Honeybees are exposed to pesticides direct or indirect ways through their food research trips.  Herein, this study examined the toxicity effects in the laboratory of seven tested pesticide insecticides from different pesticide groups. emamectin benzoate, imidacloprid, chlorpyrifos, indoxacarb, lambada cyhalothrine, glyphosate, and thiophanate-methyl on honeybee workers, Apis mellifera L. through different exposure periods of time at 24,48, and72 hours. The selected pesticides were ranked based on their toxicity from the most to least one as follows: emamectin benzoate, imidacloprid, chlorpyrifos, indoxacarb, and lambda cyhalothrine. Further, thiophanate-methyl and glyphosate were the lowest toxicity among selected pesticides. The highest toxic pesticide during the exposure period 24,48 and72 hrs was emamectin benzoate with LC₅₀ values(0.247,0.047 and 0.020 ppm) and with LC₉₀ values(5.752,0.302 and0.072ppm) respectively, and the least one was glyphosate with LC₅₀ values of (6861.151,3366.968 and 2477.267ppm) and LC₉₀ values of (28243.795, 9033.695 and 6203.485ppm) after 24, 48 and 72hr of exposure respectively. However, chlorpyrifos ranked the third toxic pesticide at 24 and 48 hrs of treatment with LC₅₀ values of 10.226and2.731ppm and with LC₉₀ values of (101.224 and 7.496ppm for24 and48 hrs, respectively). Whereas, after 72 hrs chlorpyrifos was recorded as the fourth toxic pesticide with LC₅₀2.086ppm and LC₉₀ 5.179ppm. Based on the toxicity index, results showed that the most to least toxic pesticides were arranged as follows: emamectin benzoate>imidacloprid >chlorpyrifos >indoxacarb>lambada cyhalothrine> thiophanate -methyl > glyphosate. These results demonstrated that pesticides are very toxic to honeybee workers and must avoid applying them when bees are most active such as during flowering periods.

Several pesticides may be directly responsible for reducing the performance and losses of honeybee colonies. The action of feeding a nursing honeybee worker sugar solution with a sublethal concentration of seven pesticide groups was evaluated under laboratory conditions. Various physiological characteristics of nursing honeybees including food consumption, development of food glands, body water content, and food reserves were considered as indications for the functional status of nursing honeybee workers. Food consumption rate was significantly reduced in all treatments except two treatments, chlorpyrifos, and thiophanate-methyl. Also, the development of hypopharyngeal glands was significantly reduced in all treatments the reduction ranged between   31 to 55.62%. At the end of the nursing period, the state of metabolism as a food reservoir was determined. A maximum decrease in adult water content was recorded under the effect of lambada-cyhalothrine pesticide treatment without any significant difference in all treatments. Otherwise, the protein content of adults significantly decreased in all treatments except with lambada-cyhalothrine pesticide treatment. Fat content significantly increased in all treatments. The present data reflects the negative effects of sublethal concentration after dietary oral application of certain pesticide groups during the nursing period of the honeybee.

Potato Tuber Moth, Phthorimaea operculella (Zeller), is one of the most dangerous pests infesting the potato crop in Egypt. Herein, five selected pesticides (Indoxacarb, sulfoxaflor, emamectin benzoate, thiamethoxam + chlorantraniliprole, and Bacillus thuringiensis) were evaluated on 1st instar larvae of P. operculella under laboratory conditions. As results, indoxacarb was the most potent pesticide through selected pesticides with LC50 value of 55.08 μg/ml after 24-h of exposure. After 72-h of treatment, emamectin benzoate was the most toxic pesticide among selected pesticides with LC50 value of 22.96 μg/ml. Further investigations are required to set these selected pesticides within integrated pest management (IPM) programs to control P. operculella in Egypt.

This study aimed to employ GC–MS to assess the chemical composition of MeOH leaf extracts of R. officinalis and A. indica and evaluate their insecticidal, antioxidant, and antibacterial activities. Twelve components, representing 98.61% and 100% of the total volatile compounds, were deduced from the extracted R. officinalis and A. indica, respectively, using this method. In R. officinalis extract, limonene is typically positioned as the main component (23.03%), while the main chemicals identified in A. indica extract were methyl (E)-octadec-13-enoate (23.20%) and (2R)-1,3,8-trimethyl-4-propyl-5-ethyl-2-(1-hydroxyethyl)-7-methoxycardonylethyl-6-methylenecarbonyl-porphyrin (23.03%). Both extracts of R. officinalis and A. indica exhibited different toxicity against the stored grain pest T. castaneum, with LC₅₀ values of 1.470 and 2.588 mg/ml, respectively. Additionally, after 4 and 5 h of treatment at a concentration of 0.2 mg/ml, the A. indica extract showed the highest levels of repellent action (81.4% and 93.4%), and the R. officinalis extract showed a good repellent rate (64.9% and 80.7%) against T. castenum larvae. With an IC₅₀ value of 35.83 and 28.68 mg/L and a radical scavenging activity percentage of 67.76% and 72.35%, the leaf extract was found to be the most potent plant extract when tested for DPPH antioxidant activity. Overall results showed that MeOH extracts of R. officinalis and A. indica were more effective against S. aureus than E. coli. To determine how the investigated chemicals attach to the active sites of E. coli DNA gyrase A and S. aureus undecaprenyl diphosphate synthase, docking studies were carried out. The consensus score analysis showed that limonene exhibits the best binding energy with both enzymes in docking analysis and more stability in molecular dynamics simulations. The RMSD was obtained at 20.6 and 4.199 (Kcal/mole). The two compounds were successfully used in molecular dynamics simulation research to generate stable complexes with DNA gyrase A.