Dorothea Brückner

Kin structure and the swarming behavior of the honey bee Apis mellifera

SummaryExperimental hives obtained from cordovan queens that were instrumentally inseminated with semen from one cordovan and one Italian drone were set up and allowed to swarm. Cordovan provides a resessive genetic marker system (cuticle color) so that the workers from the cordovan and Italian male lines are distinguishable. Our results show that these patrilineal worker groups segregate non-randomly during colony fission and this segregation cannot be explained by observed age structure. Evidence of innate kin recognition in bees has been previously established. We argue that kin recognition could be responsible for the observed non-random grouping of kin during swarming.

Conditioning honeybees to discriminate between heritable odors from full and half sisters

SummaryDifferential conditioning of the proboscis extension reflex in honeybees is used to assess whether worker honeybees can be trained to discriminate between volatile odors emanating from different kin groups consisting of 2 or 20 workers. These odor source group workers are all reared and maintained under identical environmental conditions. They are the progeny of a queen that has been instrumentally inseminated so that eclosing adult workers can be sorted into colormorph full sister patrilines (workers are half sisters across patrilines). We demonstrate that workers are able to discriminate between the odors from groups of 20 individuals only if the groups represent individuals from different patrilines. However, discrimination occurs between groups of 2 individuals even if groups do not represent different patrilines. A number of environmental control experiments are also conducted. From our results we infer that there is heritable variation in the production of volatile odors by worker honeybees at a level that can be detected by the workers.

Reduction of biochemical polymorphisms in honeybees (Apis mellifica)

Elektrophoretische Untersuchungen zum Enzympolymorphismus der Honigbiene (Apis mellifica) ergaben, dass alle untersuchten Individuen, Tiere aus 4 Rassen, monomorph für Malatdehydrogenase, Esterase und Phosphoglucomutase waren.

Projection pattern of poreplate sensory neurones in honey bee worker, Apis mellifera L. (Hymenoptera : Apidae)

Abstract The projections of olfactory receptor cells of the poreplate sensilla were studied in the worker honey bee, Apis mellifera L. (Hymenoptera : Apidae) by filling single sensilla iontophoretically with cobalt chloride. Successful fillings of individual sensilla lead to staining of one to 22 sensory neurones. All stained receptor cell axons are uniglomerular. Seven fillings of poreplates from the 5th flagellar segment in different animals were compared to analyse the distribution patterns of the receptor cell axons in the antennal lobe. The sensory neurones of individual poreplates project to widely distributed glomeruli in the antennal lobe. The projection patterns of different poreplates are not the same, but may be overlapping.

Hoarding Behaviour and Life Span of Inbred, Non-Inbred and Hybrid Honeybees

SummaryCaged groups of 50 newly emerged workers (Apis mellifera carnica) stored the sugar solution provided (and in other experiments honey) in empty comb in their cages. On average, non-inbred workers took the food significantly faster than inbred workers, and hybrid workers took it faster than inbred workers of their parental lines. These results are discussed with respect to earlier results showing a difference in recruiting ability between inbred and non-inbred colonies.On average non-inbred workers lived longer than inbred workers, and hybrid workers longer than workers from their parental lines.Implications are discussed of inbreeding depression and heterosis, for both hoarding behaviour and length of life of workers, in relation to the theory of genetic load in haplo-diploid systems.

Variability of chemosensory stimuli within honeybee (Apis mellifera) colonies: Differential conditioning assay for discrimination cues

Differential training of honeybee workers using the proboscis extension reflex is applied to the problem of evaluating compounds that may potentially provide cues for kin recognition in the honeybeeApis mellifera. These cues were obtained by contaminating glass rods and steel needles with different materials found in the hive. In particular it is shown that workers discriminate between: cuticular waxes from different adult workers; eggs from the same and different hives; similar aged larvae within the same hive; and needles contaminated with the Nasonov gland secretions of different adult workers. It appears that some of these differences are due to phenotypic variation among individuals that cannot be directly attributed to environmental factors.

Exploitation of Dichrostachys cinerea, Vitellaria paradoxa, Persea americana and Securidaca longepedunculata flowers by Apis mellifera adansonii Latreille (Hymenoptera: Apidae) at Dang (Ngaoundéré, Cameroon)

In Cameroon, the demand for hive products is growing. Honey and pollen yields are low in the country, partly because of the poor knowledge of the apicultura! value of the flora. To determine the apicultural value of Dichrostachys cinerea (L.), Vitellaria paradoxa Gaertn. F., Persea americana Mill. and Securidaca longepedunculata Fres., Apis mellifera adansonii Latreille activity was observed on the flowers of these plants in Ngaoundéré, from December 2001 to May 2002 and from December 2002 to May 2003. The flowers of each plant species were prospected at least 4 days per month, between 0700 and 1800 h, for recording of the nectar and/or pollen foraging behaviour of A. m. adansonii workers. Results show that A. m. adansonii harvest nectar and pollen of V paradoxa, P. americana and S. longepedunculata. The flowers of D. cinerea were visited for pollen only. The greatest number of workers foraging simultaneously on a plant varied from 34 (D. cinerea) to 1640 (P. americana). A. m. adansonii workers that visited flowers of a given plant species once remained with this nectar source throughout the observation period. Thus V. paradoxa, P. americana and S. longepedunculata could be cultivated and protected to increase honey production, whereas D. cinerea could enable bee-keepers to increase their pollen production as a hive product. During foraging, A. m. adansonii workers increased pollination possibilities of each of the plant species.

Dimorphic antennal systems in gynandromorphic honey bees, Apis Mellifera l. (Hymenoptera: Apidae)

Abstract Gynandromorphic honey bees, Apis mellifera (Hymenoptera: Apidae), were examined to determine characteristic morphological and anatomical features of the antennal system. The antennae of gynandromorphic individuals are predominantly worker or drone-like. Hybrid antennae, composed of female and male tissues, occur only rarely (7 out of 188 examined antennae). Depending on the mosaic pattern of the head, both antennae can be drone-like or worker-like, or one can be drone-like and the other worker-like. Examination of the antennal lobes of six characteristic specimens revealed that antennal lobes, which are innervated by drone-like antennae, always have drone-specific enlarged tracts and macroglomerular complexes, whereas antennal lobes innervated by worker-like antennae always are composed of normally sized glomeruli. Thus, there is a strict correlation between the sexual morphology of the antennae and the sexual organization of the antennal lobe neuropil. In one antennal lobe, innervated by a hybrid antenna, we found a hypertrophied glomerulus, certainly homologous to one of the macroglomerular complexes in drone-like antennal lobes.jy 1999 Elsevier Science Ltd. All rights reserved.

Pollination efficiency of Apis mellifera adansonii (Hymenoptera: Apidae) on Callistemon rigidus (Myrtaceae) flowers at Dang (Ngaoundéré, Cameroon)

To evaluate the impact of the honeybee Apis mellifera adansonii Latreille on fruit and seed yields of Callistemon rigidus R. Br. 1819, its foraging and pollinating activities were studied in Ngaoundéré for two seasons (June–August 2009 and July–September 2010). Each year, observations were made on 120 inflorescences per treatment. The treatments included unlimited flower access by all visitors, bagged flowers to deny all visits and limited visits by A. m. adansonii only. In addition, all flower visitors were recorded. The worker bee’s seasonal rhythm of activity its foraging behaviour on flowers, its pollination efficiency, the fruiting rate, the number of seeds per fruit and the percentage of normal seeds were recorded. Individuals from five and ten insect species that visited C. rigidus flowers were recorded in 2009 and 2010, respectively. Apis mellifera adansonii was the most frequent, followed by Myrmicaria opaciventris Emery. Apis mellifera adansonii intensely and preferably foraged for nectar. The fruiting rate, the number of seeds per fruit and the percentage of normal seeds of unprotected inflorescences were significantly higher than those of inflorescences protected from insects. Apis mellifera adansonii foraging resulted in a significant increase in the fruiting rate by 92.04% in 2009 and 64% in 2010, as well as the number of seeds per fruit by 38.67% in 2009 and 59.16% in 2010, and the percentage of normal seeds by 84.67% in 2009 and 82.30% in 2010. Cultivation of C. rigidus plants could be recommended to increase seeds, fruits and honey production.

Behavioural response of drone honey bees, Apis mellifera carnica and Apis mellifera scutellata, to worker-produced pheromone components

SUMMARY To investigate the behavioural response of drone honey bees, Apis mellifera carnica and Apis mellifera scutellata, to the pheromone components isopentyl acetate (IPA) and geraniol, and the non-pheromone octanal, we conducted three different types of experiment: (1), in a glass arena; (2), in a Y-shaped maze; and (3), in a classical conditioning test. IPA caused arousal (more walking and wing beating) and avoidance, and geraniol caused arousal and attraction for drones of both subspecies. In the conditioning experiment the learning success of the drones was high for geraniol, medium for octanal and low for IPA.