Judul: Species, Distribution, And Host Plants Of Scale Insects, Family Monophlebids (Hemiptera) In Indonesia
Abstrak: Kutu sisik termasuk dalam Superfamili Coccoidea, Ordo Hemiptera, termasuk Famili Monophlebidae. Penelitian tentang berbagai aspek kutu sisik di Indonesia relatif sedikit, meskipun sebagian menjadi hama penting pertanian. Genus Icerya merupakan salah satu kutu sisik yang banyak dikenal sebagai hama pertanian. Tujuan dari penelitian ini adalah untuk mengumpulkan informasi terkini mengenai spesies, persebaran, dan tanaman inang serangga Famili Monophlebidae yang telah dilaporkan di Indonesia. Penelitian ini merupakan ‘review’ dengan menggunakan data sekunder melalui tahapan pengumpulan data, analisis informasi yang diperoleh, penfasiran hasil, dan pembahasan serta kesimpulan. Berdasarkan data yang diperoleh, terdapat 26 spesies serangga kutu sisik Famili Monophlebidae di Indonesia. Spesies kutu sisik yang paling beragam dalam famili ini dilaporkan dari Pulau Jawa, yaitu sebanyak 15 spesies, diikuti Papua delapan spesies, Sumatra tujuh spesies, Sulawesi lima spesies, Kalimantan tiga spesies, serta Bali dan Nusa Tenggara Timur masing-masing satu spesies. Icerya purchasi merupakan salah satu spesies kutu sisik Famili Monophlebidae terpenting karena bersifat sangat polifag dan sebaran di Indonesia sangat luas dibanding spesies lainnya. Terdapat tiga spesies endemik dari wilayah Papuayaitu Etropera papuensis, Monophlebulus enarotalicus, dan M. gressitti. Meskipun kutu sisik Famili Monophlebidae penting dalam pertanian, namun keanekaragaman dan tanaman inang di Indonesia masih kurang dieksplorasi., Scale insects belong to the Superfamily Coccoidea, Order Hemiptera, and Family Monophlebidae. Despite the importance of some species as agricultural pests, research on various aspects of scale insects in Indonesia is relatively scarce. The genus Icerya is among the well-known agricultural pests within scale insects. This study aims to gather current information regarding the species, distribution, and host plants of insects in the Family Monophlebidae reported in Indonesia. This review utilizes secondary data through stages of data collection, analysis, interpretation of results, discussion, and conclusions. Based on the data obtained, there are 26 species of scale insects in the Family Monophlebidae reported in Indonesia. The most diverse species of scale insects in this family are found on the island of Java, with 15 species, followed by Papua with eight species, Sumatra with seven species, Sulawesi with five species, Kalimantan with three species, and Bali and East Nusa Tenggara each with one species. Icerya purchasi is one of the most important species of scale insects in the Family Monophlebidae due to its highly polyphagous nature and wide distribution in Indonesia compared to other species. There are three endemic species from the Papua region: Etropera papuensis, Monophlebulus enarotalicus, and M. gressitti. Although scale insects in the Family Monophlebidae are important in agriculture, their diversity and host plants in Indonesia remain underexplored.
Keyword: Pertanian, Agriculture, Coccoidea, hama tanaman, spesies endemik, endemic species, insect pests, Monophlebidae, Icerya

Judul: Tinjauan Spesies Kutudaun (Hemiptera: Aphididae) dan Tumbuhan Inangnya Di Indonesia
Abstrak: Kutudaun merupakan salah satu kelompok hama penting pada berbagai tanaman budi daya. Kelimpahan populasi kutudaun yang tinggi dapat menyebabkan kerusakan langsung maupun tidak langsung. Kutudaun di Indonesia telah banyak dilaporkan oleh beberapa penulis sehingga menunjukkan tingkat kekayaan spesies yang tinggi. Penelitian ini bertujuan menghimpun informasi spesies kutudaun (Hemiptera: Aphididae) dan tumbuhan inangnya di Indonesia. Penelitian ini dilakukan dengan metode studi pustaka. Data sekunder yang dihimpun berasal dari buku, jurnal, tesis, dan disertasi. Data terdiri atas spesies, subfamili, tribe, nama umum, sinonim, distribusi, peranan, tumbuhan inang, dan referensi. Metode terdiri atas pengumpulan data, pengolahan data, analisis data, penyajian dan penarikan simpulan. Hasil yang diperoleh dari 153 literatur adalah jumlah spesies kutudaun di Indonesia mencapai 226 spesies dari 79 genus dan 8 subfamili kutudaun yang tersebar di seluruh Indonesia. Aphidinae adalah subfamili dominan di Indonesia. Total 226 spesies kutudaun yang dilaporkan, 27 spesies ditemukan pada tanaman pangan, 48 spesies pada tanaman perkebunan, 102 spesies pada tanaman hortikultura, dan 153 spesies ditemukan pada tumbuhan lainnya. Spesies kutudaun terbanyak berada di pulau Jawa yaitu 217 spesies. Kisaran inang kutudaun mencapai 745 spesies dari 117 famili tumbuhan inang. Aphis gossypii merupakan spesies dengan jumlah tumbuhan inang terbanyak dengan 159 spesies dari 50 famili tumbuhan inang., Aphid is one of the most important pest groups in the various cultivated plants. The high abundance of aphids can cause seriously direct and indirect damage. Aphids in Indonesia has been reported in Indonesia by many authors, thus showing a high diversity of aphid species. This study aims to collect information aphid species (Hemiptera: Aphididae) and its host plants in Indonesia. This kind of research is a literature study. The secondary data was collected from books, journals, thesis, dissertation, and others. Data consists of species, subfamily, tribe, common name, synonymous, distribution, role, host plants, and reference. Method stages are data collection, data processing, data analysis, data display and conclusion drawing. Results of the aphids reports from 153 literatures show that the number of aphids in Indonesia reached 226 species from 79 genus and 8 subfamily distributed throughout Indonesia. Aphidinae is the dominant subfamily in Indonesia. A total of 226 species were reported, 27 of them were found on food crops, 48 on estate crops, 102 on horticultural crops, 153 on other plants. Java island has the highest number of reported aphid species which is can reach 217 species. There are 745 species from 117 plant families serving as the host of aphids in Indonesia. Aphis gossypii has the highest number of host range with 159 species from 50 plant families.
Keyword: aphid, aphids in Indonesia, checklist of aphids, diversity, host plant

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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