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: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix