Judul: Biologi hama penggerek tebu phragmatoecia castonea (hubner) (lepidoptera, cossidae)
Abstrak: Tujuan penelitian ini adalah untuk mempelajari bioekologi Phragmatoecia castanea (Hubner) (Lepidoptera, Cossidae) yang dasar. Penelitian terutama mencakup morfologi serangga, siklus hidup, perilaku, keperidian dan kesuburan serta musuh­ musuh alami. Dilakukan pula pengamatan tingkat serangan, saat terjadinya serangan dan gejala kerusakan tanaman tebu. Penelitian dilakukan di laboratorium dan di lapang. Ngengat Phragmatoecia castanea memiliki ciri-ciri sebagai berikut; antena bertipe pektinat. Pangkalnya bertipe bipektinat, selebihnya bertipe unipektinat. Perbedaan kelamin ngengat dapat diketahui dengan mengamati perbedaan perbandingan bagian antena bipektinat dengan unipektinat. Pada ngengat jantan mulai dari pangkal hingga kira-kira tiga per­empat bertipe bipektinat selebihnya bertipe unipektinat, sedangkan dari pada betina bagian bipektinat lebih pendek bila dibandingkan dengan bagian bipektinat pada jantan. Palpus sangat kecil, tertutup oleh sisik kepala yang berbentuk seperti bantalan. Sayap agak memanjang, ujung dan termen sayap melengkung dan tepinya rata. Ngengat jantan terdiri dari sebuah rambut kaku, tetapi pada ngengat betina terdiri dari enam rambut kaku.
Keyword: Argyroploce schistaceana;, Diatraeophaga stratalis;, Chilo auricilius;, Bogor Agricultural University;

Judul: Biologi phthorimaea operculella zell. (lepidoptera:gelechiidae) dan kerentanan beberapa varietas kentang terhadapnya
Abstrak: Phthorimaea operculella atau ulat umbi kentang, merupakan hama penting pada kentang karena menyerang tanaman di lapang dan umbi di gudang. Penelitian ini dimaksudkan untuk mendapatkan informasi mengenai (i) biologi ulat umbi kentang pada umbi kentang, dan (ii) kerentanan beberapa varietas kentang terhadap ulat umbi kentang. Penelitian dilakukan di laboratorium Ilmu Hama Tumbuhan, Departemen Ilmu Hama dan Penyakit Tumbuhan, Fakultas Pertanian Institut Pertanian Bogor. Dalam penelitian biologi digunakan 30 butir umbi kentang varietas Rapan 106 untuk penentuan masa perkembangan, keperidian ngengat betina dan mortalitas telur, dan 200 butir umbi varietas Rapan 106 untuk penentuan ciri instar. Setiap umbi diinokulasi dengan larva ulat umbi kentang yang baru keluar dari telur kemudian dipelihara secara individual dalam kurungan plastik. Setiap hari dilakukan pengambilan contoh sebanyak 10 ekor larva untuk menentukan banyaknya instar, ukuran tubuh larva serta warna dari setiap instar larva.
Keyword: Potato variety;, Ngengat;, Kepompong;, Bogor Agricultural University;

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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