Judul: Kelimpahan Hama dan Predator pada Pertanaman Talas (Colocasia esculenta (L) Schoot) di Situ Gede, Bogor
Abstrak: Talas merupakan salah satu tanaman pangan yang berpotensi menjadi habitat serangga hama maupun predator. Informasi tentang kelimpahan hama dan predator pada pertanaman talas masih belum banyak diketahui. Tujuan dari penelitian ini adalah untuk memperoleh informasi kelimpahan dan perkembangan populasi hama serta predator pada pertanaman talas di kampung Cilubang Lebak, Kelurahan Situ Gede, Dramaga Bogor, Jawa Barat. Pengamatan dilakukan dengan menggunakan metode pengamatan langsung dan lubang perangkap (pitfall trap). Hasil pengamatan menunjukkan bahwa hama utama yang ditemukan pada tajuk tanaman talas adalah Oxya japonica, Empoasca sp. dan Aphis gossypii. Predator yang banyak ditemukan pada tanaman talas adalah Coccinellidae dan laba-laba Oxyophidae. Predator pada permukaan tanah di pertanaman talas didominasi oleh laba-laba Lycosidae dan kumbang Carabidae
Keyword: hama, kelimpahan, predator, talas

Judul: Kelimpahan Dan Keragaman Artorpoda Predator Dan Artropoda Lainnya Pada Tanaman Talas (Colocasia Esculenta (L) Schoott) Di Situ Gede, Bogor
Abstrak: Informasi kelimpahan dan keragaman artropoda predator dan artropoda lainnya pada tanaman talas diperlukan sebagai langkah awal dalam penerapan tehnik pengendalian hama terpadu (PHT). Tujuan penelitian ini adalah mengetahui kelimpahan dan keragaman artropoda predator dan artropoda lainnya pada tanaman talas di Situ Gede, Bogor. Metode yang digunakan dalam penelitian ini adalah pengamatan langsung, penggunaan perangkap (pitfall trap), dan sticky trap. Hasil penelitian menunjukkan bahwa artropoda herbivora memiliki kelimpahan tinggi, sementara artropoda predator lebih beragam. Proporsi artropoda sebagai predator, herbivora, detrivora, dan parasitoid pada pertanaman talas secara berturut-turut adalah 19%, 66%, 10%, 5%. Artropoda predator yang dominan adalah semut (Hymenoptera: Formicidae) sebanyak 1324 individu. Artropoda herbivora yang dominan adalah kutu daun (Hemiptera: Aphididae) sebanyak 11059 individu. Artropoda detrivora yang dominan adalah serangga pengurai tanah (Collembola: Entomobryidae) sebanyak 624 individu. Artropoda parasitoid yang dominan adalah Encyrtidae (Hymenoptera) sebanyak 456 individu.
Keyword: PHT, pitfall trap, sticky trap

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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