Repellency and Insecticidal Activity of Some Botanical Extracts and Oils on Storage Pest of Ephestia cautella

Abstract
Description
Ephestia cautella is one type of storage pests that causes a decrease in cocoa bean quality. Control of this pest using chemical insecticides is not recommended because it is harmful to the environment and consumer health. The research aimed to examine the repellency and insecticidal activity of several types of extract and botanical oil against E. cautella larvae. The research was conducted in the Plant Protection Laboratory, Indonesian Industrial and Beverage Crops Research Institute, from March to November 2012. Botanical materials used were water extracts from Ageratum conyzoides leaves, Azadirachta indica seeds, and Allium sativum tubers, as well as oil from Reutalis trisperma, Syzygium aromaticum, and Andropogon nardus, with respective concentration of 0.5%. The insects test used was the 3rd instar larvae generated in the laboratory. Preliminary testing of the repellency activity was performed used the multiple-choice method, while subsequent testing used the dual-choice method with the parameters of larvae number remains in each treatment until 72 hours. The insecticidal activity was conducted using residual method on the feed substitute, by calculating mortality rate of the test insects. Observations were made at 24, 48, and 72 hours after treatment. The results showed that water extract from A. sativum bulbs and A. conyzoides leaves have high repellency percentage on the  E. cautella larvae, i.e. of 81.33% and 78.67%, respectively. Thus, these two vegetable extracts have the potential to be used as cocoa bean protectant from storage pest attacks. The extracts from A. indica seed, A. sativum bulbs, as well as oil from R. trisperma and S. aromaticum showed insecticidal properties that are able to kill E. cautella larvae.
Ephestia cautella merupakan salah satu jenis hama gudang yang menyebabkan penurunan kualitas biji kakao. Pengendalian hama ini menggunakan insektisida kimia tidak dianjurkan karena berbahaya bagi lingkungan dan kesehatan konsumen. Tujuan penelitian adalah menguji aktivitas repelensi dan insektisidal dari beberapa jenis ekstrak dan minyak nabati terhadap larva E. cautella. Penelitian dilaksanakan di Laboratorium Proteksi Tanaman, Balai Penelitian Tanaman Industri dan Penyegar (Balittri), mulai bulan Maret sampai November 2012. Bahan nabati yang digunakan adalah ekstrak air dari daun Ageratum conyzoides, biji Azadirachta indica, dan umbi Allium sativum, serta minyak dari Reutalis trisperma, Syzygium aromaticum, dan Andropogon nardus dengan konsentrasi masing-masing 0,5%. Serangga uji yang digunakan adalah larva instar ke-3 hasil perbanyakan di laboratorium. Uji pendahuluan terhadap aktivitas repelensi menggunakan metode banyak pilihan (multiple-choice), sedangkan uji lanjutan menggunakan metode dua pilihan (dual-choice) dengan parameter jumlah larva yang menetap pada masing-masing perlakuan sampai 72 jam setelah perlakuan. Uji aktivitas insektisidal menggunakan metode residual pada pakan pengganti dengan menghitung tingkat mortalitas serangga uji. Pengamatan dilakukan pada 24, 48, dan 72 jam setelah perlakuan. Hasil penelitian menunjukkan persentase repelensi ekstrak air dari umbi A. sativum dan daun A. conyzoides terhadap larva E. cautella tergolong tinggi, yaitu masing-masing 81,33% dan 78,67%. Dengan demikian, kedua ekstrak nabati tersebut berpotensi menjadi bahan pelindung biji kakao dari serangan hama gudang E. cautella. Ekstrak dari biji A. Indica dan umbi A. sativum serta minyak dari R. trisperma dan S. aromaticum menunjukkan indikasi bersifat insektisidal yang mampu mematikan larva E. cautella. 
Keywords
Citation