Judul: Diversity of Predators in Shallots, Cayenne Peppers and Tomatoes in Kediri Regency, East Java
Abstrak: Kegiatan bercocok tanam termasuk produksi tanaman hortikultura memiliki banyak faktor pembatas ataupun kendala seperti gangguan dari organisme pengganggu tanaman (OPT). Umumnya OPT dikendalikan dengan menggunakan pestisida yang dapat berdampak buruk pada lingkungan dan manusia. Oleh karena itu perlu penerapan teknik pengendalian yang lebih berwawasan lingkungan. Penggunaan predator sebagai agen hayati yang dominan di lapangan merupakan bagian yang penting dalam sistem pengendalian hama terpadu (PHT). Penelitian ini bertujuan mengetahui keragaman predator pada tanaman hortikultura seperti bawang merah, cabai rawit, dan tomat di Kecamatan Pare (Desa Pelem, Desa Sekoto) Kabupaten Kediri, Jawa Timur. Metode yang digunakan untuk mengetahui keragaman predator pada bawang merah adalah dengan pengamatan lapang menggunakan jaring serangga, pitfall trap, dan penghisap debu. Pada tanaman cabai rawit dan tomat melakukan pengamatan lapang menggunakan jaring serangga, pitfall trap, dan shaking. Identifikasi serangga predator yang diperoleh dilakukan di Laboratorium Ekologi Serangga, Departemen Proteksi Tanaman, Fakultas Pertanian, IPB University mengacu pada buku identifikasi Pengenalan Pelajaran Serangga edisi ke enam Borror et al. (1989). Analisis nilai keragaman menggunakan indeks keanekaragaman α (indeks keanekaragaman Shannon-Wienner, Simpson dan Eveness). Data diolah menggunakan program XLSTAT 2014. Serangga predator yang ditemukan pada lahan pengamatan di Kecamatan Pare, Kabupaten Kediri, Jawa Timur sebanyak 4815 individu yang termasuk ke dalam total 45 spesies serangga predator dengan tingkat keragamaan pada masing-masing komoditas berbeda. Spesies serangga predator yang paling banyak ditemukan di pertanaman bawang merah, cabai rawit, dan tomat secara berturut-turut yaitu Paederus fuscipes, Anoplolepis gracilipes, dan Metioche vittaticollis. Hasil pengamatan menunjukkan bahwa komunitas serangga predator melimpah pada semua agroekosistem. Hal tersebut menjadi modal dasar yang baik untuk menjaga keseimbangan ekosistem., Farming activities including the production of horticultural crops, have many limiting factors or constraints such as disturbances from pest and plant diseases. Generally, pests are controlled by using pesticides which can harm the environment and humans. Therefore it is necessary to apply control techniques that are more environmentally friendly. The use of predators as the dominant biological agent in the field is an important part of an integrated pest control system. This research aimed to determine the diversity of predators in horticultural crops (shallot, cayenne pepper, and tomatoe) in the Pare District, Kediri Regency, East Java. The samples collected on shallot plants were made by field observations using insect nets, pitfall traps, and vacuum cleaners, while on cayenne pepper and tomato plants were made using insect nets, pitfall traps, and shaking the plant's shoot. The identification of predator insects was done by referring to the sixth edition of the identification book on Introduction to Insect Lessons, Borror et al. (1989). Diversity value analysis used diversity index α (Shannon-Wienner, Simpson, and Eveness diversity index). The data was processed using the XLSTAT 2014 program. Based on the result, 4815 insect predators were found in the observation areas in Pare District, Kediri Regency, which included a total of 45 insect species with different levels of diversity in each commodity. The most predator species found in shallot, cayenne pepper, and tomato plantations were Paederus fuscipes, Anoplolepis gracilipes, and Metioche vittaticollis, respectively. The observations showed that predator insect communities are abundant in all agroecosystems. This is a good
Keyword: biological control, natural enemies, pitfall traps, population, shaking

Judul: Serangga Hama dan Artropoda Lain pada Pertanaman Cabai Rawit (Capsicum frutescens L.) di Desa Margoluwih, Kecamatan Seyegan, Kabupaten Sleman.
Abstrak: Cabai rawit merupakan salah satu komoditas hortikultura penting di Indonesia. Dalam budi daya tanaman cabai petani umumnya menggunakan teknik-teknik konvensional meskipun teknik tersebut dapat menimbulkan dampak buruk pada populasi hama dan ekosistemnya. Penelitian ini bertujuan mengetahui perkembangan populasi hama cabai rawit dan melihat kelimpahan artropoda tanah pada lahan tanaman cabai yang dibudi dayakan secara konvensional di Sleman Yogyakarta. Lahan tanaman cabai dibagi menjadi lima petak pengamatan yang masing-masing berukuran 5 m x 20 m. Pengamatan hama secara langsung dilakukan terhadap 20 tanaman contoh pada tiap petak pengamatan yang diambil dengan metode dua diagonal. Tanaman cabai rawit diamati dari umur 3 MST (minggu setelah tanam) hingga 15 MST dengan interval pengamatan 7 hari. Pada fase vegetatif (3-5 MST), pengamatan dilakukan terhadap seluruh bagian tanaman cabai, sedangkan memasuki fase generatif pengamatan dilakukan terhadap semua pucuk tanaman cabai hingga 5 daun ke bawah. Kelimpahan artropoda diamati menggunakan perangkap pitfall. Hasil penelitian menunjukkan bahwa populasi hama lebih variatif ketika tanaman memasuki fase generatif dibandingkan dengan fase vegetatif. Spesies serangga hama yang paling mendominasi pada penelitian ini ialah kutu daun sebanyak 23.175 individu, Bemisia tabaci 1.761 individu, dan Spodoptera litura 201 individu. Artropoda lain yang mendominasi pada penelitian ini tergabung dalam kelompok famili Formicidae sebanyak 979 individu. Kata kunci: artropoda, budi daya, cabai rawit, serangga hama, Cayenne pepper is one of the important horticultural commodities in Indonesia. In chili cultivation, the majority of farmers still use conventional techniques that have a negative impact on the pest populations and their ecosystems. This study aims to determine the population development of cayenne pepper insect pests and the abundance of soil arthropods on cayenne pepper field cultivated conventionally in Sleman, Yogyakarta. A cayenne pepper field was divided into five plots of 5 m x 20 m each. Observations of insect pests were carried out directly on 20 sample plants in each observation plot taken with two diagonal method. Cayenne pepper was observed from the age of 3 WAP (weeks after planting) to 15 WAP with an observation interval of 7 days. All parts of the sample plants were observed when cayenne pepper was in vegetative phase (3-5 WAP), and all shoots with 5 top leaves were observed when the plants in the generative phase. Arthropod abundance was observed using pitfall traps. The results showed that the pest population was more varied when the plant entered the generative phase compared to the vegetative phase. The most dominant insect pest species in this study were aphids as many as 23175 individuals, Bemisia tabaci 1761 individuals, and Spodoptera litura 201 individuals. Ants (Hymenoptera: Formicidae) (as many as 979 individuals) were the most abundant arthropods trapped in pitfall traps set in cayenne pepper field. Keywords: arthropods, cayenne pepper, cultivation, insect pests
Keyword: arthropods, cayenne pepper, cultivation, insect pests

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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