Judul: Biologi kepik predator Rhynocoris fuscipes(F.)(Hemiptera:Reduviidae) pada tiga jenis mangsa
Abstrak: Peranan predator generalis penting untuk mencegah peledakan populasi hame, terutama pada areal pertanaman monokultur, karena dapat bertindak sebagai suatu roda penyeimbang di dalam populasi hama yang kompleks. Kepik Reduviidae merupakan salah satu famili terbesar dari Ordo Hemiptera, nimfa maupun imagonya berperan sebagai predator serangga lain, dan Rhynocoris spp. merupakan anggota Reduviidae yang berpotensi dikembangkan dalam pengendalian hayati. Penelitian ini bertujuan untuk meneliti pengaruh pemberian tiga jenis mangsa yang berbeda terhadap beberapa variabel biologi penting pada satu siklus hidup kepik predator R. fuscipes. Penelitian ini dilaksanakan di Laboratorium Bioekologi Hama. Departemen Proteksi Tanaman, Fakultas Pertanian, Institut Pertanian Bogor, dan berlangsung sejak Nopember 2006 sampai dengan Mei 2007. Parameter yang diamati dalam penelitian ini antara lain morfologi kepik predator yang terdiri dari warna, bentuk, panjang telur dan tubult, bobot tubuh nimfa dan imago- kepik predator, kemudian biologi kepik predator yang terdiri dan jumlah mangsa yang dibunuh oleh nimfa dan imago, jumlah mangsa yang cairannya diserap oleh imago, banyaknya biomassa yang diserap oleh nimfa dan imago, efisiensi konsumsi predator terhadap mangsa, mortalitas nimfa dan imago, lama hidup tiap instar nimfa dan imago, frekuensi bertelur, masa praoviposisi dan oviposisi, keperidian, dan persentase keberhasilan penetasan telur. Kemampuan membunuh R. fuscipes lebih tinggi dibandingkan dengan kemampuan memangsa untuk memenuhi kebutuhan nutrisi dari mangsanya. Dari keseluruhan hasil yang diperoleh berdasarkan banyaknya mangsa yang dibunuh. dimangsa, bobot mangsa yang diserap, bobot predator, mortalitas, ECI, siklus hidup yang pendek, masa praoviposisi, masa oviposisi yang paling singkat, dan frekuensi peneluran dan keberhasilan penetasan telur yang paling tinggi dan aktivitas memangsa, dapat disimpulican mangsa P. xylostella dengan pakan caisin tanpa pupuk lebih sesuai sebagai mangsa kepik predator R. fuscipes, sedangkan mangsa S. litura dinilai paling tidak sesuai dibandingkan jenis mangsa lain yang diujikan.
Keyword: Kepik predator, Rhynocoris spp., Pemeliharaan Rhynocoris fuscipes (F), Serangga predator

Judul: Pengaruh Tiga Jenis Mangsa terhadap Biologi Kepik Predator Sycanus annulicornis Dohrn. (Hemiptera: Reduviidae)
Abstrak: The objective of the research was to study the effects of (1) three different spesies of preys on the biology of predator S. annulicornis, (2) ratio of female to male on the fecundity and fertility of the predator, and (3) prey status on the predator behaviors. The research was held at Ecology Laboratory, Departemen Proteksi Tanaman, Fakultas Pertanian, IPB, since July 2005 until June, 2006. Predator S. annulicornis was collected from agricultural field of Kebun Percobaan IPB Sawah Baru and Situ Gede, Darmaga Bogor. Preys used were Corcyra cephalonica Stainton (Lepidoptera: Pyralidae), Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae), and Spodoptera litura Fabricius (Lepidoptera: Noctuidae), both as dead and alive larvae. Larvae and adult of C. cephalonica was collected from rice warehouse at Cianjur and surroundings, larvae T. molitor from local market at Bogor, while larvae S. litura from soybean fields at Kampus IPB Darmaga. Those preys then were reared in the laboratory. The study revealed that C. cephalonica was the most suitable prey for S. annulicornis. It resulted in the lower mortality rate (17,5%), shorter nymphal period (51,42 days), longer longevity (30,25 days), higher adult weight (0,12 g) and higher ECI value (33,46%). On the other hand, S. litura was unsuitable prey for S. annulicornis. It resulted in higher mortality rate (70%), longer nymphal period (58,31 days), shorter longevity (18,50 days), lower adult weight (0,07 g), and lower ECI value (8,32%). The sex ratio of 1:2 was the most suitable for mass rearing of the predator in laboratory, because it generated highest fecundity (74,14 eggs) and highest fertility (65,14 eggs). Prey given as dead larvae did not affect the predatory behavior of the offsprings.
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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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