temperature was between 33.6 and 37.6 C. This is well below 40 C, i.e. the temperature at which wax is assumed to exist in the liquid equilibrium that is essential for self-organised building. © 2012 Springer-Verlag Berlin Heidelberg.

Wegener J.,Institute for Bee Research Hohen Neuendorf | May T.,University Campus | Kamp G.,University Campus | Bienefeld K.,Institute for Bee Research Hohen Neuendorf
Cryobiology | Year: 2014

Honeybee biodiversity is under massive threat, and improved methods for gamete cryopreservation could be a precious tool for both the in situ- and ex situ-conservation of subspecies and ecotypes. Recent cryoprotocols for drone semen have improved the viability and fertility of frozen-thawed semen by using increased diluent:semen-ratios, but there is still much room for progress. As semen cryopreserved after dilution often appeared hyperactive, we speculated that the disruption of sperm-sperm interactions during dilution and cryopreservation could reduce the fertile lifespan of the cells. We therefore developed protocols to reduce admixture, or abolish it altogether by dialyzing semen against a hypertonic solution of cryoprotectant. Additionally, we tested methods to reduce the cryoprotectant concentration after thawing. Insemination of queens with semen cryopreserved after dialysis yielded 49%, 59% and 79% female (=stemming from fertilized eggs) pupae in three separate experiments, and the numbers of sperm found in the spermathecae of the queens were significantly higher than those previously reported. Post-thaw dilution and reconcentration of semen for cryoprotectant removal reduced fertility, but sizeable proportions of female brood were still produced. Workers stemming from cryopreserved semen did not differ from bees stemming from untreated semen with regard to indicators of fluctuating asymmetry, but were slightly heavier. Cryopreservation after dialysis tended to increase the proportion of cells with DNA-nicks, as measured by the TUNEL-assay, but this increase appears small when compared to the baseline variations of this indicator. Overall, we conclude that cryoprotectant-addition through dialysis can improve the quality of cryopreserved drone semen. Testing of offspring for vitality and genetic integrity should continue. © 2014 Elsevier Inc.

PubMed | Heinrich Heine University Düsseldorf and Institute for Bee Research Hohen Neuendorf
Type: Journal Article | Journal: BMC research notes | Year: 2016

Hygienic behavior (HB) enables honeybees to tolerate parasites, including infection with the parasitic mite Varroa destructor, and it is a well-known example of a quantitative genetic trait. The understanding of the molecular processes underpinning the quantitative differences in this behavior remains limited.We performed gene expression studies in worker bees that displayed quantitative genetic differences in HB. We established a high and low genetic source of HB performance and studied the engagements into HB of single worker bees under the same environmental conditions. We found that the percentage of worker bees that engaged in a hygienic behavioral task tripled in the high versus low HB sources, thus suggesting that genetic differences may mediate differences in stimulated states to perform HB. We found 501 differently expressed genes (DEGs) in the brains of hygienic and non-hygienic performing workers in the high HB source bees, and 342 DEGs in the brains of hygienic performing worker bees, relative to the gene expression in non-hygienic worker bees from the low HB source group. Cell surface receptor ligand signal transduction in the high and negative regulation of cell communication in the low HB source were overrepresented molecular processes, suggesting that these molecular processes in the brain may play a role in the regulation of quantitative differences in HB. Moreover, only 21 HB-associated DEGs were common between the high and low HB sources.The better HB colony performance is primarily achieved by a high number of bees engaging in the hygienic tasks that associate with distinct molecular processes in the brain. We propose that different gene products and pathways may mediate the quantitative genetic differences of HB.

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