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Evaluation of Certain Synthetic and Natural Pesticides Against Whitefly Bemisia tabaci (Genn.) on Green Bean and Effect on Honeybee Apis mellifera L.
2023
Ahmad, Sharihan | Abdelghany, Walaa | Ahmed, Ahmed | Abdelmegeed, Sawsan
The green bean crop (Phaseolus vulgaris) is infested with many insects such as whiteflies (Bemisia tabaci). An investigation was carried out to study the insecticidal activity of whitefly (Bemisia tabaci), five pesticides were used, namely Thiamothoxam, Sulfoxaflor, Spirotetramat, Pymetrozine, and Flonicamid, and three commercial natural pesticides, namely Superrego, Topnine, and Bernastar. Pesticides and natural pesticides were sprayed during the two seasons of 2020 and 2021. The obtained results in terms of the reduction rate of the insects' number were as follows: The highest rate of reduction appeared in Thiamothoxam and Sulfoxaflor treatments, where it reached above 80%, while the other pesticides were in the range of 40% to 60%, and the lowest reduction rate was 34.33% and 36.00 % for Bernastar during season 2020 and 2021 respectively. When evaluating the toxicity of these pesticides and natural pesticides against honeybees (Apis mellifera), the pesticides did not reveal any toxicity to honeybees, except for Thiamothoxam, Sulfoxaflor, and Superrego The LC50 and LD50 values against honeybees were 0.2 ppm and 0.000005µg/one honeybee for Thiamothoxam, 4.5 ppm and 0.0001125 µg/one bee for Sulfoxaflor, and 0.95 ppm and 0.00002375 µg /one bee for Superego respectively.
Show more [+] Less [-]Frequency Incidence of Tomato Chlorosis Virus and Tomato Yellow Leaf Curl Virus Affecting Tomato Plants
2024
Wael El-Araby | Ahmed Al Attar | Baadawi Othman | Khaled Eldougdoug
The Tomato Chlorosis Criniviruses (ToCV) and Tomato yellow leaf curl Geminivirus (TYLCV), which naturally infecting and limited to the phloem, have caused a drastic reduction in tomato yield. The current study aims to determine the incidence of single and mixed viruses using biological, serological and molecular PCR methods in natural tomato plants. The incidence of mixed infection was found more frequently, followed by ToCV and TYLCV (42.3, 28.8, 17.8 in 2020 and 49.1, 29.7 and 19.1% in 2021, respectively). ToCV causes chlorosis, TYLCV causes leaf curl and yellowing, while mixed ToCV & TYLCV cause progress symptoms. By using the heat shock protein 70 (HSP70) and coat protein (CP) genes, ToCV and TYLCV isolates could be identified. These isolates were recorded in GenBank under accession codes "ON951644.1" and "OP265136.1" respectively. Host plants responded differently to severe and common disease density between ToCV and TYLCV. The transmitted whitefly could distinguish between ToCV and TYLCV within 15-20 minutes of the acquisition period. ToCV increases in fields with high whitefly populations, requiring further research to understand effects and reduce harm.
Show more [+] Less [-]Some Natural and Chemical Compounds Directly Affect Pests of Mulberry Trees and Their Side Effects on Silkworm Larvae
2024
Mai Hassanein | Youssef Abdalla | Sawsan Abdelmegeed
Mulberry trees suffer from many pest infestations. To control these pests, some natural compounds such as Techno Oil and Top 9 and some other chemicals such as Mospilan® and Chinook® were used. Mulberry trees, Morus nigra were treated with three different concentrations of each of Chinook, Techno Oil® and Top 9® to reduce infestation with Icerya sp. and Ferrisia virgate. A high reduction rate of more than 90% occurred when using these pesticides. On the other hand, the corrected mortality of mulberry silkworm larvae was 93.3%, 0.0% and 6.7% respectively after 8 days of treatment. When treating mulberry trees Morus alba with two different concentrations of each of pesticides; Mospilan and Techno Oil against whitefly, the average rate of infestation reduction was 100% and 94.94%, respectively. The corrected mortality of mulberry silkworms' larvae was 100% and 0.0% after 8 days of treatment respectively. This study proved that natural compounds could be used safely instead of chemical pesticides to reduce the pest population without affecting the life of silkworm larvae or cocoon properties.
Show more [+] Less [-]Evaluation of Certain Synthetic and Natural Pesticides Against Whitefly Bemisia tabaci (Genn.) on Green Bean and Effect on Honeybee Apis mellifera L.
2023
Sharihan Ahmad | Walaa Abdelghany | Ahmed Ahmed | Sawsan Abdelmegeed
The green bean crop (Phaseolus vulgaris) is infested with many insects such as whiteflies (Bemisia tabaci). An investigation was carried out to study the insecticidal activity of whitefly (Bemisia tabaci), five pesticides were used, namely Thiamothoxam, Sulfoxaflor, Spirotetramat, Pymetrozine, and Flonicamid, and three commercial natural pesticides, namely Superrego, Topnine, and Bernastar. Pesticides and natural pesticides were sprayed during the two seasons of 2020 and 2021. The obtained results in terms of the reduction rate of the insects' number were as follows: The highest rate of reduction appeared in Thiamothoxam and Sulfoxaflor treatments, where it reached above 80%, while the other pesticides were in the range of 40% to 60%, and the lowest reduction rate was 34.33% and 36.00 % for Bernastar during season 2020 and 2021 respectively. When evaluating the toxicity of these pesticides and natural pesticides against honeybees (Apis mellifera), the pesticides did not reveal any toxicity to honeybees, except for Thiamothoxam, Sulfoxaflor, and Superrego The LC50 and LD50 values against honeybees were 0.2 ppm and 0.000005µg/one honeybee for Thiamothoxam, 4.5 ppm and 0.0001125 µg/one bee for Sulfoxaflor, and 0.95 ppm and 0.00002375 µg /one bee for Superego respectively.
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