RESUMEN
Honey bee colony feeding trials were conducted to determine whether differential effects of carbohydrate feeding (sucrose syrup (SS) vs. high fructose corn syrup, or HFCS) could be measured between colonies fed exclusively on these syrups. In one experiment, there was a significant difference in mean wax production between the treatment groups and a significant interaction between time and treatment for the colonies confined in a flight arena. On average, the colonies supplied with SS built 7916.7 cm(2) ± 1015.25 cm(2) honeycomb, while the colonies supplied with HFCS built 4571.63 cm(2) ± 786.45 cm(2). The mean mass of bees supplied with HFCS was 4.65 kg (± 0.97 kg), while those supplied with sucrose had a mean of 8.27 kg (± 1.26). There was no significant difference between treatment groups in terms of brood rearing. Differences in brood production were complicated due to possible nutritional deficiencies experienced by both treatment groups. In the second experiment, colonies supplemented with SS through the winter months at a remote field site exhibited increased spring brood production when compared to colonies fed with HFCS. The differences in adult bee populations were significant, having an overall average of 10.0 ± 1.3 frames of bees fed the sucrose syrup between November 2008 and April 2009, compared to 7.5 ± 1.6 frames of bees fed exclusively on HFCS. For commercial queen beekeepers, feeding the right supplementary carbohydrates could be especially important, given the findings of this study.
Asunto(s)
Apicultura , Abejas , Sacarosa , Zea mays , AnimalesRESUMEN
Fermentation by fungi converts stored pollen into bee bread that is fed to honey bee larvae, Apis mellifera, so the diversity of fungi in bee bread may be related to its food value. To explore the relationship between fungicide exposure and bee bread fungi, samples of bee bread collected from bee colonies pollinating orchards from 7 locations over 2 years were analyzed for fungicide residues and fungus composition. There were detectable levels of fungicides from regions that were sprayed before bloom. An organic orchard had the highest quantity and variety of fungicides, likely due to the presence of treated orchards within bees' flight range. Aspergillus, Penicillium, Rhizopus, and Cladosporium (beneficial fungi) were the primary fungal isolates found, regardless of habitat differences. There was some variation in fungal components amongst colonies, even within the same apiary. The variable components were Absidia, Alternaria, Aureobasidium, Bipolaris, Fusarium, Geotrichum, Mucor, Nigrospora, Paecilomyces, Scopulariopsis, and Trichoderma. The number of fungal isolates was reduced as an effect of fungicide contamination. Aspergillus abundance was particularly affected by increased fungicide levels, as indicated by Simpson's diversity index. Bee bread showing fungicide contamination originated from colonies, many of which showed chalkbrood symptoms.
Asunto(s)
Abejas/efectos de los fármacos , Hongos/efectos de los fármacos , Fungicidas Industriales/toxicidad , Própolis , Animales , Antiinfecciosos , Abejas/microbiología , Contaminación de Medicamentos , Hongos/aislamiento & purificación , Fungicidas Industriales/análisis , Própolis/químicaRESUMEN
Two kinds of experiments were conducted with Aethina tumida Murray larvae over four temperatures: "consumption" experiments, in which larvae and diet were weighed to determine food consumption rates under conditions of unlimited food and few conspecifics; and "competition" experiments, in which varying numbers of larvae were presented with the same amount of honey and pollen diet, and larval weight at final instar was used to determine competition effects. In consumption experiments temperature, diet and their interaction all had significant effects on the ratio of larval weight to the weight of food consumed, which was higher at 24 degrees C than at any other temperature. In competition experiments, three relationships were examined and modeled: that between the number of larvae per experimental unit and the average weight of those larvae; that between average larval and adult weights; and that between average adult weight and survivorship to adult (emergence rate). An exponential decay function was fit to the relationship between number of larvae per experimental unit and their average weight. Average adult weight was linearly correlated with larval weight. Likewise, emergence rates for adults < 11.6 mg in weight were linearly correlated with adult weights, but no significant relationship was observed for heavier adults. Using these relationships, the reproductive potential for A. tumida were estimated for a frame of honey and pollen. Information on resource acquisition by A. tumida will be useful in evaluating the impact of different factors on beetle population dynamics, such as bee hygienic behavior or control strategies used by the beekeeper.
Asunto(s)
Escarabajos/fisiología , Animales , Abejas/parasitología , Escarabajos/crecimiento & desarrollo , Conducta Competitiva , Dieta , Larva/crecimiento & desarrollo , Larva/fisiologíaRESUMEN
In this study, the carbohydrate composition of high-fructose corn syrups (HFCS) from commercial manufacturers as well as from beekeepers was characterized by GC-MS. Sucrose syrups (SS) were also included in this work for comparison. Fructosyl-fructoses and some unknown carbohydrates, which could correspond to fructosyl-glucoses, have been detected in HFCS for the first time, whereas SS were mainly characterized by the high contents of sucrose. Hydroxymethylfurfural (HMF) content of samples supplied by beekeepers was much more variable; the mean level of HMF was 64.61 ppm (+/-16.92 ppm, 95% CI ranging from 26.91 to 102.31 ppm). Syrups were used to feed caged bees and the resulting honeys produced were analyzed in order to determine their influence in carbohydrate composition. Fructosyl-fructoses were mainly detected in honeys from bees fed with HFCS, but not from those honeys coming from free-flying bees or bees fed with SS.
Asunto(s)
Abejas/fisiología , Fructosa/análisis , Miel/análisis , Zea mays/química , AnimalesRESUMEN
In the United States, high-fructose corn syrup (HFCS) has become a sucrose replacement for honey bees and has widespread use as a sweetener in many processed foods and beverages for human consumption. It is utilized by commercial beekeepers as a food for honey bees for several reasons: to promote brood production, after bees have been moved for commercial pollination, and when field-gathered nectar sources are scarce. Hydroxymethylfurfural (HMF) is a heat-formed contaminant and is the most noted toxin to honey bees. Currently, there are no rapid field tests that would alert beekeepers of dangerous levels of HMF in HFCS or honey. In this study, the initial levels and the rates of formation of HMF at four temperatures were evaluated in U.S.-available HFCS samples. Different HFCS brands were analyzed and compared for acidity and metal ions by inductively coupled plasma mass spectroscopy. Levels of HMF in eight HFCS products were evaluated over 35 days, and the data were fit to polynomial and exponential equations, with excellent correlations. The data can be used by beekeepers to predict HMF formation on storage. Caged bee studies were conducted to evaluate the HMF dose-response effect on bee mortality. Finally, commercial bases such as lime, potash, and caustic soda were added to neutralize hydronium ion in HMF samples, and the rates of HMF formation were compared at 45 degrees C.