Judul: Pest attack rate and abundance of predator on shallot plants in Gebang, Pakel, Tulungagung
Abstrak: Bawang merah (Allium ascolonicum L.) merupakan komoditas hortikultura penting dan memiliki nilai ekonomi tinggi. Produktivitas bawang merah di Tulungagung berfluktuasi setiap tahunnya salah satunya disebabkan oleh adanya serangan hama dan penyakit. Penelitian ini bertujuan mengetahui tingkat serangan hama dan kelimpahan predator pada pertanaman bawang merah. Penelitian dilaksanakan pada bulan Januari sampai Mei 2022 menggunakan metode pengamatan langsung di lapangan dan wawancara kepada petani. Pengamatan dilakukan pada 3 petak pertanaman bawang merah milik petani. Setiap petak pertanaman diamati 200 tanaman contoh yang ditentukan secara sistematis. Pengamatan luas dan intensitas serangan hama serta kelimpahan populasi predator dilakukan setiap minggu mulai umur tanaman 1 minggu setelah tanam (MST) sampai 7 MST. Hasil penelitian menunjukkan bahwa hama yang menyerang pada pertanaman bawang merah yaitu Liriomyza chinensis dan Spodoptera exigua. Luas serangan L. chinensis berkisar antara 0–83% dan intensitas serangan berkisar antara 0–54% di ketiga lahan. Sedangkan luas serangan S. exigua berkisar antara 0–9,5% dan intensitas serangan berkisar antara 0–6,92%. Intensitas serangan L. chinensis ada hubungan dengan budi daya tiap lahannya dan intensitas serangan S. exigua tidak berhubungan dengan budi daya tiap lahannya karena jumlah serangan hama sangat rendah pada kategori tertentu. Kemudian predator yang ditemui di pertanaman bawang merah yaitu Pardosa psedoannulata, Menochilus sexmaculatus dan Solenopsis geminata., Shallots (Allium ascolonicum L.) is an important horticultural commodity and has high economic value. The productivity of shallots in Tulungagung fluctuates every year, one of the reason is caused by pests and diseases. This study aims to determine the level of pest attack and the abundance of predator in shallots plant. The research was conducted from January to May 2022 using direct observation in the field and interviews with farmers. The observation was carried out on 3 plots of shallots plant. In every plot 200 plant was sampled systematically. Observation of attack area and intensity of pest attacks and the abundance of natural enemy populations was observed weekly from 17 week after planting. The results showed that the pests in shallots are Liriomyza chinensis and Spodoptera exigua. The attack area and the intensity of L. chinensis ranged from 0-83% and 0-54% in the three plots. The intensity of attack L. chinensis was related to the cultivation of field and the intensity of attack S. exigua was not related to the cultivation of field because the pest attack was low in certain categories. Meanwhile, the attack area and the intensity of S. exigua ranged from 0-9,5% and 0-6,92%. The predators found in shallot are Pardosa psedoannulata, Menochilus sexmaculatus dan Solenopsis geminata.
Keyword: abundance, attack intensity, natural enemies, population

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: 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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