Judul: Pengaruh Cendawan Endofit terhadap Biologi dan Pertumbuhan Populasi Polyphagotarsonemus latus Banks (Acari: Tarsonemidae) pada Tanaman Cabai
Abstrak: Broad mite Polyphagotarsonemus latus is one of the most important pests of pepper. High population of P. latus on pepper may cause death on plants. One of the alternative environmental-friendly control methods is the use of endophytic fungi. This study aimed to know effect of the endophytic fungi on biology and population growth of broad mite on pepper. The pepper seeds were soaked in miselium suspension for 12 hours and then planted. Three weeks after seeds planting, peppers were sprayed with miselium suspension. Broad mite collected from the field were reared on pepper in the laboratory. The same age-five female adults were infested on each pepper seedling a week after last inoculation of endophytic fungi. The population growth of broad mite were observed each week for 10 weeks. In the laboratory, 50 broad mite eggs were reared on pepper leaves and observed every 6 hours until adult emergence. P. latus then paired and observed everyday until all adults dead. Life cycle, fecundity, sex ratio and adult longevity were observed. The result showed that treatment of endhophytic fungi could increase pepper seeds viability. Several kinds of endophytic fungi also suppressed population growth, elongated praoviposition period, reduced mite fecundity and increase the number of male.
Keyword: population growth, Polyphagotarsonemus latus, endophytic fungi, pepper

Judul: Pengaruh Cendawan Endofit Entomopatogen Lecanicillium lecanii (Zimm) Zare & Gams terhadap Biologi dan Populasi Kutudaun Myzus persicae Sulzer (Hemiptera: Aphididae) pada Tanaman Tembakau
Abstrak: Cendawan entomopatogen Lecanicillium lecanii tertentu dilaporkan sebagai endofit. Penelitian mengenai kemampuan L. lecanii endofit dalam mengendalikan kutudaun belum pernah dilaporkan di Indonesia. Tujuan dari penelitian ini adalah mengetahui kemampuan kolonisasi L. lecanii pada berbagai bagian tanaman tembakau dan pengaruhnya terhadap biologi dan populasi kutudaun M. persicae. Perlakuan terdiri atas empat macam, yaitu kontrol (K), perlakuan benih dengan L. lecanii selama 12 jam (P1), perlakuan bibit dengan penyemprotan L. lecanii seminggu setelah pindah tanam (P2), dan perlakuan kombinasi (P3), yaitu kombinasi P1 dan P2. Tanaman tembakau semua perlakuan diinfestasi kutudaun M. persicae seminggu setelah penyemprotan cendawan. Pengamatan yang dilakukan meliputi aspek biologi yang terdiri atas siklus hidup, keperidian, dan lama hidup serta populasi kutudaun. Penelitian ini menunjukkan bahwa L. lecanii uji mampu mengolonisasi daun tembakau secara endofitik. Cendawan L. lecanii endofit dapat memperlambat siklus hidup, menurunkan keperidian, dan memperpendek lama hidup sehingga menurunkan pertumbuhan populasi M. persicae.
Keyword: keperidian, pertumbuhan populasi, siklus hidup

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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