Judul: Aphis craccivora Koch (Hemiptera: Aphididae) and their control in yardlong bean field
Abstrak: Kacang panjang merupakan tanaman sayuran yang berperan sebagai sumber protein, vitamin, dan mineral. Salah satu hama penting tanaman kacang panjang adalah kutu daun Aphis craccivora. Pengendalian yang umum dilakukan petani terhadap hama ini adalah penggunaan insektisida sintetik. Studi pustaka ini bertujuan memberikan informasi tentang bioekologi kutu daun A. craccivora dan cara pengendaliannya pada pertanaman kacang panjang sebagai dasar penyusunan strategi pengendalian secara terpadu. Pengumpulan data dan informasi dilakukan dengan metode studi pustaka. Tahapan penulisan terdiri dari perumusan masalah, pengumpulan data, analisis, dan simpulan. Berdasarkan studi pustaka, kutu daun mulai ditemukan di pertanaman kacang panjang pada fase bibit, pertumbuhan vegetatif sampai fase generatif. Perkembangan populasinya secara alami dipengaruhi oleh faktor makanan, musuh alami dan faktor lingkungan seperti curah hujan. Pengendalian kutu daun secara terpadu dapat dilakukan dengan budidaya tanaman yang baik, pemanfaatan musuh alami hama, bioinsektisida, insektisida nabati, dan insektisida sintetik sebagai alternatif terakhir. Musuh alami kutu daun antara lain Menochilus sexmaculatus, Ischiodon scutellaris, Aphidius sp., dan Lysiphlebus fabarum. Bioinsektisida Lecanicillium lecanii dan Beauveria bassiana serta insektisida nabati ekstrak daun sirsak, gulma siam, dan daun pepaya berpotensi sebagai sarana pengendalian alternatif yang aman dan ramah lingkungan., Yardlong bean is a vegetable plant that contains high protein, vitamins, and minerals. One of the important pests of the yardlong bean plant is the Aphis craccivora Koch. Farmers often control this pest by using synthetic insecticides. This literature research aims to provide information about the bioecology of A. craccivora and methods to control them in yardlong bean cultivation as the basis for developing an integrated control strategy. Data and information collection were carried out using the literature study method. The writing stages consist of problem formulation, data collection, analysis, and making conclusions. Based on literature studies, aphids appeared to become destructive in yardlong bean plantations on seedling, vegetative growth to generative phase. Aphids population development is often influenced by food factors natural enemies, and environmental factors such as rainfall. Integrated control of aphids can be carried out by good cultivation of plants, utilization of natural enemies of pests, bioinsecticides, botanical insecticides, and synthetic insecticides as a last resort. Natural enemies of aphids include Menochilus sexmaculatus, Ischiodon scutellaris, Aphidius sp., and Lysiphlebus fabarum. Bioinsecticides Lecanicillium lecanii and Beauveria bassiana as well as vegetable insecticides soursop leaf extract, siamese weeds, and papaya leaves have the potential as a means of controlling safe and environmentally friendly alternatives.
Keyword: bioinsecticides, botanical insecticides, sintetic insecticides, natural enemy

Judul: Pod Borer Maruca testulalis (Geyer) (Lepidoptera: Pyralidae)  and Their Control in Yardlong Bean Field
Abstrak: Kacang panjang (Vigna sinensis L.) merupakan salah satu jenis sayuran yang banyak dikonsumsi masyarakat Indonesia. Produktivitas kacang panjang sering terkendala oleh serangan organisme pengganggu tanaman (OPT), salah satunya hama penggerek polong Maruca testulalis. Secara umum, upaya pengendalian hama yang biasa dilakukan adalah menggunakan insektisida sintetik. Penggunaan insektisida sintetik secara terus menerus berdampak negatif terhadap organisme bukan sasaran dan lingkungan. Studi pustaka ini bertujuan memberikan informasi tentang bioekologi M. testulalis dan cara pengendaliannya pada pertanaman kacang panjang. Pengumpulan data dan informasi dilakukan dengan metode studi pustaka. Tahapan penulisan terdiri dari perumusan masalah, pengumpulan data, analisis dan simpulan. Hasil studi pustaka menunjukkan bahwa serangan M. testulalis ditemukan saat tanaman mulai berbunga atau memasuki fase generatif. Intensitas serangan M. testulalis dipengaruhi oleh ketersediaan makanan dan musuh alami. Pengendalian M. testulalis dapat dilakukan dengan memanfaatkan musuh alami seperti parasitoid Trichogramma evanescens, Apanteles taragamae, predator Eocanthecona furcellata, laba-laba Oxyopes javanus dan famili Lycosidae yang ada di pertanaman, serta penggunaan bioinsektisida Bacillus thuringiensis dan Beauveria bassiana, yang mulai dapat diterapkan sejak awal ditemukannya gejala serangan pada tanaman kacang panjang. Penggunaan insektisida nabati ekstrak biji mimba (Azadirachta indica), ekstrak daun sirsak (Annona muricata), ekstrak biji buah hutung (Barringtonia asiatica) dapat digunakan sebagai alternatif pengendalian untuk mengurangi penggunaan insektisida sintetik ketika populasi hama atau kerusakan sudah mencapai ambang pengendalian. Penggunaan insektisida klorantraniliprol, monosultap, klorpirifos, flubendiamida, dan lamda sihalotrin dapat digunakan sebagai alternatif pengendalian terakhir dan dilakukan secara bijaksana., Yardlong bean (Vigna sinensis L.) is a vegetable type that widely consumed by Indonesian. Yardlong bean productivity is often constrained by the attack of plant pests, for example the pod borer Maruca testulalis. The continued use of synthetic insecticides as pod borer control measure by farmers can cause negative impact on environment and non-target organisms. This study outlines the information of M. testulalis bioecology and various control measures it in the yardlong bean field. Data and information collection were carried out using the literature study method. The writing stages consist of problem formulation, data collection, analysis, and making conclusions. Based on literature studies, the attack of M. testulalis was found when the plants began to flower or entered the generative phase. The intensity of M. testulalis attack was influenced by the availability of food and natural enemies. Control of M. testulalis could be done by utilizing natural enemies such as the parasitoid of Trichogramma evanescens, Apanteles taragamae, predators of Eocanthecona furcellata, Oxyopes javanus, and the Lycosidae spiders family in the field, also the use of bioinsecticide of Bacillus thuringiensis and Beauveria bassiana, which can be applied since the initial symptoms of an attack on yardlong bean plant. Botanical insecticide of extraction from neem seed (Azadirachta indica), soursop leaf (Annona muricata), and hutung fruit seed (Barringtonia asiatica) could be used as an alternative to reduce the use of synthetic insecticides when the pest or damage population has reached the control threshold. Synthetic insecticides of chloranthraniliprol, monosultap, chlorpyrifos, flubendamide, and lamda cyhalothrin could be used as a last alternative to control and carried out wisely.
Keyword: bioinsecticide, botanical insecticide, Natural enemies, synthetic  insecticide

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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