<![CDATA[ABSTRACT Dengue fever was caused by the dengue virus and transmitted through the bites of Aedes aegypti mosquitoes, which lived in stagnant water. Data on dengue fever cases, based on the health profile of Madiun City in 2021, showed a total of 48 cases. This study aimed to determine the effectiveness of lemongrass (Cymbopogon citratus) stem extract as a natural larvicide on the mortality of Aedes aegypti larvae. The type of research used was True Experiment with a Posttest-Only Control Design. The population in this study consisted of third instar Aedes aegypti larvae, with a sample size of 120 larvae and 20 samples in 3 repetitions. Based on the results, the mortality of Aedes aegypti larvae at 15% and 50% concentrations killed 100% of the larvae with varying times of death. The results were then analyzed using the Kruskal-Wallis test, which showed a significant value of 0.017 ≤ 0.05, indicating a difference in larval mortality. This was followed by the Mann-Whitney test, which showed p-values < 0.05 (p=0.003-0.045) for treatments at 15% and 50% concentrations. The conclusion of this study was that lemongrass (Cymbopogon citratus) stem extract was effective in killing larvae and that there was a difference in the mortality of third instar Aedes aegypti larvae with the application of lemongrass stem extract (Cymbopogon citratus). It was hoped that the community could utilize lemongrass as a natural larvicide. Keywords: Third Instar Aedes aegypti Larvae, Lemongrass Stem Extract (Cymbopogon citratus), Killing Power Test. ABSTRAK Demam berdarah disebabkan oleh virus dengue dan ditularkan melalui gigitan nyamuk aedes aegypti dan nyamuk aedes aegypti yang hidup di genangan air. Data penderita DBD berdasarkan data profil kesehatan Kota Madiun Tahun 2021 berjumlah sebanyak 48 kasus. Penelitian ini bertujuan untuk mengetahui efektivitas ekstrak batang serai dapur (cymbopogon citratus) sebagai larvasida alami pada kematian larva nyamuk aedes aegypti. Jenis penelitian ini adalah menggunakan True Eksperiment dengan desain penelitian Posttest-Only Control Design. Dengan Populasi pada penelitian adalah larva nyamuk aedes aegypti instar III dan jumlah sampel sebanyak 120 ekor dan 20 sampel pada 3 pengulangan. Berdasarkan hasil penelitian menunjukkan kematian larva nyamuk aedes aegypti dengan konsentrasi 15% dan 50% dapat membunuh 100% dengan waktu kematian yang bervariasi. Hasil kemudian dianalisis menggunakan uji Kruskal Wallis dan didapatkan nilai sig 0,017 ≤ 0,05 menunjukkan ada perbedaan kematian larva. Maka dilanjutkan pada uji Mann Whitney dengan hasil uji antar kelompok nilai p<0,05 (p=0,003-0,045) pada pelakuan konsentrasi15% dan 50%. Kesimpulan pada penelitian ini menyimpulkan bahwa esktrak batang serai dapur (cymbopogon citratus) efektif dalam membunuh larva dan ada perbedaan kematian larva nyamuk aedes aegypti instar III terhadap permberian esktrak batang serai dapur (cymbopogon citratus). Diharapakan masyarakat dapat memanfaatkan tanaman serai dapur menjadi larvasida alami. Kata Kunci: Larva Aedes Aegypti Instar III, Ekstrak Batang Serai Dapur (Cymbopogon Citratus), Uji Daya Bunuh.]]>
