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A Technological Plan of Studies on Green Chemistry of Environmental Pesticides in 2023.

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This project, in accordance with the goals and tasks of environmental protection policies, and in response to the needs of social and environmental sustainable development, consists of four major work items: The first item involves planning and analyzing the feasibility of internationally recognized environmentally friendly chemical alternatives for pesticides and completing the substitution of chemical agents with green alternatives. The second item according to the discriminating dose (concentrations) of vector pests established in 2022, efforts were made to carry out a wide range of rapid resistance analysis and cross-resistance research on commonly used pesticides, exploring the impact of environmental health pesticides on pests during climate change, and devising corresponding measures. The third item involves planning and completing the establishment of techniques for the application and control of adult mosquitoes through attractants. This is aimed at addressing the need for controlling mosquitoes, which are vectors for dengue fever in Taiwan. The fourth item aims to establish technical specifications for the detection of the efficacy of environmental pesticides. This includes various formulations such as paste, capsule suspension (including microcapsule suspensions), and sand granules. These specifications serve as a reference for the announcement of criteria in reviewing the results of environmental pesticide performance in the "Control Efficacy Testing Results Evaluation Standards for Environmental Agent Permit Registrations." They also provide essential requirements for the application, issuance, and management of environmental pesticides, with the goal of advancing pest control technology and establishing a comprehensive control system. Results of the project: Six plant-based components, including two plant essential oil products and four plant essential oil extracts, were tested for susceptibility and efficacy against common environmental pests (mosquitoes, cockroaches, flies, and ants). The results show that these six plant-based components can be used as alternatives when tested by the glass vial method against the Drosophila melanogaster and the Dolichoderus thoracicus. Neem oil and sweet orange (Citrus sinensis) essential oil, when tested with the residual contact method, are found to be suitable alternatives for mosquitoes, cockroaches, Musca domestica, Drosophila melanogaster, and Dolichoderus thoracicus. Neem oil products and essential oil of Alpinia zerumbet are identified as alternatives for mosquitoes, Musca domestica, Drosophila melanogaster, and Dolichoderus thoracicus. When tested by the immersion method on mosquito larvae, all six plant-based components, except for neem oil products, are found to be suitable alternatives for mosquitoe larvae, except Aedes albopictus larvae. According to the discriminating doses (concentrations) of pesticides established in 2022, a rapid resistance bioassay was conducted on common environmental pests in Taiwan. The Wanluan strain of Aedes albopictus exhibits possible resistance to three organophosphorus pesticides (chlorpyrifos, fenitrothion, and pirimiphos-methyl) and two other types of pesticides (propoxur and imidacloprid). The Donggang strain is resistance to imidacloprid and possible resistance to pirimiphos-methyl. The Donggang strain of Aedes aegypti exhibits resistance to fenitrothion and imidacloprid and also displays cross-resistance. The Wanluan strain of Aedes aegypti has possible resistance to fenitrothion, chlorpyrifos, and pirimiphos-methyl, along with resistance and cross-resistance to propoxur, imidacloprid, and multiple resistance. The Fangliao strain of Aedes aegypti has resistance to imidacloprid. The Puli strain of Blattella germanica exhibits resistance and cross-resistance to four pyrethroids, resistance to pirimiphos-methyl, and multiple resistance. The Zhushan and Caotun strains of Blattella germanica show cross-resistance to pyrethroid and other types of pesticides, along with multiple resistance. Five wild strains of Periplaneta americana show no resistance or cross-resistance to four common pyrethroids, three organophosphorus pesticides, and three other types of pesticides. Five wild strains of the Mosca domestica exhibit resistance and cross-resistance to four common pyrethroids, three organophosphorus pesticides, and three other types of pesticides, displaying multiple resistance.The Puli strain and Mingjian strain of Drosophila melanogaster show resistance to imidacloprid, while the Zhushan strain, Caotun strain, and Jiji strain exhibit resistance and cross-resistance to cypermethrin, permethrin, deltamethrin, and imidacloprid, displaying multiple resistance. Five wild strains of Telmatoscopus albipunctatus show no resistance or cross-resistance to four common pyrethroids, three organophosphorus pesticides, and three other types of pesticides. The liquid attractive toxic sugar bait and station attractive toxic sugar bait have been successfully developed. After conducting efficacy test by cage tests and indoor simulations to verify the feasibility of bait formulations and application methods, further field studies were performed. The monitoring results of the field studies after the application of the baits reveal the following: In the areas where liquid attractive toxic sugar bait and station attractive toxic sugar bait were applied in the first control, there is a reduction in density of vector mosquito eggs by 20.15% and 31.20%, respectively. While the control group shows an increase in density of 9.77%. In the areas where liquid attractive toxic sugar bait and station attractive toxic sugar bait were applied in the second control, there is a reduction in mosquito egg density by 6.22% and 8.92%, respectively. While the control group exhibits an increase in density of 66.39%. In the areas where liquid attractive toxic sugar bait and station attractive toxic sugar bait were applied in the third control, there is a reduction in density of vector mosquito eggs by 38.98% and 34.35 %, respectively. While the control group exhibits an increase in density of 33.75%. These results demonstrate that both types of attractive toxic sugar baits effectively suppressed the local population density of mosquitoes. However, it is important to note that their effectiveness can be compromised by heavy rainfall, which may wash away the bait. It is recommended that when applying these baits, consideration should be given to weather conditions in the application area, and the frequency of control measures should be adjusted as needed. The establishment of efficacy test of the immersion method for sand granules has been completed. The establishment of efficacy test of glass column method and residual contact method for capsule suspension (including microcapsule suspensions) has been accomplished. The establishment of efficacy test of the two-choice and no-choice trials for paste has been accomplished.These establishments will serve as references for future announcements. The current progress of this project has achieved 100.00% completion of all work items, meeting the 100.00% milestone for the achievement report. Furthermore, the project has fulfilled with the requirements of two working meetings.
Keyword
environmental pests, rapid pesticide resistance bioasays, bioassay, discrimination dose (concentration), green chemistry, attractive toxic sugar baits
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