demes nurmayanti

Dengue fever control using chemical methods is often performed by the community due to its immediate and effective results. Control is applied through thermal fogging. Continuous use of chemicals beyond the recommended dose leads to resistance. Methods to determine mosquito resistance include the World Health Organization (WHO) Susceptibility tests using impregnated paper, non-specific esterase enzyme biochemistry using Enzyme-linked immunosorbent assay (ELISA reader), and VGSC gene identification (Voltage Gated Sodium Channel) using PCR (Polymerase Chain Reaction). Kediri Regency has been using Cypermethrin insecticide for one year to prevent resistance. This study aims to predict the resistance of Aedes aegypti mosquitoes to Cypermethrin 0.05% insecticide. This is an observational laboratory study and efficacy test with a cross-sectional design. Third-generation (F3) Aedes aegypti mosquitoes were used as research subjects, with Cypermethrin 0.05% as the insecticide. The study variable is the percentage of mosquitoes that die within 60 minutes and 24 hours post thermal fogging application. Efficacy tests and VGSC gene identification results show that up to the 6th generation (R3), mosquitoes remain susceptible to Cypermethrin 0.05%. The mortality percentage is ≥ 98%, and the non-esterase absorbance value increases from 0.276 (R0) to 0.488 (R3). Further resistance testing using ELISA, PCR, and chromosome examination with the Sanger method continues until mosquitoes show resistance to Cypermethrin 0.05%.

Microplastics can contaminate water owing to their small size. If aquatic biota consume microplastics, they disrupt their reproductive processes, digestive tracts, and development. This study aimed to identify microplastic waste from silkworms (Tubifex spp.) in the Brantas River. The study was conducted in a descriptive manner by collecting samples of microplastic waste from silkworms and examining the shape, type, amount, and percentage of microplastic abundance in the river. An FTIR test was used to determine the microplastic content. Using a Zeiss Axio Zoom.V16 at 50x magnification, microplastic particles from individual worms and worm samples were visually identified. Then, the 50% hot needle test was used to determine the composition of the plastic. A total of 263 microplastic particles were found in the worm samples. Silkworms (Tubifex spp.) in the Brantas River, Kediri City, were shown to contain four types of microplastics, namely fibers, filaments, fragments, and granules, which were dominated by filament particles with 49% filament content, 45% fiber, 5% fragments, and 1% granules. The microplastic polymers identified via FTIR were polyethylene and ethylene-polypropylene-diene copolymers. These microplastics can originate from plastic bags, used drinking bottles, rope fibers, and pieces of water hose, which are often found around the Brantas River. Silkworms found in the Brantas River contain microplastic waste from various pollution sources.