Judul: Pengaruh Provenansi dan Kondisi Pohon Sengon (Paraserianthes falcataria (L) Nielsen) terhadap Biologi Hama Boktor (Xystrocera festiva Pascoe) pada Artificial
Abstrak: Recently, Sengon tree (Paraserinthes falcataria (L) Nielsen) cultivation in the form of monoculture has been increasing with the increase of demand and price of sengon timber. Sengon tree has also been used extensively in the rehabilitation effort of degraded forest and land. Sengon cultivation in the form of monoculture, however has faced serious problem of insect attack, especially stem borer, namely Boktor (Xystrocera festiva Pascoe). The pest problem requires an appropriate control measures, because it can destroy a plantation. An effective and efficient control method has not been developed, however, due to lack of knowledge on insect biology and physiology. This report describes a study on boktor larvae conducted in Forest Entomology Laboratory, Faculty of Forest, IPB, starting February to April 2006. The purpose of study were to investigate the effect of different provenance and tree condition in an artificial diet on the growth and preference of boktor larvae. Results of the study could give information on the biology and behavior of boktor larvae, as well as the possible resistant provenance against the pest.
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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: 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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