Judul: Potensi Beberapa Jenis Tanaman sebagai Atraktan dalam Pengendalian Hayati Hama Keong Mas (Pomacea canaliculata L.).
Abstrak: Keong mas (Pomacea canaliculata L.) adalah hewan invasif yang menjadi hama padi di areal persawahan. Pengendalian keong mas dapat dilakukan secara alami menggunakan tanaman sebagai atraktan. Penelitian ini bertujuan mengeksplorasi jenis tanaman dan waktu pengamatan yang membuat keong mas paling banyak mendekati tanaman. Penelitian dilakukan pada kolam berukuran 1.8 m x 1.8 m yang dibagi menjadi 9 blok. Sebanyak 200 individu keong mas berukuran kecil dan besar diletakkan pada blok ke-5 (di tengah), kemudian delapan blok di sekitarnya diletakkan satu jenis tanaman yang berbeda. Perpindahan keong mas mendekati jenis tanaman yang disukai diamati setiap 1 jam dari pukul 06.00 - 18.00 WIB. Pengamatan diulang sebanyak lima kali pada lima hari yang berbeda. Hasil pengamatan menunjukkan bahwa keong mas kecil paling banyak berpindah mendekati daun talas belitung (Xanthosoma sagittifolium) (7.9 ± 4.0 individu), sedangkan keong mas besar pada daun pepaya (Carica papaya) (7.1 ± 4.4 individu). Kedua tanaman tersebut yang paling berpotensi dijadikan atraktan. Jumlah keong mas pada tanaman ditemukan paling banyak pada pukul 18.00 WIB. Kata kunci: ABSTRACT LISDASARI PRIANDHINI. The Potenty of Several Plant Types as Attractants in Biological Control of Golden Apple Snail (Pomacea canaliculata L.). Supervised by TRI HERU WIDARTO and TATIK CHIKMAWATI. Golden apple snail (Pomacea canaliculata L.) is an invasive animal that becomes a destructive pest in rice fields. Controlling this snails can be done naturally using plants as attractants. This study aims to explore species plants and the duration of time needed that make the largest number of snails attracted to the plants. The study was conducted on a 1.8 m x 1.8 m pool divided into 9 blocks. A total of 200 small and large snails are placed in the 5th block (in the middle), then eight different blocks surrounding it were filled with one species of plant. The movement of snails toward a species of plant was observed every 1 hour from 06.00 AM to 06.00 PM. This trial was repeated five times in five consecutive days. The observations showed that most small snails moved towards belitung taro leaves (Xanthosoma sagittifolium) (7.9 ± 4.0 individu), while most large snails moved towards papaya leaves (Carica papaya) (7.1 ± 4.4 individu). Those two types of plants are the most potentially used as attractants. In addition, the largest number of snails found in the plants occurs at 18.00 WIB.
Keyword: Carica papaya, hama padi, keong mas, tanaman atraktan, Xanthosoma sagittifolium

Judul: Efektivitas Ekstrak Daun Nangka dan Daun Sukun sebagai Moluskisida Nabati terhadap Daya Hidup Keong Mas (Pomacea canaliculata Lamarck)
Abstrak: Golden apple snails (Pomacea canaliculata Lamarck) are pests that attack water plants, especiallypaddy field until 30 days old. One effort to eradicate the snails without leaving chemicals residue in plants is by the provision of natural pesticides such as molluscicides. Jackfruit and breadfruit leaves maybe used as natural molluscicides for snail because they contain saponins. This study aims to test the jackfruit leaf and breadfruit leaf extracts to the survival of snails and determine the effectiveness of the leaf extract based on the LC50. The experiment was conducted separately for small (operculum diameter 5-10 mm) and large golden snails (operculum diameter of 11-20 cm). During the experiment the snails were put in a jars filled with water without leaf extract as the control, and jars with leaf extract at a concentration of 5 g/L, 10 g/L, and 25 g/L as treatments. Observations were carried out by counting the number of snails survives after 24, 48, and 72 hours. The results were analyzed to obtain LC50 values. Jackfruit and breadfruit leaves extracts have potential as molluscicides, since they caused all the snails died on the third day of treatment (72 hours). Decreasing rate of their survival is faster at higher concentrations. The presence of mucus in the body of the dead snails showing symptoms of the effect of saponins. Inconsistent results seem appear on LC50 (24 and 48 hours) of breadfruit extract. LC50 of 24 hours (large snails) and 48 hours (small snails) since they are not detected at the treatment using jackfruit leaves. This suggests the need to redesign the method and the concentration used for better research results.
Keyword: snails., Bogor Agricultural University (IPB), breadfruit, Pomacea canaliculata, Pomacea canaliculata, molluscicides, jackfruit

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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