Judul: Biologi larva boktor (Xystrocera festiva Pascoe) dalam makanan buatan (Artificial diet) dengan bahan dasar serbuk kayu sengon (Paraserianthes falcataria)
Abstrak: The constraints faced in the development of sengon plantation forest is that i he sengon trees are planted in monoculture condition, they are very susceptible t -oktor (Xystrocera festiva) pest attack. During larvae stadium, boktor pest, in s r h for food, will bore sengon tree stem. This boktor larvae activity causes age on sengon trees, and even could cause death of the sengon plants. Various e • rts to control this pest have been conducted, although the results are still not e ective yet. This phenomenon was related with lack of knowledge concerning goktor larvae, because activities of this larvae occured in the inside parts of s gon trees, which made them difficult to be observed directly in the field. erefore, observation in the laboratory will help providing information on the biol gy of boktor pest, which comprise growth, life cycle, and feeding behavior. Artificial diet is an artificial food consisting of natural ingredients and chemicals with certain amount of dosage as a substitute for host plant for boktor larvae, to allow easy observation in laboratory. Materials used in this research was sengon wood powder comprising those of ijanjarnegara provenance in sick condition, Banjamegara provenance in healtpy condition, Solomon provenance in sick condition, Solomon provenance in healt y condition (each of them has undergone process of freeze dry), yeast extr ct, streptomycin, sucrose, agar, aquadest, ascorbic acid (vitamin C), benzoate, vitamin B, NaCl, dolomite, olive oil and small size boktor larvae (1.5 - 2.3 cm). The observed variables were weight of larvae, length of larvae, diameter of larvae head, and weight of food consumed by the boktor larvae. Measurement and replacement of food was conducted each week for a period of 8 weeks. Results of analysis of variance showed that factor which gave the largest contribution in creating significant effect on larvae growth (larvae weight, larvae lengili, larvae head diameter) and amount of food consumed by boktor larvae, was provenance factor. On the other hand, factor of condition (sick or healthy cond"tion of the trees which provide the wood powder) did not give significant effe on all observed variables during 6 weeks period. Factor of condition exe ed its effect, only during week-7 and week-8. Graph pattern of average gro h of larvae weight and length showed that during week -5, larvae from all treatments, on the average, underwent significant decrease in length and weight. This was because during the week -5, many of the larvae underwent molting. Results of Duncan test showed that provenance which exerted the greatest effect was Solomon provenance. The best growth of boktor larvae was in Solomon provenance with larvae weight increment of 72 mg, larvae length increment of 4.47 pun, and larvae head increment of 0.67 mm. During 8 weeks observation in laboratory, feeding behavior of boktor larvae in artificial diet was similar with fi ing behavior of boktor larvae in trees in the field .
Keyword: sengon, artificial diet, boktor

Judul: Biologi larva boktor (Xystrocera festiva Pascoe) dalam makanan buatan (Artificial diet) dengan bahan dasar serbuk kayu sengon (Paraserianthes falcataria)
Abstrak: Kendala yang dihadapi dalam pembangunan hutan tanaman sengon yaitu pohon sengon yang ditanam secara monokultur sangat rentan terhadap serangan hama boktor (Xystrocera festiva). Pada stadium larva, hama poktor akan menggerek batang pohon sengon untuk menjadi makanannya. Aktivitas larva boktor ini menyebabkan kerusakan pada pohon sengon, bahkan sampai menyebabkan kematian pada tanaman sengon. Berbagai upaya pengendalian telah dilakukan namun hasilnya dirasakan masih belum efektif. Hal ini tidak terlepas dari kurangnya pengetahuan tentang larva boktor karena aktivitas larva ini terjadi pada bagian dalam pohon sengon sehingga sulit untuk mengamati secara langsung di lapangan. Oleh karena itu, pengamatan di laboratorium akan membantu memberi informasi tentang biologi hama boktor yang mencakup pertumbuhan, siklus hidup, dan aktivitas makan. Artificial diet merupakan makanan buatan yang terdiri dari bahan alami dan bahan kimia dengan dosis tertentu sebagai pengganti inang bagi larva boktor untuk mempermudah pengamatan di laboratorium. Bahan yang digunakan dalam penelitian ini yaitu serbuk kayu sengon yang terdiri dari provenan Banjarnegara kondisi sakit, provenan Banjarnegara kondisi sehat, provenan Solomon kondisi sakit, provenan Solomon kondisi sehat (masing- masing telah diproses freeze dry), yeast extract, streptomycin, sukrosa, agar, aquades, ascorbic acid (vitamin C), benzoat, vitamin B, NaCl, dolomit, minyak zaitun dan larva boktor berukuran kecil (1,52,3 cm). Parameter yang diamati yaitu berat larva, panjang larva, diameter kepala larva, dan berat makanan yang dikonsumsi oleh larva boktor. Pengukuran dan penggantian makanan dilakukan setiap minggu selama 8 minggu.
Keyword: sengon

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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