Bee Health Research (National Honey Board Production Research)
2007 Research Projects
Contaminants in High Fructose Corn Syrup and Their Possible Effects on Bees
Blaise LeBlanc
Carl Hayden Bee Research Center
HFCS samples were analyzed for metallic impurities, the pH of the syrup and how the levels of HMF vary with time, temperature and pH of the syrup. Researchers studied the caustic properties of the HMF samples by placing the samples in different containers made of materials that would be common storage vessels and analyzed these samples for the formation of HMF. Toxicity trials were performed with bees subjected to HMF and mercury (Hg). Hg was selected because it is a heavy metal with neurotoxic properties.
There is one paper published from this study (see below) and another due to be published in which Hg was found in domestic HFCS samples. “Formation of Hydroxymethylfurfural in Domestic High-Fructose Corn Syrup and Its Toxicity to the Honey Bee (Apis mellifera),” Blaise W. LeBlanc, Gillian Eggleston, Diana Sammataro, Charles Cornett, Renee Dufault, Thomas Deeby and Eldwin St. Cyr, J. Agric. Food Chem., Publication Date (Web): July 31, 2009
http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=242171
2007 Research Projects
Cyclodextrins as Carriers of Essential Oils for Varroa Control in Honeybees
Blaise LeBlanc
Carl Hayden Bee Research Center
“β-Cyclodextrins as Carriers of Monoterpenes into the Hemolymph of the Honey Bee (Apis mellifera) for Integrated Pest Management,” Journal of Agricultural and Food Chemistry, 2008, 56 (18), pp 8565–8573
Abstract
The Varroa mite (Varroa destructor) is becoming ubiquitous worldwide and is a serious threat to honey bees. The cultivation of certain food crops are at risk. The most noted acaricides against Varroa mites are tau-fluvaninate and coumaphos, but the mites are showing resistance. Since these insecticides are used in the proximity of honey, it is desirable to use natural alternatives. Monoterpenoids such as thymol and carvacrol, that are constituents of oil of thyme and oil of origanum, show promise as acaricides against the Varroa mite (Varroa destructor), but the delivery of these compounds remains a challenge due to the low water solubility and uncontrolled release into the colony. β-cyclodextrin (β-CD) inclusion complexes of thymol, oil of origanum, and carvacrol were prepared on a preparative scale. Competitive binding was studied by fluorescence spectroscopy by using 6-p-toluidinylnaphthalene-2-sulfonate as a fluorescent probe. The complexes were characterized, and the competitive binding described by 1H and 13C NMR spectroscopy chemical shifts. The toxicity of β-CD and the prepared complexes in enriched sucrose syrup was studied by conducting caged honey bee (Apis mellifera) feeding trials. After the first and second weeks of feeding, hemolymph and gut tissue samples were acquired from the caged bee study. The levels of thymol and carvacrol were quantified by solid-phase microextraction gas chromatography mass spectroscopy, using an optimized procedure we developed. High (mM) levels of thymol and carvacrol were detected in bee tissues without any imposed toxicity to the bees, in an effort to deter Varroa mites from feeding on honey bee hemolymph.
2007 Research Projects
Treatment and Monitoring Regimes to Ensure colony Vigor and Prevent Fall Dwindle Disease
Dennis vanEngelsdorp
Pennsylvania State University
What was termed “Fall Dwindle Disease” became “Colony Collapse Disorder.” This study set out to test various comb treatment strategies, chemotherapy options, and other management systems to prevent colony mortality and the onset of CCD specifically. Because of the devastating effects of CCD and the high media visibility, this project grew to include larger sampling, additional funding amounting to 8 times what the NHB contributed, and the help of Jeff Pettis at the USDA-ARS Beltsville laboratory.
145 colonies were established to test the effects of migratory versus stationary status, and different types of comb:
- Control: No treatment (and having died previously from CCD)
- Comb irradiated prior to package introduction
- Comb fumigated with Acetic Acid prior to package introduction
- Comb containing honey
The recommendations resulting from the study were:
- Beekeepers should irradiate equipment from dead out colonies
- Beekeepers should consider replacing Australian package queens with U.S.-bred queens.
- Beekeepers should consider treating all installed packages for nosema disease.
Additional results from this study led to NHB funding for the 2008 “Nutritional Changes” study.
2007 Research Projects
The Benefits of Propolis to Honey Bees
Marla Spivak
University of Minnesota
“In vitro study of the antimicrobial activity of Brazilian propolis against Paenibacillus larvae,” Journal of Invertebrate Pathology, Volume 97, Issue 3, March 2008, Pages 273-281
Abstract The honey bee disease American foulbrood (AFB) is a serious problem since its causative agent (Paenibacillus larvae) has become increasingly resistant to conventional antibiotics. The objective of this study was to investigate the in vitro activity of propolis collected from various states of Brazil against P. larvae. Propolis is derived from plant resins collected by honey bees (Apis mellifera) and is globally known for its antimicrobial properties and particularly valued in tropical regions. Tests on the activity of propolis against P. larvae were conducted both in Brazil and Minnesota, USA using two resistance assay methods that measured zones of growth inhibition due to treatment exposure. The propolis extracts from the various states of Brazil showed significant inhibition of P. larvae. Clear dose responses were found for individual propolis extracts, particularly between the concentrations of 1.7 and 0.12 mg propolis/treatment disk, but the source of the propolis, rather than the concentration, may be more influential in determining overall activity. Two of the three tested antibiotics (tylosin and terramycin) exhibited a greater level of inhibition compared to most of the Brazilian samples, which could be due to the low concentrations of active compounds present in the propolis extracts. Additionally, the majority of the Brazilian propolis samples were more effective than the few collected in MN, USA. Due to the evolution of resistance of P. larvae to conventional antibiotic treatments, this research is an important first step in identifying possible new active compounds to treat AFB in honey bee colonies.
2007 Research Projects
Honey Industry
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