Comb Cell Research Articles

High variation of worker cell and morphology between two adjacent populations of honey bee, Apis cerana (Hymenoptera, Apidae)

Honey bee population inhabiting among different geographic regions often exhibit distinctive traits and phenotypes as a means of enhancing their adaptation to local environmental conditions. Morphological difference of worker was used to reflect the honey bee population locality adaptation and as one of the important markers of species evolution. Here, four comb cell and seven morphology characters of honey bee Apis cerana from two adjacent populations of Yunnan Province were measured to explore the effect of local adaptation on worker comb cell and morphology. Results showed that the characters of worker comb cell and morphology was significant difference between samples from these two local populations of A. cerana. It was separated into two groups which corresponding into the general A. cerana geographic population of Yungui Plateau and South Yunnan base on worker comb cell and morphology character. The worker comb cell size and morphology of A. cerana from Qujing were found to be significantly larger than those from Cangyuan. The indices that showed the most significantly different between populations were cell depth and right forewing length. Moreover, a strong positive correlation was observed between the cell diagonal diameter and the right forewing length, with a correlation coefficient 0.575. In conclusion, honey bee A. cerana population appear high variation in comb cell and morphology to adapt the locality environment. The forewing length of worker was the most significant variation indices between geographic populations, and could be as an indicator of worker cell and morphology among different A. cerana geographic populations.

The Effect of Comb Cell Size on the Development of Apis mellifera Drones.

The growth and development of honeybees are influenced by many factors, one of which is the cell size of the brood comb. Larger worker bees can be obtained by being raised in bigger cells. However, whether cell size has the same effect on drone development is still unknown. Here, using 3D-printed foundations, we observed the development of drones kept in comb cells of different sizes from the late larval stage through eclosion. The results showed that drones in larger cell-size combs had heavier body weights, longer body lengths, and larger head widths, thorax widths, and abdomen widths compared to those in smaller cell-size combs. Furthermore, regardless of developmental stages, the drones' body weights increased linearly with the comb's cell size. However, the other morphological changes of drones in different developmental stages were out of proportion to the cell-size changes, resulting in smaller cells with a higher fill factor (thorax width/cell width). Our findings confirm that comb cell size affects the development of honeybees; drones become bigger when raised in large cells.

The Identification of Bee Comb Cell Contents Using Semiconductor Gas Sensors.

Beekeeping is an extremely difficult field of agriculture. It requires efficient management of the bee nest so that the bee colony can develop efficiently and produce as much honey and other bee products as possible. The beekeeper, therefore, must constantly monitor the contents of the bee comb. At the University of Warmia and Mazury in Olsztyn, research is being carried out to develop methods for efficient management of the apiary. One of our research goals was to test whether a gas detector (MCA-8) based on six semiconductor sensors-TGS823, TGS826, TGS832, TGS2600, TGS2602, and TGS2603 from the company FIGARO-is able to recognize the contents of bee comb cells. For this purpose, polystyrene and wooden test chambers were created, in which fragments of bee comb with different contents were placed. Gas samples were analyzed from an empty comb, a comb with sealed brood, a comb with open brood, a comb with carbohydrate food in the form of sugar syrup, and a comb with bee bread. In addition, a sample of gas from an empty chamber was tested. The results in two variants were analyzed: (1) Variant 1, the value of 270 s of sensor readings from the sample measurement (exposure phase), and (2) Variant 2, the value of 270 s of sensor readings from the sample measurement (measurement phase) with baseline correction by subtracting the last 600 s of surrounding air measurements (flushing phase). A five-time cross-validation 2 (5xCV2) test and the Monte Carlo cross-validation 25 (trained and tested 25 times) were performed. Fourteen classifiers were tested. The naive Bayes classifier (NB) proved to be the most effective method for distinguishing individual classes from others. The MCA-8 device brilliantly differentiates an empty comb from a comb with contents. It differentiates better between an empty comb and a comb with brood, with results of more than 83%. Lower class accuracy was obtained when distinguishing an empty comb from a comb with food and a comb with bee bread, with results of less than 73%. The matrix of six TGS sensors in the device shows promising versatility in distinguishing between various types of brood and food found in bee comb cells. This capability, though still developing, positions the MCA-8 device as a potentially invaluable tool for enhancing the efficiency and effectiveness of beekeepers in the future.

Comparison of the comb cell structure of Apis dorsata (Hymenoptera: Apidae) in two areas of China

The comb cell structure of Apis dorsata in different ecoregions is rarely reported. This study compared the differences in the comb cell structure of Apis dorsata from Menghai of Yunnan Province and Chengmai of Hainan Province, China. Accordingly, parameters such as brood comb thickness, the width of ten consecutive brood cells, cell diameter, depth, inclination angle, and the side length of the cell mouth were measured. The results showed that within the same area, the widths of ten consecutive cells and single-cell diameter in the 0° direction were significantly bigger than that in the 60° and 120° directions, however, there was no significant difference for the same between the 60° and 120° directions. The average width of ten consecutive cells and the single-cell diameter showed significant differences between the two areas. These were significantly bigger in Menghai than in Chengmai. The average thickness of the brood comb, cell depth, and side length of the cell mouth were also significantly higher in Menghai than in Chengmai, however, the cell inclination angle showed no regional difference. These differences in the comb cell structure of Apis dorsata may be due to the difference in the ecological environment of the two areas. This study revealed the structural characteristics of the comb cells of Apis dorsata in different areas of China, increasing our biological knowledge of this bee species.

Workers of Apis mellifera Reared in Small-Cell Combs Show Higher Activity of the Proteolytic System in Hemolymph than Workers Reared in Standard-Cell Combs in Laboratory Cage Tests.

The aim of the study was to compare the activities of proteases and their inhibitors in the hemolymph of honeybee workers reared in small-cell combs (SMC) and standard-cell combs (STC) in laboratory cage tests. The analyses conducted in laboratory conditions facilitated assessment of the impact of the comb cell width (small vs. standard) along with eliminating the influence of many environmental factors on the results. The width of the comb cells in which the workers were reared had a significant effect on the protein concentrations and proteolytic system activities in the hemolymph. Irrespective of the age of the workers, higher protein concentrations were found in the hemolymph of the SMC workers. In turn, the activities of proteases and their inhibitors in the hemolymph of 1-day-old bees were higher in the STC workers. In older bees, aged 7-21 days, activity was higher in the SMC workers. The role of the considerable cell width variability in natural combs that were built without the use of an artificially produced wax foundation is worth investigating. It is highly probable that the impact of the comb cell width on the features of workers reared in these combs modifies the age polyethism in the worker caste as well. The investigation results of one-season studies of honeybees could be seriously affected by random factors. To reduce the risk of these effects, it is advisable to continue experiments over a few consecutive years.

Effect of Rearing in Small-Cell Combs on Activities of Catalase and Superoxide Dismutase and Total Antioxidant Capacity in the Hemolymph of Apis mellifera Workers

Honeybee nests constructed without man-made wax foundation have significantly more variability of cell widths/sizes than those in commercially-kept colonies. The effects of this natural variability in comb cell widths on individual and colony traits have not been explained to date. The investigation of this problem can lead to new findings about the biology, physiology, and possibly, the evolution of the honeybee. The aim of the study was to compare the catalase and superoxide dismutase activities and the total antioxidant capacity levels in the hemolymph of honeybee workers reared in small-cell combs and standard-cell combs in colonies kept simultaneously on standard- and small-cell combs. The ratio of the small-cell combs to the standard-cell combs in the nest was 1:1. The workers reared in small-cell combs were characterized by higher antioxidant activities in the hemolymph than those reared in standard-cell combs. Consequently, their hemolymph had a greater antioxidant capacity, which indicates that they may be better predisposed to be foragers than workers reared in standard-cell combs. To describe the physiological differences between worker bees reared in small- and standard-cell combs in the same colony, the role of the considerable variation in the cell width in natural combs built without the use of artificially produced wax foundation is worth elucidating. The comparison of the apiary and cage experiments indicated that changes in antioxidant activities predominantly result from worker activities, especially those requiring the intensification of metabolism, rather than the age of the worker bees. To reduce the impact on the results of random environmental factors potentially present in one-season studies of honeybee research, investigations should preferably be carried out over a few consecutive years.

Comb Cell Structure and Morphological Characteristics of the Chinese Honey Bee, Apis cerana cerana (Hymenoptera: Apidae), Under Successive Generations.

This study investigated the changes in comb cell structure and external morphological characteristics of the Chinese honey bee under ten successive generations to determine the optimal time to replace the old combs. Accordingly, ten Chinese honey bee experimental colonies were established, and natural combs were constructed for continuous rearing of workers for 1-10 generations. The brood comb thickness, brood cell structure, birth weight, and morphological characteristics of workers were determined. Pearson correlation analyses between brood comb structure and morphological characteristics of workers were carried out. The results revealed that under ten successive generations, the color of the brood comb deepens from white or light yellow to brown and finally to black. Also, concerning the brood cell shape, the cell base changes from the three-rhomboid structure to the hemisphere, and the cell body changes from the hexagonal prism structure to the cylinder. The brood cell depth increases with an increase in brood comb thickness. The cell volume reduces with the hexagonal cell's decreasing inner circumference side length, and diameter. A smaller cell volume leads to a decrease in the birth weight and body size of the worker, in addition, the Chinese honey bee has gnawed off the comb cells that have been cultivated for eight generations. This study suggests that the combs of Chinese honey bees should be replaced after eight generations to improve colony strength and production performance.

Does Dry or Fresh Bee Bread Contain Clinically Significant, and Antimicrobial Agents Resistant Microorganisms?

Bee pollen, which is filled into the cells of the honeycomb by honeybees to use in nutrition, is enriched with digestive enzymes and organic acids from honey and salivary gland secretions of honeybees. Lactic acid fermentation takes place in the comb cell under anaerobic conditions and bee bread is formed. We have limited knowledge about which bacteria and yeasts are involved in fermentation process. Samples of bee bread collected from 8 different beehives in the same apiary and samples of bee bread that were dried for 3 months and stored in the deep freezer were analyzed microbiologically. The 34 strains were isolated from fresh perga samples. No microorganism was growth in dried perga samples. The isolated strains were identified by conventional and MALDI-TOF MS methods. The 34 strains were identified as Aspergillus spp. (12), Rhizopus oryzae (6), Mucor circinelloides (1), Bipolaris (2), Trichoderma (3), Paecilomyces variotii (1), Penicillium chrysogenum (1), Kodamaea ohmeri (1), Bacillus altitudinis/pumilus (3), Bacillus licheniformis (1), B. megaterium (1), Micrococcus luteus (1) and Serratia marcescens (1). MICs values of itraconazole, voriconazole, anidulafungin and caspofungin for Mucor and Rhizopus strains had high (≥32 μg/ml) except amphotericinB, posaconazole. MICs values of drugs for Aspergillus strains (n:9/12) were low (1 μg/ml). Trichoderma strains had low MIC values (≤0.50 μg/ml) for other drugs except itraconazole. P.chrysogenum was found to have low MIC value (≤0.25 μg/ml) for posaconazole, anidulafungin, caspofungin. Bipolaris, P.variotii and K.ohmeri was had low MIC values to all antifungals. 
 The determination of the microbiological load in bee bread samples analyzed as soon as they are collected from the hive allows us to discuss the beneficial and harmful aspects of these microorganisms, while the absence of microbial load in bee bread samples stored under appropriate conditions is striking.

Parasitism and brood mortality in Alfalfa Leafcutting Bee (<i>Megachile rotundata</i> (Fabricius)), nesting in vacated comb cells of European Paper Wasp (<i>Polistes dominula</i> (Christ))

Social paper wasps (Hymenoptera: Vespidae) construct comb nests of tens to hundreds of brood cells that are abandoned each year before winter. The nests are positioned where they are protected from inclement weather and may remain intact for several years. Here, I detail observations of nests provisioned by the non-native, solitary Alfalfa Leafcutting Bee (Megachile rotundata (Fabricius, 1787); Hymenoptera: Megachilidae) in individual brood cells in vacated combs of the invasive, social European Paper Wasp (Polistes dominula (Christ, 1791)) on a green roof in Toronto, Ontario. A total of 12 paper wasp combs were dissected and 280 M. rotundata nests (one per wasp comb cell) were recovered; 22 nests were provisioned in 2013 consisting of 32 individual M. rotundata brood cells. Parasitism by Melittobia and Monodontomerus wasps accounted for 46.9% of M. rotundata mortality in the cells in 2013; mortality from all causes, including parasitism, was 78.1%. In contrast, total mortality of M. rotundata in brood cells provisioned in a human-made bee nest box on the same roof in 2013 was 4.2% and there was no parasitism. Mortality by parasitism and total brood mortality in 391 brood cells provisioned in 41 nests in the bee nest box in 2011–2013 were 2.0% and 21.2%, respectively. Therefore, the use of vacated paper wasp comb cells resulted in an overall >20-fold increase in parasitism and >3-fold increase in brood mortality over that observed in the bee nest box when all years are combined.

Effect of Comb Cell Width on the Activity of the Proteolytic System in the Hemolymph of Apis mellifera Workers.

Simple SummaryHoneybees are threatened by many biotic factors, e.g., microbes and parasites such as Nosema spp. and Varroa mites, or predators, as well as environmental factors such as weather conditions, pesticides, or food contaminants. Honeybee colonies have behavioral defense mechanisms against pathogens resulting from their social lifestyle. Moreover, these insects have innate immune barriers. One of the immune defense elements is the proteolytic system consisting of proteases and their inhibitors in the hemolymph (insect blood) and on the body surface. The proteolytic system is activated by both external and internal environmental factors. An important element of the nest environment is the comb. In feral bee colony nests, the bee comb cell size varies in width. In turn, bee colonies in Europe tend to be kept only on standard- (cell width approx. 5.50 mm) or small-cell (cell width approx. 4.90 mm) combs. We assessed the proteolytic system activity in the hemolymph of workers reared in a small-cell comb and a standard-cell comb in colonies kept simultaneously on standard- and small-cell combs. Simultaneous keeping of a colony on standard- and small-cell combs is a novel approach to the use of small-cell combs in beekeeping. The width of comb cells (small or standard) where workers were reared had a significant effect on the protein concentrations and the activities of proteases and protease inhibitors in hemolymph of workers. The protein concentrations in 1-day-old workers were higher in bees reared in small-cell combs than in those reared in standard-cell combs. The opposite was found in the groups of older bees (aged 7, 14 and 21 d). Moreover, the activities of proteases and their inhibitors in 1-day-old workers were always higher in bees reared in standard-cell combs, whereas opposite results were usually obtained in the group of the older workers. The differences between workers reared in the small-cell combs and those from the standard-cell combs may be associated with their different tasks. Workers reared in small-cell combs probably work outside the nest as foragers, whereas those reared in standard-cell combs work in the nest. However, this assumption requires confirmation.This study is a continuation of the innovative research of the impact of rearing of bee colonies simultaneously on standard- and small-cell combs on the traits of worker bees and bee colonies. Its aim was to compare the activities of proteases and their inhibitors in the hemolymph of workers reared in a small-cell comb (SMC) and a standard-cell comb (STC) in colonies kept simultaneously on standard- and small-cell combs. The width of comb cells in which workers are reared has a significant effect on the protein concentration and the proteolytic system in the hemolymph, which is reflected in the activities of proteases and their inhibitors. The protein concentrations in the 1-day-old workers were always higher (p ≤ 0.05) in the SMC than STC workers. The opposite was found in the older bee workers (aged 7, 14 and 21 d). The activities of proteases and their inhibitors in the 1-day-old workers were always higher (usually significantly at p ≤ 0.05) in STC than SMC workers, and opposite results were observed in the groups of the older workers (aged 7, 14 and 21 d). The differences between the workers from small-cell combs and those reared in standard-cell combs may be related to their different tasks. Workers reared in small-cell combs probably work as foragers outside the nest, whereas bees reared in standard-cell combs work in the nest. This hypothesis requires confirmation. To reduce the impact of accidental determinants on the results of single-season research on honeybees, it is advisable that such investigations should be conducted for several consecutive years.

Effect of comb age on cell measurements and worker body size.

The honey bees (Apis mellifera L.) mainly use beeswax (comb) for brood rearing and food storage. Changes in the color and cell dimensions occur due to repeated food storage and brood rearing in the comb. The study aimed to determine the changes in comb cell measurements and worker body sizes in relation to comb age. For this purpose, the cell measurements of combs at age zero (wax foundation), 1, 2, 3, 4, 5, and 6 years and the body size of workers reared in them were estimated. The weight of the comb, the height of the cell base, and the weight of accumulated substances in the cell significantly increased with time. Comb age had negative effects on the cell diameter, cell depth, cell volume, cell honey or pollen capacity, and newly emerged worker body weight. Significant negative correlations were observed between the accumulated substances in a cell and the cell diameter, cell depth, and cell size, while significant positive correlations were observed among the cell volume, cell diameter, cell depth, cell honey capacity, cell pollen capacity, and worker body weight. It can be concluded that the dimensions of the comb cells and worker body size changed with the age of the comb. The obtained results recommend beekeepers to replace combs aged more than 3 years with a new comb to allow large workers to gather more nectar and pollen, rear a larger brood, and store more honey.

Possibility to change the body size in worker bees by a combination of small-cell and standard-cell combs in the same nest

The aim of the study was to investigate the impact of the combination of the colony type (kept on small-cell or standard-cell combs) and the width of worker comb cells (small-cell or standard-cell combs) on the body weight and morphometric traits of worker bees. The values of morphometric parameters of worker bees changed within a substantially lower range than the width of their rearing cells. This indicates that the worker body size is relatively constant, and manipulation with the cell width is not a good method for modeling the body size of workers. The reduction in the thorax weight was proportional to the decrease in the comb cell width, and this part of the body proved to be most susceptible to weight reduction caused by the use of small-cell combs. The rearing of workers in small-cell combs in the colony kept on standard-cell combs resulted in an increase in the value of the fill factor (thorax width to cell width ratio). The relatively constant body size of workers in combination with the use of small-cell combs resulting in an increase in the fill factor may be one of the determinants of increased resistance of the insects to Varroa destructor. The values of the morphometric traits commonly used for identification of honeybee subspecies, i.e., the length of the fore wing, the sum of the widths of 3rd and 4thth tergites, and the proboscis length, were inconsiderably altered vs. the changes in the comb cell width, which confirms their high suitability for identification of honeybee subspecies.

Miniaturized multiresidue method for determination of 267 pesticides, their metabolites and polychlorinated biphenyls in low mass beebread samples by liquid and gas chromatography coupled with tandem mass spectrometry

Current work presents developed and validated miniaturized method for residue analysis of 261 pesticides and their metabolites as well as 6 congeners of non-dioxin like polychlorinated biphenyls (ndl-PCB) in a very low mass beebread sample. Sample preparation is based on modified QuEChERS protocol with all steps miniaturized to enable multiresidue analysis of sample with extremely low weight. Sample of beebread (0.3 g) was extracted with 1 mL of acetonitrile containing 5% formic acid and ammonium formate salt were added, then extract was subjected to clean-up by freezing and two-step dispersive solid phase extraction (dSPE) with a Supel QuE Verde sorbents (Supelclean ENVI-Carb Y; Supelclean PSA; Z-Sep+; magnesium sulfate). After 1st step dSPE a portion of extract was analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) for 200 pesticide residues. Remaining extract was subjected to 2nd step dSPE clean-up by another Supel QuE Verde and then after concentration and solvent exchange it was analyzed by gas chromatography tandem mass spectrometry (GC-MS/MS) for another 61 pesticide and 6 ndl-PCB residues. Method enables determination of residues of 101 insecticides, 72 herbicides, 67 fungicides, 10 acaricides, 6 growth regulators, 5 veterinary drugs and 6 ndl-PCB's. Particular attention was paid to the pesticides being active substances of plant protection products recommended for the protection of winter oilseed rape and apple orchards which during their blooming periods are one of the most attractive sources of food for pollinators and could serve as representatives of other economically important crops. Method was validated according to the Guidance document SANTE/12682/2019 at six concentration levels from 0.001 to 0.5 mg kg−1. The analysis of beebread samples spiked at the level of 0.01 mg kg−1showed mean recovery (trueness) value of about 98% and RSDr (precision) below 20%. The small weight of the sample did not adversely affect the limits of quantification and 75% of analytes could be quantified at least at concentration of 0.005 mg kg−1. Developed mini-method was tested in the analysis of beebread samples, each extracted from individual cell of honeycomb. It is the first time when analyses at single comb cell level were possible.

Evaluating and Comparing the Natural Cell Structure and Dimensions of Honey Bee Comb Cells of Chinese Bee, Apis cerana cerana (Hymenoptera: Apidae) and Italian Bee, Apis mellifera ligustica (Hymenoptera: Apidae)

The hexagonal structure of the honey bee comb cell has been the source of many studies attempting to understand its structure and function. In the storage area of the comb, only honey is stored and no brood is reared. We predicted that honey bees may construct different hexagonal cells for brood rearing and honey storage. We used quantitative analyses to evaluate the structure and function of the natural comb cell in the Chinese bee, Apis cerana cerana and the Italian bee, A. mellifera ligustica. We made cell molds using a crystal glue solution and measured the structure and inclination of cells. We found that the comb cells of A. c. cerana had both upward-sloping and downward-sloping cells; while the A. m. ligustica cells all tilted upwards. Interestingly, the cells did not conform to the regular hexagonal prism structure and showed irregular diameter sizes. In both species, comb cells also were differentiated into worker, drone and honey cells, differing in their diameter and depth. This study revealed unique differences in the structure and function of comb cells and showed that honey bees design their cells with precise engineering to increase storage capacity, and to create adequate growing room for their brood.

Investigating the Natural Bee Space and Comb Cell Dimensions of an Ethiopian Honeybee Race (<i>Apis Mellifera Scutellata</i>) in Borana Zone, Southern Ethiopia

A study to determine bee space and comb cell dimensions for local honeybee race (Apis mellifera scutellata) was conducted in two districts of Borana zone, Oromia regional state, Southern part of Ethiopia during 2017. Data regarding bee space, worker bee comb cell dimensions, comb thickness and comb space were measured in traditional log hives using digital caliper. Comb length and comb width were measured and the number of worker bee cells per unit area were marked and counted from the combs. The collected data was fitted in GLM procedure of SAS version 9 to identify the effect of agro-ecology and comb type on the considered parameters. The race maintained an average 11.30±1.99mm bee space and 18.78±3.0mm comb thickness. The overall worker bee cell width and depth of the race were 4.65±0.30mm and 10.28±0.74mm respectively. It was observed that the race can construct a comb with an average of 44.80cm long and 20.51cm wide in their nest. The mean number of worker bee cells count per 100cm2 is 539.44 cells (ranging from 441-621). This finding shows variations in bee space (11.30mm), cell diameter (4.65mm) and cell depth measurements (10.28mm) from other similar studies in the other parts of the country. Based on the analyzed data, it is understood that ecological differences (climate, vegetation type, altitudes, etc.) between the midland and lowland has got significant variation in biological diversity of the honeybee races of the study area compared to the other zones of the region/ country. Thus, it is suggested that further study on these measurements is required as parameters for the honeybee geographical races of the zone and the surrounding areas to come to a reliable recommendation to use this specification in improved hive construction.

Factors restraining the population growth of Varroa destructor in Ethiopian honey bees (Apis mellifera simensis).

Worldwide, the ecto-parasitic mite Varroa destructor has been assigned as an important driver of honey bee (Apis mellifera) colony losses. Unlike the subspecies of European origin, the honey bees in some African countries such as Uganda and Ethiopia may not be as threatened or suffer less from mite-infestations. However, only little is known about the factors or traits that enable them to co-exist with the mite without beekeepers’ intervention. Hence, this study was designed to investigate these factors or traits that limit the Varroa mite population in Ethiopian honey bees (Apis mellifera simensis). The study was conducted in the primary honey producing region of Ethiopia, i.e. Tigray. Mite infestation levels were shown to be lower in traditional hives (when compared to framed hives) and when colonies were started up from swarm catching (when compared to colony splitting). However, the influence of the comb cell size on mite infestation was not observed. With respect to the bee biology, the hygienic behavior was shown to be high (pin-test: 92.2% removal in 24 hours) and was negatively correlated with phoretic mite counts (Pearson; r = -0.79; P < 0.01) and mite infestation levels in brood (Pearson; r = -0.46; P < 0.001). Efforts to estimate the Varroa mite reproductive capacity were seriously hampered by an extremely low brood infestation level. From the 133 founder mites found (in 6727 capped brood cells) only 18.80% were capable of producing a reproductive progeny. Failure to produce adult male progeny was unexpectedly high (79.70%). We have suggested a few adaptations to the test protocols allowing to estimate the protective traits of honey bee colonies under very low Varroa pressure. Apart from that, this study demonstrates that the honey bees from Ethiopia are suitable targets to further decipher the genetic predisposition of resistance against V. destructor. It is still unclear to what extent simensis differs from the more common scutellata subspecies.

English

A study was conducted at Assosa and Mao-komo districts of Benishangul-gumuz regional state, western Ethiopia, aiming to determine the bee spacing and cell dimensions of honeybee race Apis mellifera scutellata. The measurement of bee spacing and cell dimensions were taken from 20 traditional hives at each agro-ecology. Assosa and Mao-komo districts were purposively selected to represent mid-altitude and highland agro-ecologies respectively. Data collected were analyzed in descriptive statistics, t-test, correlation and General Linear Model (GLM) procedures using statistical package for social sciences (SPSS) computer software. The present results revealed that bee space in naturally built combs of A. mellifera scutellata honeybee race in highland areas was significantly higher (P &lt; 0.001) than that of mid-altitude areas. Cell depths and comb thickness were significantly different (P &lt; 0.001) between the agro-ecologies. Larger cell depth and comb thickness were recorded in combs from mid-altitude than highland areas. On the contrary, cell diameter of naturally built combs in mid-altitude was significantly lower (P &lt; 0.001) than cell diameter in highland areas. Type of comb did not affect the bee space, comb thickness or cell dimensions. Dimensions of traditional hives were not different between the two agro-ecologies except hive length. Traditional hives in highland areas were significantly longer (P &lt; 0.05) than hives in mid-altitude areas. In conclusion, there were variations in bee space and comb cell dimensions within the same honeybees race in different agro-ecologies but this needs designing of new casting molds and box hives pertinent to the agro-ecologies. Key words: Benishangul-gumuz, cell diameter, comb thickness, hive dimension, natural combs.

Multi-Organ Teratogenesis Sequels of Bigger Size Particles Colloidal Silver in Primate Vertebrates

Back ground: In this most recent, update global arena for consumers products most of the daily applications of bigger silver nano particles (20 to 100 nano meter range) are effected as anti-viral and anti-parasitic agents in clinical medicine and diagnosis which is a positive feedback. However, the major negative feedback of bigger size silver nano particles on human, animal and primate vertebrate body is multisystem teratogenicity focuses. Material and methods: This study was designed to investigate teratogenic effects of bigger size nano silver which is poly vinyl pyrollidone coated and sodium borohydride stabilized. For this we injected its colloidal solution form in to pregnant female Swiss albino mice of different breeding colonies (10 from each group) in repeated oral gavages manner with nanosilver-71-1900.8 nano meter range at a dose of 14, 19 mg/kg/b.w./day with sham control treated by anionic double distilled water for 7-18 gestational days (12 days). Then dead animals are then anaesthetized and operated by ventral laparotomy on day 19. Fetuses were collected for open eye and hand lens morphological verification to locate various teratogenic anomalies. Result: We found multi system teratogenicity in treated group fetuses like Syndactyly, Oligodactyly, Polydactyl, meningo myelocele, closed type neural tube deformity, skeletal deformity like flat ribs, absence of bony segments or cleft, vertebral deformity like scoliosis, absence of long bones or its parts or mal developments or even mal fusion. We also found Central nervous system teratogenic effects like malformation of cerebrum, hippocampus and cerebellum. Histological teratogenic effects are observed in form of honey comb deformity and cell vacuolization in Central nervous system were significantly correlated with oxidative stress. Conclusion: Our findings suggest that bigger size silver nano particles induce an impairment of multi system and Central nervous system functions and teratogenic sequels by increasing oxidative stress and hampering nutrition in those body parts. The use of bigger silver nano particles for medical and diagnostic purposes henceforth requires careful consideration, particularly if it involves exposure of the human multi system and Central nervous system as it may evokes multi system teratogenicity in offspring’s where dose directly proportional to intensity.

Maturation and stratification of antibacterial activity and total phenolic content of bee bread in honey comb cells

Bee bread is processed pollen stored in honey comb. Pollen foragers unload pollen loads into the appropriate cells and hive bees further process it into bee bread. This results in a layered structure of the reserve, which is at the top covered with honey and a wax cap. The process of pollen collection and packing was monitored during chestnut (Castanea sativa Mill.) flowering and five frames of honey comb with stored bee bread were collected. We dissected the bee bread cells into bottom, middle and upper layers of bee bread and an additional top honey layer. Cells were sampled before covering with honey, after adding honey, and after aging of covered cells for four weeks. Samples were analyzed according to pollen type content, antibacterial activity and total phenolic content. Our results indicated that microbial activity and processing by honey bees were the major contributors to the antibacterial activity observed. Total phenolic content did not correlate with antibacterial activity and was the highest at the bottom of the honey comb cell. Honey bees establish a controlled microenvironment for bee bread fermentation and probably additionally stop microbe activity at the end of the process with feeding glands secretions.

Hexagonal comb cells of honeybees are not produced via a liquid equilibrium process

The nests of European honeybees (Apis mellifera) are organised into wax combs that contain many cells with a hexagonal structure. Many previous studies on comb-building behaviour have been made in order to understand how bees produce this geometrical structure; however, it still remains a mystery. Direct construction of hexagons by bees was suggested previously, while a recent hypothesis postulated the self-organised construction of hexagonal comb cell arrays; however, infrared and thermographic video observations of comb building in the present study failed to support the self-organisation hypothesis because bees were shown to be engaged in direct construction. Bees used their antennae, mandibles and legs in a regular sequence to manipulate the wax, while some bees supported their work by actively warming the wax. During the construction of hexagonal cells, the wax temperature was between 33.6 and 37.6°C. This is well below 40°C, i.e. the temperature at which wax is assumed to exist in the liquid equilibrium that is essential for self-organised building.