الفهرس يوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
The present investigation was initiated to evaluate certain biometrics, defensive behaviour, physiological and biochemical characters of the most common races of honeybee. Egyptian race and local Carniolan race and their hybrid were tested in Assiut region, in different seasons during the period from June 2006 till May 2008. The obtained results can be summarized as follows:
Part I: Biometrical studies of the Egyptian and local Carniolan races and their hybrid:
1- Mean areas of workers sealed brood:
The highest mean area of workers sealed brood was recorded by the local Carniolan race with an average of 334.5 sq.inch/colony. While the lowest area was recorded by the Egyptian race, with an average of 263.8 sq.inch/colony. The Carniolan hybrid exhibited medium value between parents, with a mean of 301.9 sq.inch/colony. The highest seasonal values were recorded during Autumn by the Carniolan hybrid wih a mean of 411.0 sq.inch/colony and during Summer by the local Carniolan race with an average of 437.8 sq.inch/colony. Variations between the monthly, seasonal and yearly mean areas of workers sealed brood were highly significant.
2- Mean areas of workers unsealed brood:
The workers unsealed brood (sq.inch) in tested colonies showed the same trend, as well as, the sealed brood. The descending order of the tested colonies was as follows: local Carniolan race followed by Carniolan hybrid, and Egyptian race. The highest seasonal values of workers unsealed brood were recorded during Autumn for the three tested colonies. Highly significant differences were recorded between all measurements during (2006-2008).
3 – Mean areas of drones sealed brood:
Similar results, as workers brood, were obtained during this work, whereas the tested colonies took the same ranking order. High variations were observed between the drones sealed brood areas from pure races, whereas the Carniolan race drones sealed brood was equal 2.73 more times, as compared with, Egyptian race. Spring contained the highest values of drones sealed brood areas with an average of 7.661 and 3.630 sq.inch/colony for the Carniolan and Egyptian races, respectively, while the Carniolan hybrid showed more value with a mean of 8.611 sq.inch/colony during Autumn. Seasonal values showed significant variations between the tested races and their hybrid.
4 – Adult population:
The highest adult population was recorded during Autumn with a mean of 17802, 16662, and 14085 adult/colony for local Carniolan race, Carniolan hybrid and Egyptian race, respectively. The lowest population was recorded during Spring with a mean of 12202, 11882 and 10057 adult/colony for the same tested races and their hybrid, respectively. Seasonal variations showed highly significant F value between the tested colonies. The same behaviour was recorded throughout the whole study period. Highly significant positive correlation was detected between adult population and sealed or unsealed workers brood.
5 – Mean numbers of queen cups:
For all of the tested colonies the highest mean numbers of queen cups was recorded during Spring, however, the lowest numbers were recorded during Summer with highly significant variations. The ranking order of the established queen cups throughout (2006-2008) was: 5.201, 3.636 and 3.297 queen cups/colony for the Carniolan race, Carniolan hybrid and Egyptian race, respectively, with non significant variations between the tested colonies. Highly significant and positive correlation was noticed between mean number of queen cups and mean sealed or unsealed workers brood.
6 – Mean numbers of unsealed queen cells:
Except for local Carniolan race which initiated a mean of one unsealed queen cell/colony during Spring, the other tested colonies established a mean of less than one unsealed queen cell/colony. The highest numbers of unsealed queen cells were recorded during Spring, however, the lowest numbers were recorded during Autumn with highly significant F value. During (2006-2008) the tested colonies took the same ranking order as the aforementioned measurements with an average of 0.394, 0.286 and 0.181 unsealed queen cells/colony for the local Carniolan race, Carniolan hybrid and Egyptian race, respectively.
7 – Mean numbers of sealed queen cells:
The highest mean numbers of the established sealed queen cells were recorded during Spring by the pure races (1.120 and 0.657 sealed queen cells/colony) for the Carniolan and Egyptian races, respectively. However, their hybrid established its highest seasonal sealed queen cells during Summer with an average of 0.398 sealed queen cells/colony. The tested colonies showed different ranking orders all over the study period. The Carniolan race established the highest number of sealed queen cells and followed by the Egyptian race, while the Carniolan hybrid established the lowest numbers with an average of 0.394, 0.206 and 0.195 sealed queen cells/colony for the abovementioned colonies, respectively. Significant differences were detected between races, months, seasons and their interactions.
8 – Mean numbers of out-going foragers;
Seasonal and yearly general mean numbers of out-going foragers during (2006-2008) showed highly significant differences between the tested races and their hybrid, whereas the amount of the Carniolan hybrid out-going foragers was highly than it’s parents. During the entire period of this work, Carniolan hybrid out-going foragers is equal 1.07 and 1.53 more times of the local Carniolan race and Egyptian race, respectively. Concerning the seasonal activity, Summer contained the highest numbers of out-going foragers with an average of 21.63, 18.18 and 13.80 out-going foragers/colony/min. day for the Carniolan hybrid, Carniolan and Egyptian races, respectively. However, Winter contained the lowest numbers for all of the tested colonies.
9 – Mean numbers of in-going foragers:
Similar behaviour was recorded between local Carniolan race and Carniolan hybrid, whereas similar numbers of in-going foragers were recorded during this work. On the other hand, the same differences between Carniolan bee and Egyptian bee is still recorded. General mean numbers of in-going foragers can be arranged in descending order as follows: Carniolan hybrid by 13.49, Carniolan race by 13.05 and Egyptian race by 9.08 in-going foragers/colony/min./day. Seasonal activities showed the same trend of out-going foragers, whereas, the highest in-going foragers were recorded during Summer, however, the lowest numbers were recorded during Winter for all of the tested colonies.
10- Mean numbers of in-going pollen collectors:
In-going pollen collectors showed the same behaviour of the in-going foragers, whereas the local Carniolan race and it’s hybrid showed high numbers than the Egyptian race with a mean of 2.87, 2.79 and 1.70 in-going pollen collectors/colony/min/day for the tested races and hybrid, respectively all over the study period. Summer season contained the highest in-going pollen collectors while Winter contained the lowest ones. Highly significant F value was detected between colonies, either during seasons, or throughout the whole study period. Highly significant positive correlation was detected between pollen collectors and each of sealed or unsealed workers brood, in-going or out-going foragers.
11 – Mean areas of stored pollen:
The highest general mean areas of stored pollen sq.inch/colony was recorded by local Carniolan race (164.4) which was equal 1.04 and 1.22 more times of areas established initiated by Carniolan hybrid and Egyptian race, respectively. Seasonal differential behaviour was noticed between the measurements and the aforementioned ones, whereas the highest areas of stored pollen were recorded during Autumn with an average of 230.8, 222.5 and 179.3 stored pollen sq.inch/colony for the Carniolan race, Carniolan hybrid and Egyptian race, respectively. However, the lowest areas were recorded during Spring for all of the studied colonies with a mean of 122.7, 121.3 and 106.1 sq./inch/colony for the abovementiond colonies, respectively. Highly significant differences were detected between the tested colonies during seasons and throughout the period of study.
12- Mean areas of stored honey:
Approximately equal areas of stored honey were recorded during this work by the local Carniolan race and Carniolan hybrid with an average of 353.8 and 341.5 sq.inch/colony, respectively. However, low areas of the stored honey was detected by the Egyptian race with a mean of 284.2 sq.inch/colony. Highly significant differences were detected between stored honey established by Carniolan and Egyptian bees. The highest seasonal mean areas of stored honey were recorded during Autumn with an average of 537.4, 508.4 and 464.8 sq.inch/colony for the abovementioned colonies, respectively. However, the lowest areas were recorded during Spring for all of the tested colonies with a mean of 237.3, 213.8 and 152.2 sq.inch/colony for the same colonies, respectively. It is of important to notice that Summer and Winter seasons contained similar quantities of the stored honey. Variations between all of the tested measurements showed highly significant F values.
13- Honey sac weight and pollen content:
During the entire period of this work, the sacs of Carniolan hybrid bees contained the highest weight in mg./sac (22.08 mg./sac.). It followed by the Carniolan race with a mean of 19.91 mg./sac. The lowest amount was recorded by the Egyptian race with an average of 9.09 mg./sac. The pollen content showed the same trend whereas the tested colonies can be arranged in descending order as follows: Carniolan hybrid by 31.74 followed by local Carniolan race by 23.61 and Egyptian race by 20.44 pollen content/sac. The highest seasonal honey sac weights were recorded during Summer with an average of 43.53, 42.47 and 34.42 mg./sac for the Carniolan hybrid, the local Carniolan race and Egyptian race, respectively. However, the lowest weights were recorded during Spring with a mean of 12.05, 12.24 and 20.00 mg./sac for the same colonies, respectively. The pollen content showed similar trend during seasons and throughout the whole period of study. Highly significant differences were detected between all of the tested measurements. Honey sac weight revealed highly significant positive correlation coefficient with out and in-going foragers and stored honey areas. Pollen contents revealed highly significant positive correlation coefficient with the mean numbers of out and in-going foragers and queen cups.
In general the tested colonies exhibited the same ranking orders in terms the brood rearing activities, whereas the local Carniolan race ranked the first and followed by the Carniolan hybrid, while the Egyptian race ranked the least. The local Carniolan race ranked the first in respect to out and in-going foragers, and followed by Carniolan hybrid and Egyptian race, respectively. The local Carniolan race also ranked the first in terms the in-going pollen foragers, the stored pollen and the stored honey. It is of important to notice that the Egyptian race ranked the least except for the sealed queen cells. Honeybee activities showed variable differences between seasons.
Part II: Behavioural defensive assay:
Defensive assay was build up on the hygienic behaviour or the ability of bees to remove the killed workers brood cells. On the other hand, the amount of fallen varroa, and others debris constituents, could be express about the grooming behaviour of the tested colonies. So the behavioural defensive assay was measured by the following measurements:
A – Estimation of hygienic behaviour:
Hygienic behaviour of the tested colonies was evaluated by the liquid nitrogen method (freezing methodology). The pure races removed approximately 69% of the killed workers brood cells after 24 h of freezing, however, their hybrid removed more than 86%. Similar quantities were removed by the parents after 48 h, however, more than 94% were removed by their progeny. After 72 h, the hygienic ability can be arranged in descending order as follows: Carniolan hybrid by 98%, Egyptian race by 97.43%, and local Carniolan race by 95.67%. Highly significant differences were recorded between hygienic values encountered by the tested races and their hybrid after freezing by 24 and 48 hours. However, non-significant F value was recorded after 72 hours.
B – Estimation of grooming behaviour and debris constituents:
The tested colonies showed differential ability in removing alive, dead and immature stages of varroa presented in honeybee hives. During this work the ability of the tested colonies in removing varroa can be arranged in descending order as follows: Carniolan race by 8.683, Carniolan hybrid by 7.853, and Egyptian race by 2.272 individuals/ colony. Therefore, grooming ability of Carniolan race is equal 1.12 and 3.82 more times as compared with the Carniolan hybrid and Egyptian race, respectively. Statistical analysis of the data revealed highly significant differences between races and their hybrid during months, seasons and all of their interactions.
Although, chalkbrood mummies were found in very small numbers, the local Carniolan race showed the highest ability in removing mummies and followed by Carniolan hybrid and Egyptian race with an average 1.075, 0.956 and 0.604 mummies/colony, respectively. Except for interactions between races, months and seasons which showed non significant F value, the remaining measurements showed highly significant differences.
Similar trend was recorded during the estimation of wax moth larvae presented in hive debris which showed highly significant differences between months and seasons during this work. The ability of the tested colonies in removing dead workers during this work, showed that Carniolan race removed 3.629 individuals/colony. The Carniolan hybrid and Egyptian race followed the Carniolan race with approximately equal numbers. Interactions between races, months and seasons showed non-significant differences, while the remaining measurements showed highly significant differences.
Part III: Physiological and biochemical studies:
A – Estimation of fresh and dry weight, water content, fat, protein, carbohydrate and elements in workers developmental stages:a-