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Friedrich-Wilhelm-Lübke-Koog, Germany

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

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. Source

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

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. Source

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

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. Source

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 Source

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

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 . Source

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