الفهرس 
Abstract
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Abstract
Since honeybees (Apis mellifera L.) pollinate more than 90% of the species of flowering plants in the world, their function as pollinators is crucial. Due to the enormous output of honey, royal jelly, beeswax, pollen, venom from bees, and propolis that is utilized in the culinary, cosmetics, and pharmaceutical industries, honeybees are one of the most significant insect species. In the past ten years, beekeepers, and scientists all around the world have become increasingly concerned about the rising number of honeybee colony losses. To understand this phenomenon, numerous research and collaboration programmers have been launched. The usage of agrochemicals is thought to have been a major contributing element to this collapse, along with parasites, diseases, and environmental variables. Synthetic pesticides have been used in agricultural production to manage weeds, dangerous insects, and phytopathogenic fungi, raising worries about potential adverse effects on beneficial insects. In addition to controlling the intended creatures, such pesticides may also impact honeybees when used on flowering plants, and herbicides may reduce biodiversity and the amount of feed plants in agricultural environments. Low levels of pesticide exposure often do not cause bees to die immediately, but they may have an impact on their capacity to obtain nectar, learn and remember where flowers are located, and navigate back to the swarm. Current strategies not only concentrate on colony failure but also on honeybee deterioration caused by exposure to such chemicals at sublethal levels. Pesticide residues in honey occur when bees search for food, visit crops that have been treated with various agro-chemicals or when beekeepers use chemicals to control bee pests or diseases. In order to assess any potential health risks and make sure that honey’s quality, whether as a food or a therapeutic, has not been compromised, numerous researchers have reported various pesticide residues in honey at varying concentrations. This confirms the need to continuously monitor the presence of pesticide residues in honey. Hence, investigations were made to study the following objectives:(1) In vivo, toxicological effects of certain pesticides on honeybee, Apis mellifera, (2) In vitro, effects of certain pesticides on royal glands, water content, total protein, lipides of honeybee. (3) effect of sublethal concentrations of certain pesticides on some enzyme activities of honeybee (4) Monitoring of certain pesticide residues in honey and related Health Risk Assessment in some Assuit regions.
Results were reported in accordance with the objectives outlined above as follows:
Chapter2. Toxicity of some Agro-Pesticides on Honeybee, Apis Melliferea L. (Hymenoptera: Apidae) under Laboratory Conditions
1. 1. Pesticides toxicity on honeybee workers after 24 hrs.:
The toxicity of the tested pesticides stated that, among all tested pesticides Emamectin benzoate recorded the most toxic compound with LC50 value 0.247 ppm and LC90 5.752 ppm and the toxicity index for both LC50 and LC90 was 100. On the other hand, glyphosate showed least toxicity level with LC50 6861.151 ppm and, LC90 28243.795 ppm; with toxicity index: 0.003 and 0.020; respectively.
1.2. Pesticides toxicity on honeybee workers after 48 hrs.:
Increasing hours of exposure to pesticides more than the first treatment (24 hrs.) stated that, the toxicity of emamectin benzoate still the highest one on honeybee workers after 48 hrs. and stayed on the same line of first treatment result with an acute toxicity effect with LC50 values 0.047 and LC90 0.302 ppm, and with toxicity index: 100 for both LC50 and LC90. Regarding the least toxic one, glyphosate is still in the same acute level of the previous treatment with LC50 value 3366.968 ppm and LC90 9033.695 ppm, with toxicity index: 0.0013 and 0.0033; respectively.
1.3. Pesticides toxicity on honeybee workers after 72 hrs.:
Data confirmed that Emamectin benzoate is the highest toxic insecticide among all tested groups during the three experimental exposure periods with LC50 value 0.020 and LC90 0.072 ppm: with toxicity index 100 for both LC50 and LC90. Certainly, glyphosate results demonstrated its lowest toxicity on honeybee workers in all treatments with LC50 2477.276, and LC90= 6203.485 ppm.
Chapter 3. Effect of Sublethal Concentrations of some Pesticides on Physiological characters of Honeybee Workers under Laboratory Conditions
2.1. Effect of exposure of pesticides on food consumption rate
Food consumption from sugar solution which treated and untreated with sublethal concentration of seven groups of pesticides was recorded daily in mL/bee. Natural mixed pollen dough was consumed mainly by honeybee workers during the first week of their nursing period. However, honeybees tended to consume larger quantities of sugar solution after the first week of adult life when they stopped taking pollen. In general, at the end of the exposure period (18 days), it appeared that the amount of sugar solution consumption was higher in untreated solution (control) than all bees exposed to sublethal dose from certain pesticides. At the same time, also the pollen consumption reduced in most treatments exposed to sublethal concentrations. The decreasing percentages ranged between 9.53 to 18.79%. A significant decrease in hoarding behavior for treated sugar solution was recorded in only five pesticides. The percentages of decreasing ranged between 15.15% to 27.15%. Insignificant less amount from treated sugar solution was recorded in two pesticides.
2.2. Effect of exposure of honeybee workers on oral sublethal concentrations on HPGs development.
Morphological evaluation of HPGs development were recorded in as a volume of HPGs acini. Data showed that when nursing bees were exposed orally for 7 days to sublethal concentrations of certain pesticides had a significant decrease in the volume of HPGs acini in all treatments. The reduction percentages ranged between 31.28 to 55.62%. The highest reduction of acinus volume was recorded when nursing bees orally treated with chlorpyrifos and imidacloprid pesticides.
2.3. Effect of sublethal concentration exposure on water content
The change in honeybee adult’s weight and their bodies water content after exposed to sublethal concentration during nursing period of honeybee until 18 days old are considered as criteria for studying honeybee nutrition. As shown in the water content of honeybee worker fed on untreated and treated sugar solution was calculated as a difference between wet and dry matter of honeybee adult (18 days-old). The water content of adult (18 days) was slightly increased in untreated against the treated bees. This result reflects that there is less mobilization in untreated bees (cont.) than other treated bees water content in adult bodies in all treatments was lesser than control (78.04) which reflecting. Maximum decreased in water content was observed with adult of honeybee worker fed on Lambada sublethal concept of insecticide. No significant differences were detected among control other treatments.
2.4. Effect of sublethal concentration exposure on protein content
Data shows the effect of addition sublethal concentrations of certain pesticides to sugar solution on protein content of honeybee adult during nursing period. Protein content decreased in all treatment in the adult after 18 days from emergence. The negative percentage ranged between -1.26 to -12.03%. Significant differences were recorded with the indoxacarb, lambada cyhalothrin, Glyphosate and Thiophanate methyl pesticides and control.
2.5. Effect of sublethal concentration exposure on fat content
The state of metabolism as food reservoir results at the end of nursing period in body of adult (18 days-old) was determined. Continuously, oral feeding with sugar solution contains sublethal concentration from certain pesticide to adult emergency until 18 day-olds. The fat content significantly increased after exposure by sublethal concentration from certain pesticides.
Chapter 4. Effects of certain pesticides at sublethal concentration on the activity of acetylcholinesterase and carboxylesterases on honeybees (Apis mellifera L.) under lab conditions
All treatments considerably reduced AChE activity compared to the control. The data demonstrates that lambada-cyhalothrine and thiophanate-methyl insecticide have greatly promoted the carboxylesterase using phenyl and α-naphthyl acetate as substates and P-NO2 phenyl acetate as opposed to the untreated bees, imidacloprid, indoxacarb, and emamectin benzoate significantly reduced the enzyme activity.
Chapter 5. Monitoring of Certain Pesticide Residues in Honey and Related Health Risk Assessment in some Assuit Regions
3.1. Pesticide residues in honey:
Data shows that the all-tested pesticides when using gas chromatographic tandem mass spectrometry (GC- MSMS) were not detected any pesticide in honey samples were collected from Assiut governorate in the present study. While about 13 % of honey samples were contaminated with one pesticide, only 83 % were not contaminated with any pesticide. The results of honey samples showed that acetamiprid was detected in samples collected from El-Badari, Abnob and sudfaa with concentrations of 0.02 µg / kg when used liquid chromatography tandem mass spectrometry (LC- MS/MS).
3.2. Pesticides residues in beeswax:
Data show a total of eleven beeswax samples when using gas chromatographic tandem mass spectrometry (GC- MSMS) and liquid chromatography tandem mass spectrometry (LC- MS/MS) not detected any pesticide in samples collected from Assiut governorate in the present study.
3.3. Pesticides residues in pollen:
The result show, no pesticides were found in any of the eleven pollen samples used in the current investigation when they were analyzed using gas chromatography tandem mass spectrometry (GC- MSMS) and liquid chromatography tandem mass spectrometry (LC- MS/MS).
3.4. Determination of acetamiprid insecticide residue in honey samples:
Data shows the acetamiprid residues were detected when using liquid chromatography tandem mass spectrometry (LC- MS/MS). The results of honey samples showed that acetamiprid concentration was revealed in samples collected from El-Badari (0.02 µg / kg), Abnob (0.02 µg / kg) and sudfaa with concentrations of 0.02 µg / kg was discovered to have fallen short of the MRL set by the European Union Database of Insecticides.
3.5. Determination of the health risk levels of acetamiprid:
The hazard index values indicate that all pesticide residual intakes are still significantly below the allowable limit. In this study, dietary pesticide intakes were computed while accounting for exposures from honey.