The European honey bee, Apis mellifera, is a primarily beneficial insect for mankind. It has been utilized by humans for thousands of years for the products and services it provides. Crop pollination and honey production are two of the most economically beneficial activities of the honey bee. Though they have been important for many centuries and immeasurable amounts of effort have been expended investigating the methods and means to harness their natural abilities, a far lesser amount of attention has been directed towards exploring their molecular makeup. These experiments involve identifying modification of gene transcription as a result of exposure to a pheromone or a parasite. This data will provide information on the general types of transcripts involved in the biochemical response of the honey bee to the two stimuli and will also provide specific candidates for further investigation of their potential role in downstream behavioral events.

Thesis (M. Sc. (Botany))--Rhodes University, 2003. / Title in graduation programme: The ecology of honey plants in the Eastern Cape.

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The honey bee is one of the most familiar insects in the world, and plays an important role in the global economy providing essential pollination services to crops, fruit trees and vegetables. However, honey bee health is severely threatened by the ectoparasitic mite Varroa destructor, which feeds on the hemolymph of pupal and adult bees, resulting in loss of nutrients and circulatory fluids, decreased overall body weight and eventually the death of the bees. To investigate the molecular defense mechanisms of the honey bee against varroa mite infestation, we employed DNA microarray analysis to compare gene expression of two contrasting honey bee colony phenotypes selected from the Saskatraz breeding program. One designated as G4 is susceptible to the varroa mite, while the other designated as S88 is highly tolerant to the varroa. Total RNAs were isolated from bees at two different stages, dark-eyed pupa and adult worker, infected or non-infected with varroa mites, and used for DNA microarray analysis. The results showed that distinct sets of genes were differentially regulated in the varroa-tolerant and varroa-susceptible honey bee phenotypes, with and without varroa infestation. In both phenotypes, there were more differentially-expressed genes identified at the pupal stage than at the adult stage, indicating that at the pupal stage honey bees are more responsive to the varroa infestation than adult bees. In the phenotype comparisons, substantially more differentially-expressed genes were found in the tolerant than susceptible line, indicating that the tolerant phenotype has an increased capacity to mobilize the expression of the genes in response to varroa mite infestation. Based on function, the differentially-expressed genes could be classified into groups that are involved in olfactory signal transduction, detoxification, metabolism and exoskeleton formation, implying several possible mechanisms for the host-parasite interaction and resistance. Quantitative RT-PCR was used to confirm the data obtained from the DNA microarray hybridization. Eleven out of twelve genes selected based on the microarray data showed consistent expression patterns measured by both methods. Overall, comprehensive evaluation of the gene expression of honey bees in response to the mite infestation by DNA microarray has revealed several possible molecular mechanisms for the host defense against the pest. Identification of highly differentially expressed genes between the two phenotypes provides potential biomarkers that can be used for breeding honey bees resistant to the varroa mite.

The goal of this study was to examine the impact of Africanization on the genetic structure of the Welder Wildlife Refuge feral honey bee population by scoring mtDNA and microsatellite polymorphisms. Adult honey bee workers, collected between 1991 and 2001, were screened for mtDNA using the cytochrome b/BglII, ls rRNA/EcoRI, and COI/HinfI PCR-based assays. The procedure allowed identification of four mitotypes: eastern European, western European, A. m. lamarckii, and A. m. scutellata. The relative frequencies of the four mitotypes changed radically during the 11-year period. Prior to immigration of Africanized honey bees, the resident population was essentially of eastern European maternal ancestry. The first colony of A. m. scutellata mitotype was detected in 1993. Between 1995 and 1996 there was a mitotype turnover in the population from predominantly eastern European to predominantly A. m. scutellata. From 1997 onward, most colonies (69 %) were of A. m. scutellata mitotype. The temporal change in mtDNA was paralleled by nuclear DNA. The 12 microsatellite loci analyzed indicated (1) the mechanism of Africanization of the Welder population involved both maternal and paternal bi-directional gene flow (hybridization) between European and Africanized honey bees; and (2) the resident panmitic European population was replaced by panmitic asymmetrical admixtures of A. m. scutellata and European genes. The steepest increase in the proportion of introgressed A. m. scutellata nuclear alleles occurred between 1994 and 1997. The post-Africanization gene pool was composed of a diverse array of recombinant classes with a substantial European genetic contribution (mean proportion of European-derived alleles was 37 % as given by mR estimator or 25 % as given by mY estimator, for 1998-2001). If European genes continue to be retained at moderate frequencies, then the Africanized population is best viewed as a "hybrid swarm" instead of "pure African". The most radical change in the genetic structure of the Welder Wildlife Refuge feral honey bee population (observed between 1995 and 1997) coincided with arrival of the parasitic Varroa mite. We suggest that Varroa likely hastened the demise of European honey bees and had a major role in restructuring the Welder Wildlife Refuge feral honey bee population.

The aim of the research is to assess various decrystallization techniques applied to honey of different biological origin, in order to reveal the processes occurring in honey during decrystallization and storage, and to assess the changing quality of honey and human allergy manifestation. The Research Tasks: 1. To investigate biological origin, physico-chemical, biochemical properties and relationship among several types of honey, to highlight the most valuable types of honey with reference to them. 2. To explore the influence of thermal and mechanical decrystallization on physical, chemical and biochemical properties of different biological origin honey. 3. To evaluate the dynamics of physicochemical and biochemical changes in differently decrystallized honey during storage. 4. To determine the optimal modes of honey thermal decrystallization friendly to honey valuable properties, the most favourable storage duration and conditions. 5. To reveal whether there is a difference in allergy caused by honey before and after heat treatment. / Darbo tikslas Įvertinti skirtingos biologinės kilmės medaus įvairių dekristalizavimo būdų galimybę, atskleisti dekristalizavimo ir sandėliavimo metu meduje vykstančius procesus, įvertinti kintančią medaus kokybę bei poveikį žmonių alergiškumui. Darbo uždaviniai 1. Ištirti skirtingų medaus rūšių botaninę-biologinę kilmę, fizikocheminius, biocheminius parametrus ir jų tarpusavio ryšius, remiantis jais išryškinti vertingiausios kilmės medaus rūšis. 2. Ištirti terminio ir mechaninio poveikio įtaką skirtingos biologinės kilmės medaus fizinėms, cheminėms bei biocheminėms savybėms. 3. Įvertinti įvairiais būdais dekristalizuoto medaus fizikocheminių ir biocheminių savybių kitimo dinamiką sandėliuojant. 4. Nustatyti optimalius dekristalizavimo režimus, tausojančius vertingąsias medaus savybes, optimalią sandėliavimo trukmę ir sąlygas. 5. Įvertinti skirtingos botaninės kilmės natūralaus bei termiškai apdoroto medaus įtaką žmonių alergiškumui.

Red sorrel is a perennial weed in wild blueberry fields that decreases yield. Multiple experiments were conducted to evaluate its impact on blueberry pollination, Botrytis blight incidence, and berry yield. Kerb applications did not significantly impact blueberry stem or floral bud formation. Removal of red sorrel with Kerb increased blueberry yield at both sites. However a double application had no difference than one application. Blueberry and red sorrel flowering overlapped and red sorrel pollen grains were found on blueberry flowers in both years at all sites. Red sorrel pollen grains increased the incidence of germinating spores in Petri dishes and this relationship was adequately modeled with a three parameter, exponential rise to a maximum. Red sorrel pollen significantly increased disease incidence on immature blueberry flowers. Honey bees foraged from blueberry and red sorrel flowers, but there was no evidence to suggest that they favored red sorrel flowers over blueberry flowers.

Thesis (M.S.)--Rhodes University, 2003. / Title from PDF t.p. (viewed on June 9, 2006). Includes bibliographical references (p. 110-122).

Made available in DSpace on 2015-03-03T11:52:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-08-29Bitstream added on 2015-03-03T12:07:11Z : No. of bitstreams: 1 000795971_20160919.pdf: 399845 bytes, checksum: d815b292ab3811ccc3c93ecacaef7f99 (MD5) Bitstreams deleted on 2016-09-19T11:17:06Z: 000795971_20160919.pdf,. Added 1 bitstream(s) on 2016-09-19T11:17:40Z : No. of bitstreams: 1 000795971.pdf: 814400 bytes, checksum: cd770b9f5a47f8607a20d444a4aa166b (MD5) / Um dos indicadores de qualidade do mel é o 5-hidroximetil-2-furfural (HMF). O HMF é produzido pelo aquecimento e envelhecimento do mel. A Comissão Internacional do Mel recomenda três métodos para a determinação do HMF em mel, o método de Winkler, o método de White e a determinação por CLAE. O método de Winkler utiliza a substância carcinogênica p-toluidina, a qual não está de acordo com os princípios da Química Verde. O presente estudo propôs para a determinação de HMF em mel, um método por análise por injeção em fluxo (FIA) usando o método de Winkler modificado, substituindo a p-toluidina por ácido p-aminobenzóico. A faixa linear foi de 1,00 a 40,0 mg L-1, o limite de detecção (LD) foi de 0,43 mg L-1 e o limite de quantificação 1,32 mg L-1. O método é eficiente e mais ambientalmente amigável na análise de HMF em mel. / One of the quality indicator for honey is 5-hydroxymethyl-2-furfural (HMF). The HMF is product by heating and aging of honey. The International Honey Commission recommends three methods for the determination of HMF in honey, the Winkler method, the White method, and determination by HPLC. The Winkler method uses the carcinogenic substance p-toluidine, which is not in agreement with the principles of Green Chemistry. The present study proposed for determination of HMF in honey, a flow injection analysis (FIA) method using a modified method of Winkler, replacing p-toluidine for p-aminobenzoic acid. The linear range was 1.00 to 40.0 mg L-1, the limit of detection (LD) was 0.43 mg L-1 and the limit of quantification (LQ) was 1.32 mg L-1. The method is efficient and most environmentally friendly in the analysis of HMF in honey.

5 p. / Both honey and sugar are carbohydrate, calorie-dense sweeteners. This article reviews similarities and differences of honey and sugar, and then answers the popular questions: “Is honey better than sugar?” and “What are cooking tips when substituting honey for sugar in recipes?”