Judul: Management Control of Stem Borer Zeuzera spp. (Lepidoptera: Cossidae) On Eucalyptus pellita F. Muell.
Abstrak: Pembangunan hutan tanaman industri menjadi salah satu solusi dalam memenuhi kebutuhan sumberdaya kayu baik di Indonesia maupun dunia. Namun, permasalahan dalam pembangunan hutan tanaman terutama jenis E. pellita adalah adanya serangan penggerek batang Zeuzera spp. yang dapat menurunkan produktivitas kayu. Perlu adanya konsep pengendalian secara terpadu dengan mengintegrasikan penggunaan agensia hayati dan kegiatan monitoring kerusakan. Tujuan dari penelitian ini ialah untuk menganalisis faktor yang berpengaruh terhadap kerusakan Zeuzera spp. dan mengidentifikasi musuh alaminya, menganalisis dinamika populasi Zeuzera spp., dan menganalisis potensi penggunaan cendawan entomopatogen dalam menginfeksi larva Zeuzera spp. Hasil survei menunjukan bahwa akumulasi kerusakan tertinggi terjadi pada Blok 5 (29%) dibandingkan Blok 6 (9%). Hasil analisis regresi berganda menunjukan bahwa faktor utama yang mempengaruhi kerusakan Zeuzera spp. adalah lokasi dan umur tanaman. Musuh alami Zeuzera spp. yang teridentifikas pada tegakan E. pellita dari kelompok parasitoid yakni Tetrastichus howardi (Hymenoptera: Eulophidae), dan Sisyropa sp. (Diptera: Tachinidae). Dinamika populasi Zeuzera spp. di hutan tanaman E. pellita menunjukkan penerbangan puncak pada bulan Oktober, diikuti kehadiran populasi cukup tinggi tangkapan ngengat dari akhir Mei hingga awal Juni. Inisiasi inokulasi B. bassiana pada larva Zeuzera spp. menunjukkan mortalitas 100% dengan rata-rata waktu infeksi tertinggi pada 5 hari setelah aplikasi. Hasil uji aplikasi entomopatogen B. bassiana menggunakan injeksi (67.44%) maupun semprot (65.52%) berpengaruh secara nyata terhadap tingkat infeksi Zeuzera spp. pada batang E. pellita. Jenis entomopatogen dengan kerapatan konidia diketahui berpengaruh nyata terhadap mortalitas larva Zeuzera spp. dengan perlakuan yang berbeda nyata dengan kontrol yaitu MA 108 ml-1, MM 108 ml-1, BB 106 ml-1, BB 108 ml-1, dan BB 104 ml-1. Aplikasi tiga jenis entomopatogen pada tanaman muda E. pellita belum berpengaruh nyata terhadap gejala dan tanda awal Zeuzera spp. terinfeksi., Developing industrial plantation forests is one of the solutions to keep the demand for wood resources both in Indonesia and the world. However, the problem in developing forest plantations, especially E. pellita is the red stem borer Zeuzera spp., which can reduce wood productivity. Integrated pest management require to control this insect pest with biological agents and monitoring to observe the level of damage. The aim of this study is to analyze the factors that affecting the damage by Zeuzera spp. and identify natural enemies, analyze the population dynamics of Zeuzera spp., and analyze the potential use of the entomopathogenic fungi in infecting Zeuzera spp. larvae. The survey results showed that the highest damage accumulation of Zeuzera spp. occurred in Block 5 (29%) compared to Block 6 (9%). The results of the multi-regression analysis show that the main factors affecting the damage by Zeuzera spp. are the location and age of the plant. Natural enemies of Zeuzera spp. have been identified on E. pellita plantation from the parasitoids group, namely Tetrastichus howardi (Hymenoptera: Eulophidae) and Sisyropa sp. (Diptera: Tachinidae). Population dynamics of Zeuzera spp. in E. pellita forest plantations showed peak flight occurred in October, followed by a reasonably high population presence of moth hatched from late May to early June. Initial inoculation of B. bassiana on Zeuzera spp. showed 100% mortality with the highest mean infection time five days after application. The test results for
Keyword: Entomopatogen, feromon, monitoring, parasitoid, penggerek

Judul: Tingkat Serangan, Kerusakan dan Potensi Biokontrol oleh Puru Daun Eucalyptus, Leptocybe invasa (Fisher & La Salle) dan Ophelimus maskelli (Ashmead) (Hymenoptera: Eulophidae), di Tanzania
Abstrak: In Tanzania, eucalypts are a significant fast-growing hardwood tree used to produce wood, paper, timbers, poles, bioenergy, and numerous other minor goods and services. Tanzania introduced eucalypts in the 1890s intending to supplement wood supplies from natural forests. Eucalyptus spp. is the world's most widely planted hardwood timber species, native to Australia, Indonesia, the Philippines, Timor, and New Guinea. Distribution is attributable to the ability exceptionally adapt to diverse ecological conditions and the substantially arraying products and services they offer. Leptocybe invasa and Ophelimus maskelli, two common Australian wasps (Hymenoptera: Eulophidae), have caused significant damage to eucalypt plantations in Tanzania since 2005 by inducing galls on petioles, young stems, and leaves that inhibit vascular bundle conductivity and photosynthesis. Although biological control is seen as the greatest option for conventional control measures from an ecological and financial standpoint so far, no eucalyptus gall wasp parasitoids have been documented or reported. Similarly, the number of parasitoid species and their parasitic capacity is unknown. Due to limited knowledge and literature. Therefore this study was set out to examine the current infestation, damage severity, and to identify potential natural enemies for controlling this pest in Tanzania. The research was conducted from October 2021 to August 2022 in three government-owned plantation forests, namely the Korogwe, Morogoro and North Ruvu forests that were planted with several Eucalypt spp. Samplings were done using systematic approach and field assessments involved examination of infested crown parts, highly infested species, and invasive capacity of gall inducers by counting and measuring gall length and diameter. Few selected trees were used to assess damage severity. Galls from infested eucalypt germplasms were collected and reared in the laboratory until the wasp emerges. The emerged wasps were primarily sorted and identified using morphological characters (Keys) under a stereomicroscope at the Sokoine University of Agriculture, Tanzania, and the Insect Biosystematics Laboratory at IPB University, Indonesia. Data were analyzed using Ms Excel, Minitab 19, and R statistical software. The analysis included computations of percentages of infestation and parasitoid parasitization, averages of galls per tree, and the relationship between stand altitudes and the infestation magnitude, damage index, and gall inducers. The results were summarized in tables and graphs and included in this final thesis. The results indicated that clonal hybrids were highly infested than E. tereticornis this may be due to poor adaptation less tolerance and resistance traits of clones compared to E.tereticornis raised from seeds. The middle and lower tree crown parts were highly infested compared to upper canopy. L. invasa had a higher invasive capacity in all locations and both host plants than O. maskelli. Damage severity generally ranked as severe in all eucalyptus germplasms assessed. Two species of parasitoids of eucalyptus gall-inducers were identified as Megastigmus sp. and Quadrastichus mendeli. Parasitization rates (collectively) in Korogwe, North Ruvu, and Morogoro forest plantations were 29.7%, 64%, and 33.3%, respectively. A higher parasitization rate was recorded from L. invasa galls on E. grandis x E. camaldulensis clones. Ecological factors such as temperature, wind, and rainfall influenced gall wasp infestations. Control efforts should focus on biological control agent candidates including
Keyword: Biocontrol, Eucalypts gall wasps, Forest damage, and Forest pests

Judul: Invers dari Matriks Tridiagonal Jacobi
Abstrak: Suatu matriks berukuran n×n dinamakan matriks tridiagonal jika untuk . Karya ilmiah ini memberikan algoritma yang mudah untuk menemukan invers ( dari matriks tridiagonal Jacobi yang simetrik dan nonsimetrik. Setiap elemen pada matriks tridiagonal ini adalah bilangan real. Terdapat 3 lema dan 2 teorema untuk menentukan . Lema pertama menunjukkan persamaan utama dalam membuktikan lema-lema dan teorema-teorema selanjutnya. Invers dari matriks yang simetrik dibuktikan oleh lema kedua yang menunjukkan elemen-elemen baris ke- dari . Selanjutnya, lema kedua dilengkapi dengan teorema pertama yang menunjukkan elemen-elemen dengan . Invers dari matriks yang nonsimetrik dibuktikan oleh lema ketiga yang menunjukkan elemen-elemen dengan dan elemen-elemen dengan dibuktikankan oleh teorema kedua.
Keyword: symmetric, nonsymmetric, matrix