UJI BIOAKTIVITAS EKSTRAK KLOROFORM RHIZOPHORA APICULATA (MANGROVE) TERHADAP SPODOPTERA LITTURA FABR. SEBAGAI INSEKTISIDA NABATI (TEST OF BIOACTIVITY CHLOROFORM EXTRACT FROM BARK OF RHIZOPHORA APICULATA TO SPODOPTERA LITTURA FABR. AS BIOINSECTICIDE)

Abstract

Abstrak.Penelitian ini bertujuan untuk mengetahui bioaktivitas dari ekstrak kloroform kulit batang tumbuhan Rhizophora apiculata (EKRA) terhadap ulat grayak (Spodoptera Littura Fabr.) meliputi mortalitas, LC₅₀. Pengujian bioaktivitas insektisida terhadap pertumbuhan ulat grayak menggunakan metode semprot dan celup agar diyakini terjadinya racun kontak atau racun perut. Konsentrasi ekstrak EKRA yang diujikan adalah K0= kontrol, K1= 200 mg/L, K2= 400 mg/L, K3= 800 mg/L, K4= 1600 mg/L, K5= 3200 mg/L, K6= 6400 mg/L dengan perlakuan diulang sebanyak 4 kali. Hasil dari persentase mortalitas ekstrak kloroform tersebut adalah 0%, 25 %, 26,7 %, 33,3 %, 36,7 %, 45 %, dan 55 %. nilai LC₅₀ ditentukan dengan analisis probit menggunakan program Minitab 14 for windows. Hasil uji bioaktivitas larvasida memberikan nilai LC₅₀ untuk 24, 48, dan 78 jam setelah perlakuan berturut-turut untuk EKRA adalah 9009,573 mg/L; 8550,761 mg/L; dan 4759,487 mg/L. Dengan demikian, ekstrak kulit batang tumbuhan Rhizophora apiculata (EKRA) dapat dijadikan alternatif bioinsektisida.

Kata kunci: Bioaktivitas, Ekstrak kloroform, Rhizophora apiculata, Spodoptera littura Fabr.

Abstract.The aim of this research is to determine to know the insectisidal bioactivity of chloroform extract of plant Rhizophora apiculata bark (EKRA) with Spodoptera littura as the target insects include mortality, LC₅₀. On the other hand, chloroform extract of stem bark of Rhizophora apiculata were also tested the insecticidal bioactivity using to spray and dip method that occurs contact poison or stomach poison. The experiment of insecticidal bioactivity test used seven various of concentrations and was multiplied with 4 replicates. Concentrations for the chloform extract are 0, 200, 400, 800, 1600, 3200, and 6400 mg/L. Results of percentage mortality of the chloroform extract was 0%, 25%, 26,7%, 33,3%, 36,7%, 45 %, dan 55%. Based on insecticidal bioactivity test, LC₅₀ value was determined by probit analysis using programme Minitab 14 for windows. Insecticidal bioactivity test gave the LC₅₀ value for 24, 48, and 72 hours after treatments for chloroform extract are 9009,573 mg/L; 8550,761 mg/L; and 4759,487 mg/L. So, the bark extract of the plant Rhizophora apiculata (EKRA) may be an alternative plant-based insecticides.

Keywords: Bioaktivitas, Chloroform extract, Rhizophora apiculata, Spodoptera littura Fabr.