Aktivitas biologi ekstrak daun Nicolaia atropurpurea Val. terhadap serangga hama Spodoptera litura Febricus (Lepidoptera:Noctuidae)

ASMALIYAH, Prof. Dr. Ir. Sumardi, M.For.Sc

2009 | Tesis | S2 Ilmu Kehutanan

N. atropurpurea (zingiberaceae) secara tradisional telah dimanfaatkan masyarakat lokal sebagai insektisida nabati untuk melindungi tanaman budidaya dari serangan hama Namun sampai sekarang penggalian ilmiah terhadap potensi aktivitas biologinya terhadap serangga belum pernah diteliti. Penelitian ini dilakukan untuk mengetahui hal tersebut dan sekaligus untuk mengetahui pengaruh cara ekstraksi, jenis pelarut, konsentrasi dan frekuensi aplikasinya terhadap aktivitas biologi ekstrak daun N. atropururea. Penelitian dilakukan dalam 3 percobaan, yaitu : Percobaan 1, pengujian pengaruh cara ekstraksi dan jenis pelarut terhadap aktivitas biologi esktrak daun N. atropurpurea dengan metode residu daun dan kontak. Percobaan menggunakan RAL dengan perlakuan 6 taraf konsentrasi dengan 3 ulangan. Percobaan 2, pengujian toksisitas (LC50 dan LC95) ekstrak etil asetat daun N. atropurpurea dengan metode kontak. Percobaan menggunakan RAL dengan perlakuan 6 taraf konsentrasi dengan 3 ulangan. Percobaan 3, pengujian pengaruh konsentrasi dan frekuensi aplikasi terhadap aktivitas biologi ekstrak etil asetat daun N. atropurpurea dengan metode kontak. Percobaan menggunakan RAL dengan 2 faktor, yaitu konsentrasi (6 taraf) dan frekuensi aplikasi (3 taraf) dengan 3 ulangan. Parameter yang diamati, jumlah larva ganti kulit, mortalitas larva, lama periode larva dan pupa, jumlah imago yang muncul, aktivitas makan dan pertumbuhan larva serta berat pupa. Hasil penelitian menunjukkan bahwa : (1) ekstrak daun N. atropurourea bersifat toksik terhadap S. litura, memperpanjang lama periode larva, menghambat aktivitas makan dan menurunkan laju pertumbuhan serta menurunkan berat pupa ketika diaplikasikan secara kontak, (2) ekstrak etil asetat hasil ekstraksi maserasi bertingkat mempunyai toksisitas paling tinggi dengan nilai LC50 dan LC95 berturutturut sebesar 0,18% dan 0,54%, dan (3) semakin tinggi konsentrasi dan frekuensi aplikasi ekstrak etil asetat daun N. atropurpurea, semakin tinggi pula aktivitas biologi ekstrak terhadap serangga S. litura

N. atropurpurea (zingiberaceae) has commonly been used by local people as botanical insecticides to protect agricultural crops and forest plantation from insect. Although, its scientific basis have not been yet available. This research was done to fill the gap. Three experiments were done in this study: Experiment 1, study on the effect of extraction method and solvent used for extraction on bioactivity of N. atropurpurea leaf extract were carried out using leaf residue and direct contact methods. A completely randomized design with 3 replications.. Treatments consisted of six of concentration level. Experiment 2, study on toxicity (LC50 and LC95 value) of ethyl acetate of N. atropurpurea leaf extract were carried out using direct contact method. A completely randomized design with 3 replications. Treatment consisted of concentrations level six.. Experiment 3, study on the effect of concentration and application frequency on the bioactivity of ethyl acetate of N. atropurpurea leaf extract when it were carried out by using direct contact method. A completely randomized design with two factors, i.e concentration (6 level) and frequency of application (3 level) with 3 replications was applied in the experiment. Larval mortality, the number of molting larvae, duration of larval and pupal period, percentage of adult emergence, feeding activity, growth and development of larvae, and pupal weight were observed. The Results showed that : (1) N. atropurpurea leaf extract were toxic to the larvae of S.litura when it applied with direct contact method. The other observed effect were prolonged duration of larval period; inhibited feeding activity; reduced growth and development of larvae and decreased pupal weight, (2) Ethyl acetate extract produced by soaking method show the highest toxicity, with LC50 and LC95 values of 0,18 % and 0,54 %, respectively, and (3) The higher concentration and application frequency of ethyl acetate of N. atropurpurea leaf extract, the higher the bioactivity of extract.

Kata Kunci : Aktivitas biologi, ekstrak daun Nicolaia atropurpurea, Spodoptera litura, Biological activity, N. atropurpurea leaf extract