Judul: Population Dynamic of Bagworm, Clania tertia Templeton (Lepidoptera: Psychidae) on Immature Oil Palm in Estate Owned by PT Inti Indosawit Subur, Pelalawan Regency, Riau
Abstrak: Salah satu faktor yang mempengaruhi produksi kelapa sawit adalah serangan hama dan penyakit. Ulat pemakan daun kelapa sawit merupakan serangga hama yang sering ditemukan di seluruh perkebunan kelapa sawit Indonesia. Ulat kantung merupakan salah satu serangga pemakan daun yang tergolong rakus dan sulit dikendalikan karena hama ini bersembunyi di dalam kantungnya. Salah satu spesies ulat kantung yang sekarang banyak menyerang tanaman kelapa sawit adalah Clania tertia. Pengendalian hama ini perlu dilakukan terutama pada tanaman belum menghasilkan. Penelitian ini bertujuan mengetahui dinamika populasi ulat kantung, C. tertia pada kelapa sawit fase belum menghasilkan dan mengetahui faktor penyebab kematian ulat kantung di kebun milik PT Inti Indosawit Subur, Kabupaten Pelalawan, Riau. Penelitian ini dilakukan dengan pengamatan langsung terhadap ulat kantung di Blok A dan Blok K. Setiap blok ditentukan 2 lokasi pengamatan dan dipilih 25 tanaman contoh dari setiap lokasi pengamatan. Ulat kantung yang mati dikumpulkan untuk ditentukan penyebab kematiannya. Hasil penelitian menunjukkan bahwa populasi ulat kantung di Blok A lebih rendah dibandingkan Blok K karena di Blok K tidak dilakukan pengendalian seperti injeksi batang. Pada Blok A, serangga yang mati akibat insektisida paling tinggi terjadi pada pengamatan kedua dan setelah itu menurun pada setiap pengamatan. Ulat kantung yang mati di Blok K paling tinggi disebabkan oleh serangan predator., One of the affected factors of oil palm production is the attack of pests and diseases. Oil palm leaf-eating caterpillars are a insect pests often found in oil palm plantations throughout Indonesia. The bagworm is one of the leaf-eating insect that is classified as voracious and difficult to control because these pests hide in their bag. One species of bagworm have attacked oil palm plantations is Clania tertia. It is necessary to control this pest, especially on immature plants. This study aims to know the population dynamic of bagworm C. tertia on young oil palm and determine the factors causing the death of bagworm in estate owned by PT Inti Indosawit Subur, Pelalawan Regency, Riau. This study was conducted by direct observation of the bagworm in Block A and Block K. Two observation sites were determined from each block and 25 sample plants were selected from each observation site. The dead bagworms were collected to determine the cause of their death. The results showed that the bagworm population in Block A was lower than those of Block K, because there was no any control such as trunk injection in Block K were implemented. In Block A, the highest insect mortality due to insecticides occurred in the second observation and after that it decreased at each observation time. In Block K, the highest mortality of the bagworm was caused by predator attacks.
Keyword: bagworm, mortality, population dynamic, trunk injection

Judul: Keanekaragaman Hama dan Parasitoid pada Perkebunan Kelapa Sawit di Jambi
Abstrak: One of the most important ecosystem service is biological control since it provide natural control and prevents pest population build up. Biological control is quite widely practiced in various types of ecosystems, including in the oil palm plantations. One aspect that is important in the practice of biological control is parasitoid abundance and wealth, as natural enemies of pests of oil palm. The objective of this research was to study the diversity of pests and its parasitoids at various age levels in oil palm plantation. Field observations were conducted 4, 6, 8, and 10- years old of oil palm plantation in Jambi from February to April 2014. Insects were collected using direct observation and yellow pan trap (YPT). Traps were placed on the canopy and stem on 50x50 m plots (consisting of 36 palm trees). Pests that were collected from direct observation were reared and identified in the laboratory. Parasitoids which emerge from pests as well as from traps were all identified until morpho-species or species level. Overall, 525 individuals were collected. The most dominant pests found in the field was Lymantriidae. There was no correlation between pest abundance and age of oil palm. Nineteen species of parasitoids were found be associated with pests from the oil palm. The dominant parasitoids from the family Eulophidae and Braconidae. These parasitoids parasitized the dominant pest from Lymantriidae, Psychidae, and Limacodidae families with parasitization rate that varies from 1.61-14.29%. Pest populations affected by phenology and plant architecture cause movement and increased pest attack while parasitoid populations affected by the presence of flowering plants as food source of adult parasitoids.
Keyword: direct observation, habitat transformation, parasitoid, yellow pan trap

Judul: Sintesis Nanokristal Magnetit Menggunakan Urea sebagai Penjerap Cr(VI)
Abstrak: The study was to synthesize and characterize magnetite nanocrystal. Magnetite powder was synthesized using hydrothermal method from FeSO4 as precursor and sodium hydroxide and urea as the base sources. Characterization of the obtained powder was carried out using X-ray diffraction, scanning electron microscope, and energy dispersive X-ray analyzer. The crystallite size of magnetite by X-ray diffraction was obtained from 18,23 to 67,34 nm. The scanning electron microscope observations showed that magnetite particles underwent agglomeration. Magnetite powder was used as Cr(VI) adsorbent. The results showed that adsorption capacity for urea-based magnetite at pH 1-5 in 2 hours were 1.92; 1.91; 1.59; 1.20; and 1.21 mg/g, respectively. Adsorption capacity for sodium hydroxide-based magnetite (pH 1-5, 2 hours) were 1.74; 1.83; 0.64; 0.69; and 0.77 mg/g. The results indicated that urea-based magnetite is able to increase adsorption capacity.
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