Judul: Penggulung daun Sylepta sp. (Lepidoptera: Crambidae) pada Boehmeria minuticymosa (Urticaceae):
Abstrak: Sylepta sp. (Lepidoptera: Crambidae) merupakan kelompok hama yang bersifat polifag. Larva hama ini menyebabkan daun menggulung. Salah satu tanaman inang hama ini adalah gulma Boehmeria minuticymosa N. Acharya & Yonek (Urticaceae). Larva sering diparasit oleh beberapa parasitoid, sehingga bisa bermanfaat sebagai inang alternatif parasitoid dalam pengendalian biologi. Tujuan dari penelitian ini yaitu mengamati beberapa aspek biologi hama ini dan parasitoidnya pada B. minuticymosa. Penelitian dilaksanakan di Laboratorium Biosistematika Serangga, Departemen Proteksi Tanaman, Fakultas Pertanian, Institut Pertanian Bogor, dari bulan Februari hingga Agustus 2018. Larva Sylepta sp. diperoleh dari lapangan dan dipelihara di laboratorium. Aspek biologi yang diamati meliputi jumlah instar larva, stadium larva dan pupa, lama hidup imago, dan parasitoidnya. Hasil penelitian menunjukkan bahwa Sylepta sp. memiliki empat instar. Rata-rata stadium larva dan pupa adalah 19.59 dan 8.33 hari. Larva menggulung daun dan memakannya dari bagian dalam daun. Pupa berwana cokelat gelap. Lama hidup imago jantan dan betina adalah 4.18 dan 6.09 hari. Parasitoid dari hama ini termasuk Ordo Hymenoptera, Famili Braconidae dan Bethylidae (parasitoid larva) dan Chalcididae (parasitoid pupa).
Keyword: gulma, hama, Hymenoptera, serangga, Urticaceae

Judul: Penggulung Daun Sylepta sp. (Lepidoptera: Crambidae) pada Boehmeria minuticymosa: Serangan di Lapangan dan Parasitoidnya
Abstrak: Boehmeria (Urticaceae) terdiri atas 100 spesies dan tersebar di daerah tropis di Asia, Oceania, dan Amerika. Salah satu spesies dari genus ini, B. minuticymosa, dikenal sebagai gulma yang tumbuh di dekat danau, sungai, atau tempat lain di dekat sumber air. Gulma ini sering diserang oleh larva Sylepta sp. (Lepidoptera: Crambidae). Larva sering diparasit oleh parasitoid, sehingga bisa berperan sebagai inang alternatif ketika larva inang tidak tersedia di lapangan. Tujuan penelitian ini adalah untuk mengamati infestasi larva Sylepta sp. pada B. minuticymosa, dan untuk mengamati parasitoid dan tingkat parasitisasinya di Bogor. Pengamatan Sylepta sp. dan parasitoidnya dilakukan pada sembilan lokasi di tiga desa di Bogor, dari Februari hingga November 2017. Larva dan parasitoid dipelihara di Laboratorium Biosistematika Serangga, Departemen Proteksi Tanaman, Fakultas Pertanian, Institut Pertanian Bogor. Untuk mengamati infestasi Sylepta sp., di setiap lokasi ditentukan empat tanaman. Pada setiap tanaman dihitung jumlah total daun dan daun yang menggulung. Untuk mengamati parasitoid, 50 daun menggulung yang berisi larva dikumpulkan dan dipelihara di laboratorium. Parasitoid yang muncul dari larva inang diidentifikasi dan dihitung tingkat parasitisasinya. Hasil penelitian menunjukkan bahwa serangan Sylepta sp. rata-rata di Bogor 30%. Parasitoid yang muncul dari larva yang terparasit adalah Ordo Hymenoptera, Famili Braconidae. Parasitisasi parasitoid di lapangan adalah 0.12%.
Keyword: Braconidae, gulma, penggulung daun, Urticaceae

Judul: The Effects of Variance of Interest rate to Variance of Annuity Future Values
Abstrak: Time value of money is a concept that refers to the difference of the value of money due to time difference. The value of money for present time would not be the same as the value of money in the future. The value of money for present time is called as Present Value (PV) of the money and the value of money for future time is called Future Value (FV) of the money. Determination the value of money, for present and future time, depends on the time and rate of return. The value of money is determined by several factors such as inflation, fluctuation of interest rates, and government policy in securities and taxation. Due to fluctuation of the value of money we need a FV formulation, it is useful for knowing whether an investment can be profitable or not, and this information is useful also in budget analysis. Annuity is defined as a series of payments made for a specific period. The payment, fixed or varied, can be made at the beginning or at the end of the period. Annuity paid at the beginning of the period is called annuity-due and annuity paid at the end of the period is called immediate annuity-certain. The accumulated value of the annuity after few years later is called as a final value or a future value. Burnecki et al. (2003) have discussed about the FV of a fixed-rate annuity in which payments are made according to the arithmetic or geometric series. They have also examined FV for annuities in which payments are made according to arithmetic or geometric series with random rates of interest. This paper examines FV for annuity-due in which payments are made according to arithmetic or geometric series with interest rates as a random variable, which is normal distribution ,  . Future value formula is expressed in recursive form. FV for annuity-due which payments are made according to the arithmetic or geometric series with random rates of interest is calculated by theoretical way and simulation way. The random rates of interest is denoted as k k i  i  , where k i an independent random variable; i is a constant and k  is a random variable which has normal distribution ,  . By using the determined parameters, a sequence of random rates of interest are generated for theoretical calculation. Meanwhile for the simulation, the random rates of interest is generated 1000 times for the simulation. The generated data give mean value, variance, and standard deviation. Moreover, error of mean value, variance, and standard deviation from the theoretical and simulation results are calculated. Error calculation uses Symmetric Mean Absolute Percentage Error (SMAPE). The smaller the value of SMAPE is the more accurate the simulation. The interest rate variances are varied from 0.000036 to 0.0001 to study the relationship between variance of rates of interest and variance of future value. The theoretical and simulation results show that when the variance of random rates of interest increases, then the variance of FV increases linearly. FV of the annuity-due in
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