Judul: Eksplorasi Cendawan Entomophthorales pada Beberapa Spesies Kutuputih dan Kutukapuk pada Berbagai Tanaman Hias di Bogor dan Cianjur
Abstrak: The ornamental plants are the ones of the high economic valued horticultural crops that have beauty and a certain appeal. However, there are several problems of the cultivation efforts to meet consumen desire to face a variety of problems, especially plant pests (OPT), such as insect pests, fungi, bacteria, viruses, and nematodes. The mealybugs (Hemiptera: Pseudococcidae) and ground pearls (Hemiptera: Margarodidae) have been considered as the important pests causing seriously problems in ornamental plants. The objective of this research was to explore the Entomophthoralean fungi associated with several species of mealybugs and ground pearls. The insects were sampled from September 2012 until February 2013, at the Village Babakan raya (District Darmaga) and Cibeber District, Cianjur. There were five sampled ornamental plants. Fifty insects were sampled from each plant. The samples were preserved in 30 ml screw cup vials filled with 70% alcohol. These were later processed in the laboratory to confirm presence of entomophthorealan fungus. Microscope slide squash mounts in lactophenol cotton blue were made for the insects on each plant. Each insect was examined with a microscope to determine if secondary conidia, hyphal bodies, conidiophores, primary conidia, and resting spores were present. Developmental stages of the fungus founded were hyphal bodies, primary conidia, secondary conidia, and saprophytic fungi. The fungus infection in mealybug and ground pearls was very different. There was no fungus infection on the ground pearls scoop in ornamental plant, jasmine and anthurium. The entomophthoralean fungus occurred on mealybug in the garden croton, Aspar and Agave with high levels of fungus infection.
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Judul: Keanekaragaman Kutu Putih (Hemiptera:  Pseudococcidae) dan Cendawan Entomophthorales pada Berbagai Tanaman di  Kabupaten Bogor
Abstrak: Hama dan penyakit tanaman merupakan salah satu faktor penyebab menurunnya produktivitas tanaman budi daya. Hama kutu putih merupakan serangga yang umum ditemukan pada tanaman budi daya. Serangga ini bersifat polifag yang memiliki inang dari berbagai famili tanaman. Kutu putih umumnya ditemukan secara berkelompok pada bagian tanaman yang terserang dan menghisap cairan tanaman. Cendawan Entomophthorales merupakan salah satu musuh alami kutu putih. Gejala lanjut dari kutu putih yang terinfeksi cendawan Entomophthorales yaitu tubuh kutu putih berwarna abu-abu atau hitam. Tujuan dari penelitian ini adalah untuk mengetahui keanekaragaman kutu putih dan asosiasinya dengan cendawan Entomophthorales pada berbagai tanaman inang. Kutu putih dikoleksi dari tanaman alpukat, biriba, bisbul, jambu kristal, jeruk nipis, nanas, pakcoy, pisang, dan singkong. Kutu putih yang ditemukan sebanyak tujuh spesies, yaitu Dysmicoccus brevipes, Dysmicoccus lepelleyi, Exallomochlus hispidus, Ferrisia virgata, Nipaecoccus sp., Paracoccus marginatus, dan Rastrococcus marginatus. Hanya satu spesies kutu putih yang terinfeksi cendawan Entomophthorales yaitu P. marginatus yang ditemukan pada tanaman pepaya dan singkong. Fase cendawan pada kedua tanaman inang yang ditemukan pada P. marginatus adalah hyphal bodies., Plant pests and diseases are one factor cause decrease in the productivity of cultivated plants. The mealybug pests are common insect pest found on cultivated plants. These insects are polyphagous and have hosts from various plant groups. Mealybugs are generally found in clusters on infested plant parts and suck plant fluids. The entomophthoralean fungus is one of the natural enemies of mealybugs. Mealybugs with gray or black bodies are signs of advanced Entomophthoralean fungal infection. The objective of these research is to determine diversity of mealybugs and it is associated with their entomophthoralean fungus on various cultivated plants. Mealybugs were collected from avocado, biriba, bisbul, crystal guava, lime, pineapple, pakcoy, banana and cassava plants. There are seven species of Mealybugs found during this research: Dysmicoccus brevipes, D. lepelleyi, Exallomochlus hispidus, Ferrisia virgata, Nipaecoccus sp., Paracoccus marginatus, and Rastrococcus spinosus. Only one of mealybugs infected by entomophthoralean fungus is P. marginatus on papaya and cassava plants. Fungal phase on both hosts which found on to be infective P. marginatus is the hyphal body.
Keyword: hyphal bodies, P. marginatus, polyphages

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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