Judul: New Assossiation between Gall-forming Insect Cecidochares connexa (M.) with Local Parasitoids in Polewali Mandar West Sulawesi
Abstrak: Chromoloaena odorata merupakan salah satu spesies gulma invasif yang masuk ke Indonesia dan menjadi gulma pada tanaman perkebunan. Salah satu teknik pengendalian yang telah dilakukan untuk mengendalikan gulma tersebut di Indonesia adalah dengan menggunakan serangga penyebab puru Cecidochares connexa (M) yang diintroduksi dari Colombia, Amerika Selatan pada tahun 1993. C. connexa telah dilepaskan di beberapa daerah di Indonesia termasuk Sulawesi pada tahun 1995-2000,. Walaupun introduksi C. connexa pernah dilakukan di Kecamatan Bantimurung, Kabupaten Maros, Sulawesi Selatan pada tahun 1999 akan tetapi informasi mengenai keberadaan dan kemapanan dari C. connexa di Sulawesi masih sangat minim. Penelitian ini bertujuan meneliti keberadaan C. connexa pada dua habitat berbeda dan asosiasi barunya dengan parasitoid lokal di Polewali Mandar, Sulawesi Barat. Penelitian dilakukan pada dua habitat yaitu lahan terbuka dan perkebunan kakao, pada empat desa berbeda, di Kecamatan Binuang, Kabupaten Polewali Mandar, Sulawesi Barat. Pemilihan tumbuhan sampel dilakukan secara purposive sampling, dengan mengumpulkan C. odorata yang memiliki puru. Tiga puluh C. odorata berpuru dikoleksi pada tiga lokasi berbeda setiap habitatnya. Pengamatan puru dimulai dengan mengkategorisasikan puru menjadi dua kelompok, yaitu puru yang tidak berlubang dan puru yang berlubang. Setiap puru dimasukkan ke dalam plastik zip-lock berukuran 8 cm x 12 cm. Pengukuran lubang puru dilakukan terhadap sampel puru dari lapang yang sudah berlubang. Puru yang tidak berlubang dipelihara sampai keluar serangga dan diidentifikasi di Laboratorium Pengendalian Hayati, Departemen Proteksi Tanaman, Institut Pertanian Bogor. Hasil penelitian menunjukkan adanya dua jenis serangga yang ditemukan berasosiasi dengan puru pada C. odorata, yaitu C. connexa (Diptera: Tephritidae) dan serangga famili Sciaridae (Diptera). C. connexa dapat ditemukan pada habitat lahan terbuka dan perkebunan kakao dan telah menyebar sampai di Polewali Mandar, Sulawesi Barat. Berdasarkan pengamatan, jumlah puru yang dapat ditemukan pada satu tumbuhan C. odorata berkisar antara 1-137 puru per C. odorata. Mayoritas tumbuhan C. odorata memiliki 1-10 puru per tumbuhan. Setiap puru dapat dihuni 1-5 individu C. connexa dan paling banyak ditemukan berkisar antara 1-2 individu per puru. Hasil penelitian menunjukkan adanya serangan parasitoid pada serangga puru C. connexa. Total ditemukan enam morfo-spesies parasitoid yang menyerang C. connexa. Parasitoid dominan adalah Aprostocetus sp.1 dengan tingkat parasitasi 13,57% pada lahan terbuka dan 10,63% di perkebunan kakao. Hasil penelitian ini menunjukkan bahwa telah terbentuk asosiasi baru antara seranga puru dengan serangga parasitoid lokal., Chromoloaena odorata (L) R.M. King & H. Rob is an invasive weed species that accidentally entered Indonesia and became a weed in plantation crops. One of the methods used to control the invasive weed C. odorata in Indonesia is Cecidochares connexa (M) which was introduced from Colombia, South America in 1993. C. connexa released in several areas of Indonesia, including Sulawesi In 1995-2000. Although the introduction of C. connexa was conducted in Bantimung sub-district, Maros Regency, South Sulawesi, in 1999, information about the presence and establishment of C. connexa in Sulawesi is still scarce. This study aims to determine the success of classic biological control on C. odorata and its new association with local parasitoids in Polewali Mandar, West Sulawesi. The research was conducted in two types of habitats, namely open fields and cocoa plantations, in four different villages within
Keyword: Interaksi baru, pengendalian biologi klasik, parasitoid, serangga puru, Classical biological control, gall insect, new interactions, parasitoids

Judul: Implikasi eksistensi chromolaena odorata (l.) King & robinson (asteraceae) dan agens hayatinya cecidochares connexa macquart (diptera: tephritidae) terhadap struktur komunitas serangga dan tumbuhan lokal
Abstrak: ALAL HUDA JAYA. S. Implication of existence both of Chromolaena odorata (L.) King & Robinson (Asteraceae) and its biological control agent - Cecidochares connexa Macquart (Diptera: Tephritidae) to local plant and insect community structure. Supervisors: DAMAYANTI BUCHORI and SOEKISMAN TJITROSEMITO. The aims of this research were (1) to study density and population distribution of C. odorata and its biological control agent - C. connexa, and (2) to study local plant and insect community structure in invaded area of C. odorata. Several activities have been conducted i.e. survey of research sites, vegetation analysis, and insect sampling. The study sites were selected base on purposive sampling method. All area located in Bogor district (Parung Panjang, Setu, Darmaga, Gunung Bunder, Ciawi, and Cisarua), Sukabumi district (Gunung Salak, Gunung Halimun, and Pakuwon), and Cianjur district. Analysis of vegetation were conducted using combination of transect and quadrate method. Insect were sampled by setting up several traps inside the plots. Pitfall trap and yellow pan trap were set up inside the plot, whereas malaise trap were placed between two transect lines. The result found that invasive exotic plant species (C. odorata) spread on whole study sites and well-growth on different habitat types (plantations, production forest, low land, and high land). Their population densities tend to decrease with increasing altitude. The occurrences of C. odorata co-exist with its biological control, the gall flies C. connexa. Almost all study sites (except Gunung Halimun and Cianjur) found these flies. Recently, C. connexa have established and wide spread, although the present of barrier (like mountain) is restriction factor for distribution of flies in West Java. Over 131.132 individual of plants consist of 21 families and 44 species were identified co-exist with C. odorata in Bogor area (Parung Panjang, Setu, Darmaga, and Gunung Bunder). In the same area, over 24.213 individual of insect consist of 14 orders, 132 families, and 568 species were found in C. odorata habitat. Three dominance insect orders i.e. Hymenoptera, Diptera, and Hemiptera were collected with high species richness and abundance. Implication of existence of C. odorata caused replacement local plant species and homogenization habitat on spatial scale. Introduction of C. odorata and its biological control agent caused and consequently associate with local insects.
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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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