This experiment assessed the efficacy of rotenone and oxalic acid (OA) in an aqueous sugar solution in controlling the honeybee mite
Varroa destructor. Colonies were populated with mite-infested ...brood combs and worker bees. Three rotenone or OA treatments administered during the period with capped brood on 31 July, 14 and 18 August resulted in an average efficacy of 24.10%. In untreated colonies mite mortality averaged 5.40%. No significant differences (
P>0.05) were found between the rotenone and OA treatments. Three OA treatments administered on 9, 12 and 18 September resulted in a 77.93% mite mortality. An increase in mite drop (
P<0.05) was observed at 2 and 4 days after each treatment. OA applications in broodless colonies resulted in significantly (
P<0.001) higher mite mortality rates (98.65% average) than the three treatments of rotenone or OA in colonies with capped brood. The dynamics of mite mortality after each rotenone or OA treatment are discussed in this study.
The genetic structure of Apis mellifera carnica bee from Slovenia, collected from 269 localities of ten Slovenian districts, was assessed by mitochondrial and nuclear DNA analyses. The level of ...genetic variability within and among districts was low. All of the samples were fixed for one newly found mtDNA haplotype of the C phylogenetic lineage, designated as C2C. A low level of variability was observed for all microsatellite loci, showing a very homogenous structure of the Carniolan bee population. Samples collected in the neighbouring district of Croatia expressed very similar results. On the other hand, high genetic differentiation was observed in comparison with A. m. macedonica population. Present study represents the first attempt to characterise indigenous honeybee populations in Slovenia using molecular methods. Furthermore, it indicates that the Carniolan bee from Slovenia still represents an indigenous gene pool within A. m. carnica.
Morphometrical investigations were done on 732 honeybee workers from 44 colonies in the apiary of the Agricultural Institute of Slovenia. Fore- and hind-wing area, cubital index, length of hairs on ...tergite 5, side surfaces of tibia, femur and metatarsus, and the length of tibial hairs on the prepared hind legs were measured. The total side surfaces of hind-leg and wings were calculated. Investigated characteristics of bees were divided into 2 groups: the first group included hind-leg and wing sizes while the second included hairs and index characteristics. The characteristics from the first group showed more expressed phenotypic and genetic correlation than the characteristics from the second group. All estimated heritabilities were large and significant. In an artificial selection of described properties of bees the selected traits are more or less successfully changed, the unselected characteristics are always a compromise between genetic relationships to the selected trait, and selection due to environment.
Total amount of 4.355 records of honeybee colonies production characteristics was estimated on the 251 bee yards in Slovenia from 1993 to 2001. Queens were produced on 29 queen producing yards. The ...average lsmeans of honey yields increased by 0,41 kg a year. The swarming behaviour and the defensive behaviour of bees increased as well by - 0,091 points, and –0,038 points respectively. According to the last two years records, the honey yields of bee colonies were significantly influenced by the drone gene pool at queen production yards. The swarming behaviour was in contrary more influenced by the queen mothers on queen production yards. The defensive behaviour of bee colonies and the daily varroa mite fall were not significantly influenced by parents.
The hoarding behavior of groups of 50 honeybee workers in test cages was measured under balanced circumstances in an incubator at 28 degree C and 60-70% relative humidity. The repeatability of the ...results was estimated using the maximum likelihood method and varied according to the series. This made the test less reliable. Both methods were tested on syrup hoarded from 1-12 using 6-9-day-old bees. The methods gave results with a changeable level of repeatability. Therefore, testing hoarding behavior of worker bee groups cannot replace the monitoring of bee colonies throughout the whole season.
Mitochondrial DNA from 62 samples of Apis mellifera carnica and A m ligustica collected from within areas of endemism and an area of known introgression was extracted and digested with the ...restriction enzymes AccI, BclI, BglII, EcoRI and XbaI. Digestion with XbaI revealed a polymorphism with an asymmetrical distribution between the subspecies. This polymorphism occurs primarily in Austrian and Slovenian A m carnica and may be useful for studying introgression between this race and A m ligustica .
The influence of worker bee source for populating mating nuclei on the degree of infection with Nosema apis Zander spores was examined. One-day-old bees were obtained by inserting brood combs into an ...incubator at 34-35 degree C. Older worker bees were taken from the same donor colony. Bees from the incubator were free from Nosema infection. The average infection level in donor colonies was 26.5% infected bees. At the end of the experiments the Nosema infection level was significantly lower in mating nuclei which were populated with bees from the incubator. Out of 23 examined queens, 2 were Nosema -infected; both came from mating nuclei with young worker bees. No statistically significant difference in Nosema disease level was found between the 2 sizes of nuclei used, populated with 1/3 l and 3/4 l bees respectively.
Total amount of 4.355 records of honeybee colonies production characteristics was estimated on the 251 bee yards in Slovenia from 1993 to 2001. Queens were produced on 29 queen producing yards. The ...average lsmeans of honey yields increased by 0,41 kg a year. The swarming behaviour and the defensive behaviour of bees increased as well by - 0,091 points, and -0,038 points respectively. According to the last two years records, the honey yields of bee colonies were significantly influenced by the drone gene pool at queen production yards. The swarming behaviour was in contrary more influenced by the queen mothers on queen production yards. The defensive behaviour of bee colonies and the daily varroa mite fall were not significantly influenced by parents.
Total amount of 4.355 records of honeybee colonies production characteristics was estimated on the 251 bee
yards in Slovenia from 1993 to 2001. Queens were produced on 29 queen producing yards. The ...average
lsmeans of honey yields increased by 0,41 kg a year. The swarming behaviour and the defensive behaviour
of bees increased as well by - 0,091 points, and –0,038 points respectively. According to the last two years
records, the honey yields of bee colonies were significantly influenced by the drone gene pool at queen
production yards. The swarming behaviour was in contrary more influenced by the queen mothers on queen
production yards. The defensive behaviour of bee colonies and the daily varroa mite fall were not
significantly influenced by parents.
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